diff --git a/src/ol/geom/flat/flipflatgeom.js b/src/ol/geom/flat/flipflatgeom.js
index 8532682e46..5808999797 100644
--- a/src/ol/geom/flat/flipflatgeom.js
+++ b/src/ol/geom/flat/flipflatgeom.js
@@ -17,7 +17,7 @@ ol.geom.flat.flip.flipXY =
   var dest, destOffset;
   if (opt_dest !== undefined) {
     dest = opt_dest;
-    destOffset = goog.isDef(opt_destOffset) ? opt_destOffset : 0;
+    destOffset = opt_destOffset !== undefined ? opt_destOffset : 0;
   } else {
     goog.asserts.assert(opt_destOffset === undefined,
         'opt_destOffSet should be defined');
diff --git a/src/ol/geom/flat/inflateflatgeom.js b/src/ol/geom/flat/inflateflatgeom.js
index 53c4620c3f..e61c194f08 100644
--- a/src/ol/geom/flat/inflateflatgeom.js
+++ b/src/ol/geom/flat/inflateflatgeom.js
@@ -11,7 +11,7 @@ goog.provide('ol.geom.flat.inflate');
  */
 ol.geom.flat.inflate.coordinates =
     function(flatCoordinates, offset, end, stride, opt_coordinates) {
-  var coordinates = goog.isDef(opt_coordinates) ? opt_coordinates : [];
+  var coordinates = opt_coordinates !== undefined ? opt_coordinates : [];
   var i = 0;
   var j;
   for (j = offset; j < end; j += stride) {
@@ -32,7 +32,7 @@ ol.geom.flat.inflate.coordinates =
  */
 ol.geom.flat.inflate.coordinatess =
     function(flatCoordinates, offset, ends, stride, opt_coordinatess) {
-  var coordinatess = goog.isDef(opt_coordinatess) ? opt_coordinatess : [];
+  var coordinatess = opt_coordinatess !== undefined ? opt_coordinatess : [];
   var i = 0;
   var j, jj;
   for (j = 0, jj = ends.length; j < jj; ++j) {
@@ -57,7 +57,7 @@ ol.geom.flat.inflate.coordinatess =
  */
 ol.geom.flat.inflate.coordinatesss =
     function(flatCoordinates, offset, endss, stride, opt_coordinatesss) {
-  var coordinatesss = goog.isDef(opt_coordinatesss) ? opt_coordinatesss : [];
+  var coordinatesss = opt_coordinatesss !== undefined ? opt_coordinatesss : [];
   var i = 0;
   var j, jj;
   for (j = 0, jj = endss.length; j < jj; ++j) {
diff --git a/src/ol/geom/flat/simplifyflatgeom.js b/src/ol/geom/flat/simplifyflatgeom.js
index 7b747c6280..9e1c45cc9d 100644
--- a/src/ol/geom/flat/simplifyflatgeom.js
+++ b/src/ol/geom/flat/simplifyflatgeom.js
@@ -42,7 +42,7 @@ goog.require('ol.math');
  */
 ol.geom.flat.simplify.lineString = function(flatCoordinates, offset, end,
     stride, squaredTolerance, highQuality, opt_simplifiedFlatCoordinates) {
-  var simplifiedFlatCoordinates = goog.isDef(opt_simplifiedFlatCoordinates) ?
+  var simplifiedFlatCoordinates = opt_simplifiedFlatCoordinates !== undefined ?
       opt_simplifiedFlatCoordinates : [];
   if (!highQuality) {
     end = ol.geom.flat.simplify.radialDistance(flatCoordinates, offset, end,
diff --git a/src/ol/graticule.js b/src/ol/graticule.js
index ab3b84dc98..3a3ca588b7 100644
--- a/src/ol/graticule.js
+++ b/src/ol/graticule.js
@@ -463,18 +463,18 @@ ol.Graticule.prototype.updateProjectionInfo_ = function(projection) {
   var minLonP = worldExtentP[0];
 
   goog.asserts.assert(!goog.isNull(extent), 'extent cannot be null');
-  goog.asserts.assert(goog.isDef(maxLat), 'maxLat should be defined');
-  goog.asserts.assert(goog.isDef(maxLon), 'maxLon should be defined');
-  goog.asserts.assert(goog.isDef(minLat), 'minLat should be defined');
-  goog.asserts.assert(goog.isDef(minLon), 'minLon should be defined');
+  goog.asserts.assert(maxLat !== undefined, 'maxLat should be defined');
+  goog.asserts.assert(maxLon !== undefined, 'maxLon should be defined');
+  goog.asserts.assert(minLat !== undefined, 'minLat should be defined');
+  goog.asserts.assert(minLon !== undefined, 'minLon should be defined');
 
-  goog.asserts.assert(goog.isDef(maxLatP),
+  goog.asserts.assert(maxLatP !== undefined,
       'projected maxLat should be defined');
-  goog.asserts.assert(goog.isDef(maxLonP),
+  goog.asserts.assert(maxLonP !== undefined,
       'projected maxLon should be defined');
-  goog.asserts.assert(goog.isDef(minLatP),
+  goog.asserts.assert(minLatP !== undefined,
       'projected minLat should be defined');
-  goog.asserts.assert(goog.isDef(minLonP),
+  goog.asserts.assert(minLonP !== undefined,
       'projected minLon should be defined');
 
   this.maxLat_ = maxLat;
diff --git a/src/ol/imagecanvas.js b/src/ol/imagecanvas.js
index 3d903bab06..0d1920d304 100644
--- a/src/ol/imagecanvas.js
+++ b/src/ol/imagecanvas.js
@@ -25,9 +25,9 @@ ol.ImageCanvas = function(extent, resolution, pixelRatio, attributions,
    * @type {?ol.ImageCanvasLoader}
    * @private
    */
-  this.loader_ = goog.isDef(opt_loader) ? opt_loader : null;
+  this.loader_ = opt_loader !== undefined ? opt_loader : null;
 
-  var state = goog.isDef(opt_loader) ?
+  var state = opt_loader !== undefined ?
       ol.ImageState.IDLE : ol.ImageState.LOADED;
 
   goog.base(this, extent, resolution, pixelRatio, state, attributions);
diff --git a/src/ol/layer/layergroup.js b/src/ol/layer/layergroup.js
index 0e2c6e84d9..647a882407 100644
--- a/src/ol/layer/layergroup.js
+++ b/src/ol/layer/layergroup.js
@@ -191,7 +191,7 @@ ol.layer.Group.prototype.setLayers = function(layers) {
  * @inheritDoc
  */
 ol.layer.Group.prototype.getLayersArray = function(opt_array) {
-  var array = goog.isDef(opt_array) ? opt_array : [];
+  var array = opt_array !== undefined ? opt_array : [];
   this.getLayers().forEach(function(layer) {
     layer.getLayersArray(array);
   });
@@ -203,7 +203,7 @@ ol.layer.Group.prototype.getLayersArray = function(opt_array) {
  * @inheritDoc
  */
 ol.layer.Group.prototype.getLayerStatesArray = function(opt_states) {
-  var states = goog.isDef(opt_states) ? opt_states : [];
+  var states = opt_states !== undefined ? opt_states : [];
 
   var pos = states.length;
 
diff --git a/src/ol/map.js b/src/ol/map.js
index c9eb514a7d..acb08063c9 100644
--- a/src/ol/map.js
+++ b/src/ol/map.js
@@ -496,7 +496,7 @@ goog.inherits(ol.Map, ol.Object);
  */
 ol.Map.prototype.addControl = function(control) {
   var controls = this.getControls();
-  goog.asserts.assert(goog.isDef(controls), 'controls should be defined');
+  goog.asserts.assert(controls !== undefined, 'controls should be defined');
   controls.push(control);
 };
 
@@ -508,7 +508,7 @@ ol.Map.prototype.addControl = function(control) {
  */
 ol.Map.prototype.addInteraction = function(interaction) {
   var interactions = this.getInteractions();
-  goog.asserts.assert(goog.isDef(interactions),
+  goog.asserts.assert(interactions !== undefined,
       'interactions should be defined');
   interactions.push(interaction);
 };
@@ -534,7 +534,7 @@ ol.Map.prototype.addLayer = function(layer) {
  */
 ol.Map.prototype.addOverlay = function(overlay) {
   var overlays = this.getOverlays();
-  goog.asserts.assert(goog.isDef(overlays), 'overlays should be defined');
+  goog.asserts.assert(overlays !== undefined, 'overlays should be defined');
   overlays.push(overlay);
 };
 
@@ -600,10 +600,10 @@ ol.Map.prototype.forEachFeatureAtPixel =
     return;
   }
   var coordinate = this.getCoordinateFromPixel(pixel);
-  var thisArg = goog.isDef(opt_this) ? opt_this : null;
-  var layerFilter = goog.isDef(opt_layerFilter) ?
+  var thisArg = opt_this !== undefined ? opt_this : null;
+  var layerFilter = opt_layerFilter !== undefined ?
       opt_layerFilter : goog.functions.TRUE;
-  var thisArg2 = goog.isDef(opt_this2) ? opt_this2 : null;
+  var thisArg2 = opt_this2 !== undefined ? opt_this2 : null;
   return this.renderer_.forEachFeatureAtCoordinate(
       coordinate, this.frameState_, callback, thisArg,
       layerFilter, thisArg2);
@@ -637,10 +637,10 @@ ol.Map.prototype.forEachLayerAtPixel =
   if (goog.isNull(this.frameState_)) {
     return;
   }
-  var thisArg = goog.isDef(opt_this) ? opt_this : null;
-  var layerFilter = goog.isDef(opt_layerFilter) ?
+  var thisArg = opt_this !== undefined ? opt_this : null;
+  var layerFilter = opt_layerFilter !== undefined ?
       opt_layerFilter : goog.functions.TRUE;
-  var thisArg2 = goog.isDef(opt_this2) ? opt_this2 : null;
+  var thisArg2 = opt_this2 !== undefined ? opt_this2 : null;
   return this.renderer_.forEachLayerAtPixel(
       pixel, this.frameState_, callback, thisArg,
       layerFilter, thisArg2);
@@ -668,9 +668,9 @@ ol.Map.prototype.hasFeatureAtPixel =
     return false;
   }
   var coordinate = this.getCoordinateFromPixel(pixel);
-  var layerFilter = goog.isDef(opt_layerFilter) ?
+  var layerFilter = opt_layerFilter !== undefined ?
       opt_layerFilter : goog.functions.TRUE;
-  var thisArg = goog.isDef(opt_this) ? opt_this : null;
+  var thisArg = opt_this !== undefined ? opt_this : null;
   return this.renderer_.hasFeatureAtCoordinate(
       coordinate, this.frameState_, layerFilter, thisArg);
 };
@@ -723,7 +723,7 @@ ol.Map.prototype.getTarget = function() {
  */
 ol.Map.prototype.getTargetElement = function() {
   var target = this.getTarget();
-  return goog.isDef(target) ? goog.dom.getElement(target) : null;
+  return target !== undefined ? goog.dom.getElement(target) : null;
 };
 
 
@@ -941,7 +941,7 @@ ol.Map.prototype.handleMapBrowserEvent = function(mapBrowserEvent) {
   this.focus_ = mapBrowserEvent.coordinate;
   mapBrowserEvent.frameState = this.frameState_;
   var interactions = this.getInteractions();
-  goog.asserts.assert(goog.isDef(interactions),
+  goog.asserts.assert(interactions !== undefined,
       'interactions should be defined');
   var interactionsArray = interactions.getArray();
   var i;
@@ -1199,7 +1199,7 @@ ol.Map.prototype.render = function() {
  */
 ol.Map.prototype.removeControl = function(control) {
   var controls = this.getControls();
-  goog.asserts.assert(goog.isDef(controls), 'controls should be defined');
+  goog.asserts.assert(controls !== undefined, 'controls should be defined');
   if (goog.isDef(controls.remove(control))) {
     return control;
   }
@@ -1217,7 +1217,7 @@ ol.Map.prototype.removeControl = function(control) {
 ol.Map.prototype.removeInteraction = function(interaction) {
   var removed;
   var interactions = this.getInteractions();
-  goog.asserts.assert(goog.isDef(interactions),
+  goog.asserts.assert(interactions !== undefined,
       'interactions should be defined');
   if (goog.isDef(interactions.remove(interaction))) {
     removed = interaction;
@@ -1248,7 +1248,7 @@ ol.Map.prototype.removeLayer = function(layer) {
  */
 ol.Map.prototype.removeOverlay = function(overlay) {
   var overlays = this.getOverlays();
-  goog.asserts.assert(goog.isDef(overlays), 'overlays should be defined');
+  goog.asserts.assert(overlays !== undefined, 'overlays should be defined');
   if (goog.isDef(overlays.remove(overlay))) {
     return overlay;
   }
@@ -1268,7 +1268,7 @@ ol.Map.prototype.renderFrame_ = function(time) {
   var view = this.getView();
   /** @type {?olx.FrameState} */
   var frameState = null;
-  if (goog.isDef(size) && ol.size.hasArea(size) &&
+  if (size !== undefined && ol.size.hasArea(size) &&
       !goog.isNull(view) && view.isDef()) {
     var viewHints = view.getHints();
     var layerStatesArray = this.getLayerGroup().getLayerStatesArray();
diff --git a/src/ol/mapbrowserevent.js b/src/ol/mapbrowserevent.js
index 32baec1783..ccfad65fad 100644
--- a/src/ol/mapbrowserevent.js
+++ b/src/ol/mapbrowserevent.js
@@ -73,7 +73,7 @@ ol.MapBrowserEvent = function(type, map, browserEvent, opt_dragging,
    * @type {boolean}
    * @api stable
    */
-  this.dragging = goog.isDef(opt_dragging) ? opt_dragging : false;
+  this.dragging = opt_dragging !== undefined ? opt_dragging : false;
 
 };
 goog.inherits(ol.MapBrowserEvent, ol.MapEvent);
diff --git a/src/ol/mapevent.js b/src/ol/mapevent.js
index 909a774f23..dd37dc2505 100644
--- a/src/ol/mapevent.js
+++ b/src/ol/mapevent.js
@@ -55,7 +55,7 @@ ol.MapEvent = function(type, map, opt_frameState) {
    * @type {?olx.FrameState}
    * @api
    */
-  this.frameState = goog.isDef(opt_frameState) ? opt_frameState : null;
+  this.frameState = opt_frameState !== undefined ? opt_frameState : null;
 
 };
 goog.inherits(ol.MapEvent, goog.events.Event);
diff --git a/src/ol/overlay.js b/src/ol/overlay.js
index 71b3f649d8..97950b21c3 100644
--- a/src/ol/overlay.js
+++ b/src/ol/overlay.js
@@ -403,7 +403,7 @@ ol.Overlay.prototype.panIntoView_ = function() {
 
     if (delta[0] !== 0 || delta[1] !== 0) {
       var center = map.getView().getCenter();
-      goog.asserts.assert(goog.isDef(center), 'center should be defined');
+      goog.asserts.assert(center !== undefined, 'center should be defined');
       var centerPx = map.getPixelFromCoordinate(center);
       var newCenterPx = [
         centerPx[0] + delta[0],
@@ -430,7 +430,7 @@ ol.Overlay.prototype.panIntoView_ = function() {
 ol.Overlay.prototype.getRect_ = function(element, size) {
   goog.asserts.assert(goog.isDefAndNotNull(element),
       'element should be defined');
-  goog.asserts.assert(goog.isDef(size), 'size should be defined');
+  goog.asserts.assert(size !== undefined, 'size should be defined');
 
   var offset = goog.style.getPageOffset(element);
   return [
@@ -492,13 +492,13 @@ ol.Overlay.prototype.updatePixelPosition = function() {
  */
 ol.Overlay.prototype.updateRenderedPosition = function(pixel, mapSize) {
   goog.asserts.assert(!goog.isNull(pixel), 'pixel should not be null');
-  goog.asserts.assert(goog.isDef(mapSize), 'mapSize should be defined');
+  goog.asserts.assert(mapSize !== undefined, 'mapSize should be defined');
   var style = this.element_.style;
   var offset = this.getOffset();
   goog.asserts.assert(goog.isArray(offset), 'offset should be an array');
 
   var positioning = this.getPositioning();
-  goog.asserts.assert(goog.isDef(positioning),
+  goog.asserts.assert(positioning !== undefined,
       'positioning should be defined');
 
   var offsetX = offset[0];
diff --git a/src/ol/proj/proj.js b/src/ol/proj/proj.js
index 27d0f42873..a909eba5c0 100644
--- a/src/ol/proj/proj.js
+++ b/src/ol/proj/proj.js
@@ -143,7 +143,7 @@ ol.proj.Projection = function(options) {
 
   var projections = ol.proj.projections_;
   var code = options.code;
-  goog.asserts.assert(goog.isDef(code),
+  goog.asserts.assert(code !== undefined,
       'Option "code" is required for constructing instance');
   if (ol.ENABLE_PROJ4JS && typeof proj4 == 'function' &&
       !goog.isDef(projections[code])) {
@@ -563,8 +563,8 @@ ol.proj.createTransformFromCoordinateTransform = function(transform) {
        */
       function(input, opt_output, opt_dimension) {
         var length = input.length;
-        var dimension = goog.isDef(opt_dimension) ? opt_dimension : 2;
-        var output = goog.isDef(opt_output) ? opt_output : new Array(length);
+        var dimension = opt_dimension !== undefined ? opt_dimension : 2;
+        var output = opt_output !== undefined ? opt_output : new Array(length);
         var point, i, j;
         for (i = 0; i < length; i += dimension) {
           point = transform([input[i], input[i + 1]]);
@@ -617,7 +617,7 @@ ol.proj.removeTransform = function(source, destination) {
  */
 ol.proj.fromLonLat = function(coordinate, opt_projection) {
   return ol.proj.transform(coordinate, 'EPSG:4326',
-      goog.isDef(opt_projection) ? opt_projection : 'EPSG:3857');
+      opt_projection !== undefined ? opt_projection : 'EPSG:3857');
 };
 
 
@@ -632,7 +632,7 @@ ol.proj.fromLonLat = function(coordinate, opt_projection) {
  */
 ol.proj.toLonLat = function(coordinate, opt_projection) {
   return ol.proj.transform(coordinate,
-      goog.isDef(opt_projection) ? opt_projection : 'EPSG:3857', 'EPSG:4326');
+      opt_projection !== undefined ? opt_projection : 'EPSG:3857', 'EPSG:4326');
 };
 
 
@@ -726,7 +726,7 @@ ol.proj.getTransformFromProjections =
     transform = transforms[sourceCode][destinationCode];
   }
   if (transform === undefined) {
-    goog.asserts.assert(goog.isDef(transform), 'transform should be defined');
+    goog.asserts.assert(transform !== undefined, 'transform should be defined');
     transform = ol.proj.identityTransform;
   }
   return transform;
@@ -740,7 +740,7 @@ ol.proj.getTransformFromProjections =
  * @return {Array.<number>} Input coordinate array (same array as input).
  */
 ol.proj.identityTransform = function(input, opt_output, opt_dimension) {
-  if (goog.isDef(opt_output) && input !== opt_output) {
+  if (opt_output !== undefined && input !== opt_output) {
     // TODO: consider making this a warning instead
     goog.asserts.fail('This should not be used internally.');
     for (var i = 0, ii = input.length; i < ii; ++i) {
diff --git a/src/ol/render/canvas/canvasimmediate.js b/src/ol/render/canvas/canvasimmediate.js
index 368f1ce525..85e5f65673 100644
--- a/src/ol/render/canvas/canvasimmediate.js
+++ b/src/ol/render/canvas/canvasimmediate.js
@@ -494,7 +494,7 @@ ol.render.canvas.Immediate.prototype.drawFeature = function(feature, style) {
     render.setTextStyle(style.getText());
     var renderGeometry =
         ol.render.canvas.Immediate.GEOMETRY_RENDERERS_[geometry.getType()];
-    goog.asserts.assert(goog.isDef(renderGeometry),
+    goog.asserts.assert(renderGeometry !== undefined,
         'renderGeometry should be defined');
     renderGeometry.call(render, geometry, null);
   });
@@ -517,7 +517,7 @@ ol.render.canvas.Immediate.prototype.drawGeometryCollectionGeometry =
     var geometry = geometries[i];
     var geometryRenderer =
         ol.render.canvas.Immediate.GEOMETRY_RENDERERS_[geometry.getType()];
-    goog.asserts.assert(goog.isDef(geometryRenderer),
+    goog.asserts.assert(geometryRenderer !== undefined,
         'geometryRenderer should be defined');
     geometryRenderer.call(this, geometry, feature);
   }
@@ -872,15 +872,15 @@ ol.render.canvas.Immediate.prototype.setFillStrokeStyle =
     var strokeStyleWidth = strokeStyle.getWidth();
     var strokeStyleMiterLimit = strokeStyle.getMiterLimit();
     this.strokeState_ = {
-      lineCap: goog.isDef(strokeStyleLineCap) ?
+      lineCap: strokeStyleLineCap !== undefined ?
           strokeStyleLineCap : ol.render.canvas.defaultLineCap,
       lineDash: goog.isDefAndNotNull(strokeStyleLineDash) ?
           strokeStyleLineDash : ol.render.canvas.defaultLineDash,
-      lineJoin: goog.isDef(strokeStyleLineJoin) ?
+      lineJoin: strokeStyleLineJoin !== undefined ?
           strokeStyleLineJoin : ol.render.canvas.defaultLineJoin,
-      lineWidth: this.pixelRatio_ * (goog.isDef(strokeStyleWidth) ?
+      lineWidth: this.pixelRatio_ * (strokeStyleWidth !== undefined ?
           strokeStyleWidth : ol.render.canvas.defaultLineWidth),
-      miterLimit: goog.isDef(strokeStyleMiterLimit) ?
+      miterLimit: strokeStyleMiterLimit !== undefined ?
           strokeStyleMiterLimit : ol.render.canvas.defaultMiterLimit,
       strokeStyle: ol.color.asString(!goog.isNull(strokeStyleColor) ?
           strokeStyleColor : ol.render.canvas.defaultStrokeStyle)
@@ -961,15 +961,15 @@ ol.render.canvas.Immediate.prototype.setTextStyle = function(textStyle) {
       var textStrokeStyleWidth = textStrokeStyle.getWidth();
       var textStrokeStyleMiterLimit = textStrokeStyle.getMiterLimit();
       this.textStrokeState_ = {
-        lineCap: goog.isDef(textStrokeStyleLineCap) ?
+        lineCap: textStrokeStyleLineCap !== undefined ?
             textStrokeStyleLineCap : ol.render.canvas.defaultLineCap,
         lineDash: goog.isDefAndNotNull(textStrokeStyleLineDash) ?
             textStrokeStyleLineDash : ol.render.canvas.defaultLineDash,
-        lineJoin: goog.isDef(textStrokeStyleLineJoin) ?
+        lineJoin: textStrokeStyleLineJoin !== undefined ?
             textStrokeStyleLineJoin : ol.render.canvas.defaultLineJoin,
-        lineWidth: goog.isDef(textStrokeStyleWidth) ?
+        lineWidth: textStrokeStyleWidth !== undefined ?
             textStrokeStyleWidth : ol.render.canvas.defaultLineWidth,
-        miterLimit: goog.isDef(textStrokeStyleMiterLimit) ?
+        miterLimit: textStrokeStyleMiterLimit !== undefined ?
             textStrokeStyleMiterLimit : ol.render.canvas.defaultMiterLimit,
         strokeStyle: ol.color.asString(!goog.isNull(textStrokeStyleColor) ?
             textStrokeStyleColor : ol.render.canvas.defaultStrokeStyle)
@@ -984,20 +984,20 @@ ol.render.canvas.Immediate.prototype.setTextStyle = function(textStyle) {
     var textTextAlign = textStyle.getTextAlign();
     var textTextBaseline = textStyle.getTextBaseline();
     this.textState_ = {
-      font: goog.isDef(textFont) ?
+      font: textFont !== undefined ?
           textFont : ol.render.canvas.defaultFont,
-      textAlign: goog.isDef(textTextAlign) ?
+      textAlign: textTextAlign !== undefined ?
           textTextAlign : ol.render.canvas.defaultTextAlign,
-      textBaseline: goog.isDef(textTextBaseline) ?
+      textBaseline: textTextBaseline !== undefined ?
           textTextBaseline : ol.render.canvas.defaultTextBaseline
     };
-    this.text_ = goog.isDef(textText) ? textText : '';
+    this.text_ = textText !== undefined ? textText : '';
     this.textOffsetX_ =
-        goog.isDef(textOffsetX) ? (this.pixelRatio_ * textOffsetX) : 0;
+        textOffsetX !== undefined ? (this.pixelRatio_ * textOffsetX) : 0;
     this.textOffsetY_ =
-        goog.isDef(textOffsetY) ? (this.pixelRatio_ * textOffsetY) : 0;
-    this.textRotation_ = goog.isDef(textRotation) ? textRotation : 0;
-    this.textScale_ = this.pixelRatio_ * (goog.isDef(textScale) ?
+        textOffsetY !== undefined ? (this.pixelRatio_ * textOffsetY) : 0;
+    this.textRotation_ = textRotation !== undefined ? textRotation : 0;
+    this.textScale_ = this.pixelRatio_ * (textScale !== undefined ?
         textScale : 1);
   }
 };
diff --git a/src/ol/render/canvas/canvasreplay.js b/src/ol/render/canvas/canvasreplay.js
index 8de2dbecb3..8e33020d22 100644
--- a/src/ol/render/canvas/canvasreplay.js
+++ b/src/ol/render/canvas/canvasreplay.js
@@ -260,7 +260,7 @@ ol.render.canvas.Replay.prototype.replay_ = function(
         if (goog.isDef(skippedFeaturesHash[featureUid]) ||
             !goog.isDefAndNotNull(feature.getGeometry())) {
           i = /** @type {number} */ (instruction[2]);
-        } else if (goog.isDef(opt_hitExtent) && !ol.extent.intersects(
+        } else if (opt_hitExtent !== undefined && !ol.extent.intersects(
             opt_hitExtent, feature.getGeometry().getExtent())) {
           i = /** @type {number} */ (instruction[2]);
         } else {
@@ -966,13 +966,13 @@ ol.render.canvas.LineStringReplay.prototype.setStrokeStyle_ = function() {
   var lineJoin = state.lineJoin;
   var lineWidth = state.lineWidth;
   var miterLimit = state.miterLimit;
-  goog.asserts.assert(goog.isDef(strokeStyle),
+  goog.asserts.assert(strokeStyle !== undefined,
       'strokeStyle should be defined');
-  goog.asserts.assert(goog.isDef(lineCap), 'lineCap should be defined');
+  goog.asserts.assert(lineCap !== undefined, 'lineCap should be defined');
   goog.asserts.assert(!goog.isNull(lineDash), 'lineDash should not be null');
-  goog.asserts.assert(goog.isDef(lineJoin), 'lineJoin should be defined');
-  goog.asserts.assert(goog.isDef(lineWidth), 'lineWidth should be defined');
-  goog.asserts.assert(goog.isDef(miterLimit), 'miterLimit should be defined');
+  goog.asserts.assert(lineJoin !== undefined, 'lineJoin should be defined');
+  goog.asserts.assert(lineWidth !== undefined, 'lineWidth should be defined');
+  goog.asserts.assert(miterLimit !== undefined, 'miterLimit should be defined');
   if (state.currentStrokeStyle != strokeStyle ||
       state.currentLineCap != lineCap ||
       !goog.array.equals(state.currentLineDash, lineDash) ||
@@ -1087,19 +1087,19 @@ ol.render.canvas.LineStringReplay.prototype.setFillStrokeStyle =
   this.state_.strokeStyle = ol.color.asString(!goog.isNull(strokeStyleColor) ?
       strokeStyleColor : ol.render.canvas.defaultStrokeStyle);
   var strokeStyleLineCap = strokeStyle.getLineCap();
-  this.state_.lineCap = goog.isDef(strokeStyleLineCap) ?
+  this.state_.lineCap = strokeStyleLineCap !== undefined ?
       strokeStyleLineCap : ol.render.canvas.defaultLineCap;
   var strokeStyleLineDash = strokeStyle.getLineDash();
   this.state_.lineDash = !goog.isNull(strokeStyleLineDash) ?
       strokeStyleLineDash : ol.render.canvas.defaultLineDash;
   var strokeStyleLineJoin = strokeStyle.getLineJoin();
-  this.state_.lineJoin = goog.isDef(strokeStyleLineJoin) ?
+  this.state_.lineJoin = strokeStyleLineJoin !== undefined ?
       strokeStyleLineJoin : ol.render.canvas.defaultLineJoin;
   var strokeStyleWidth = strokeStyle.getWidth();
-  this.state_.lineWidth = goog.isDef(strokeStyleWidth) ?
+  this.state_.lineWidth = strokeStyleWidth !== undefined ?
       strokeStyleWidth : ol.render.canvas.defaultLineWidth;
   var strokeStyleMiterLimit = strokeStyle.getMiterLimit();
-  this.state_.miterLimit = goog.isDef(strokeStyleMiterLimit) ?
+  this.state_.miterLimit = strokeStyleMiterLimit !== undefined ?
       strokeStyleMiterLimit : ol.render.canvas.defaultMiterLimit;
 
   if (this.state_.lineWidth > this.maxLineWidth) {
@@ -1398,19 +1398,19 @@ ol.render.canvas.PolygonReplay.prototype.setFillStrokeStyle =
     state.strokeStyle = ol.color.asString(!goog.isNull(strokeStyleColor) ?
         strokeStyleColor : ol.render.canvas.defaultStrokeStyle);
     var strokeStyleLineCap = strokeStyle.getLineCap();
-    state.lineCap = goog.isDef(strokeStyleLineCap) ?
+    state.lineCap = strokeStyleLineCap !== undefined ?
         strokeStyleLineCap : ol.render.canvas.defaultLineCap;
     var strokeStyleLineDash = strokeStyle.getLineDash();
     state.lineDash = !goog.isNull(strokeStyleLineDash) ?
         strokeStyleLineDash.slice() : ol.render.canvas.defaultLineDash;
     var strokeStyleLineJoin = strokeStyle.getLineJoin();
-    state.lineJoin = goog.isDef(strokeStyleLineJoin) ?
+    state.lineJoin = strokeStyleLineJoin !== undefined ?
         strokeStyleLineJoin : ol.render.canvas.defaultLineJoin;
     var strokeStyleWidth = strokeStyle.getWidth();
-    state.lineWidth = goog.isDef(strokeStyleWidth) ?
+    state.lineWidth = strokeStyleWidth !== undefined ?
         strokeStyleWidth : ol.render.canvas.defaultLineWidth;
     var strokeStyleMiterLimit = strokeStyle.getMiterLimit();
-    state.miterLimit = goog.isDef(strokeStyleMiterLimit) ?
+    state.miterLimit = strokeStyleMiterLimit !== undefined ?
         strokeStyleMiterLimit : ol.render.canvas.defaultMiterLimit;
 
     if (state.lineWidth > this.maxLineWidth) {
@@ -1441,17 +1441,18 @@ ol.render.canvas.PolygonReplay.prototype.setFillStrokeStyles_ = function() {
   var lineJoin = state.lineJoin;
   var lineWidth = state.lineWidth;
   var miterLimit = state.miterLimit;
-  if (goog.isDef(fillStyle) && state.currentFillStyle != fillStyle) {
+  if (fillStyle !== undefined && state.currentFillStyle != fillStyle) {
     this.instructions.push(
         [ol.render.canvas.Instruction.SET_FILL_STYLE, fillStyle]);
     state.currentFillStyle = state.fillStyle;
   }
   if (strokeStyle !== undefined) {
-    goog.asserts.assert(goog.isDef(lineCap), 'lineCap should be defined');
+    goog.asserts.assert(lineCap !== undefined, 'lineCap should be defined');
     goog.asserts.assert(!goog.isNull(lineDash), 'lineDash should not be null');
-    goog.asserts.assert(goog.isDef(lineJoin), 'lineJoin should be defined');
-    goog.asserts.assert(goog.isDef(lineWidth), 'lineWidth should be defined');
-    goog.asserts.assert(goog.isDef(miterLimit), 'miterLimit should be defined');
+    goog.asserts.assert(lineJoin !== undefined, 'lineJoin should be defined');
+    goog.asserts.assert(lineWidth !== undefined, 'lineWidth should be defined');
+    goog.asserts.assert(miterLimit !== undefined,
+        'miterLimit should be defined');
     if (state.currentStrokeStyle != strokeStyle ||
         state.currentLineCap != lineCap ||
         state.currentLineDash != lineDash ||
@@ -1722,15 +1723,15 @@ ol.render.canvas.TextReplay.prototype.setTextStyle = function(textStyle) {
       var textStrokeStyleLineJoin = textStrokeStyle.getLineJoin();
       var textStrokeStyleWidth = textStrokeStyle.getWidth();
       var textStrokeStyleMiterLimit = textStrokeStyle.getMiterLimit();
-      var lineCap = goog.isDef(textStrokeStyleLineCap) ?
+      var lineCap = textStrokeStyleLineCap !== undefined ?
           textStrokeStyleLineCap : ol.render.canvas.defaultLineCap;
       var lineDash = goog.isDefAndNotNull(textStrokeStyleLineDash) ?
           textStrokeStyleLineDash.slice() : ol.render.canvas.defaultLineDash;
-      var lineJoin = goog.isDef(textStrokeStyleLineJoin) ?
+      var lineJoin = textStrokeStyleLineJoin !== undefined ?
           textStrokeStyleLineJoin : ol.render.canvas.defaultLineJoin;
-      var lineWidth = goog.isDef(textStrokeStyleWidth) ?
+      var lineWidth = textStrokeStyleWidth !== undefined ?
           textStrokeStyleWidth : ol.render.canvas.defaultLineWidth;
-      var miterLimit = goog.isDef(textStrokeStyleMiterLimit) ?
+      var miterLimit = textStrokeStyleMiterLimit !== undefined ?
           textStrokeStyleMiterLimit : ol.render.canvas.defaultMiterLimit;
       var strokeStyle = ol.color.asString(!goog.isNull(textStrokeStyleColor) ?
           textStrokeStyleColor : ol.render.canvas.defaultStrokeStyle);
@@ -1761,11 +1762,11 @@ ol.render.canvas.TextReplay.prototype.setTextStyle = function(textStyle) {
     var textText = textStyle.getText();
     var textTextAlign = textStyle.getTextAlign();
     var textTextBaseline = textStyle.getTextBaseline();
-    var font = goog.isDef(textFont) ?
+    var font = textFont !== undefined ?
         textFont : ol.render.canvas.defaultFont;
-    var textAlign = goog.isDef(textTextAlign) ?
+    var textAlign = textTextAlign !== undefined ?
         textTextAlign : ol.render.canvas.defaultTextAlign;
-    var textBaseline = goog.isDef(textTextBaseline) ?
+    var textBaseline = textTextBaseline !== undefined ?
         textTextBaseline : ol.render.canvas.defaultTextBaseline;
     if (goog.isNull(this.textState_)) {
       this.textState_ = {
@@ -1779,11 +1780,11 @@ ol.render.canvas.TextReplay.prototype.setTextStyle = function(textStyle) {
       textState.textAlign = textAlign;
       textState.textBaseline = textBaseline;
     }
-    this.text_ = goog.isDef(textText) ? textText : '';
-    this.textOffsetX_ = goog.isDef(textOffsetX) ? textOffsetX : 0;
-    this.textOffsetY_ = goog.isDef(textOffsetY) ? textOffsetY : 0;
-    this.textRotation_ = goog.isDef(textRotation) ? textRotation : 0;
-    this.textScale_ = goog.isDef(textScale) ? textScale : 1;
+    this.text_ = textText !== undefined ? textText : '';
+    this.textOffsetX_ = textOffsetX !== undefined ? textOffsetX : 0;
+    this.textOffsetY_ = textOffsetY !== undefined ? textOffsetY : 0;
+    this.textRotation_ = textRotation !== undefined ? textRotation : 0;
+    this.textScale_ = textScale !== undefined ? textScale : 1;
   }
 };
 
@@ -1917,7 +1918,7 @@ ol.render.canvas.ReplayGroup.prototype.forEachFeatureAtCoordinate = function(
  */
 ol.render.canvas.ReplayGroup.prototype.getReplay =
     function(zIndex, replayType) {
-  var zIndexKey = goog.isDef(zIndex) ? zIndex.toString() : '0';
+  var zIndexKey = zIndex !== undefined ? zIndex.toString() : '0';
   var replays = this.replaysByZIndex_[zIndexKey];
   if (replays === undefined) {
     replays = {};
@@ -1926,7 +1927,7 @@ ol.render.canvas.ReplayGroup.prototype.getReplay =
   var replay = replays[replayType];
   if (replay === undefined) {
     var Constructor = ol.render.canvas.BATCH_CONSTRUCTORS_[replayType];
-    goog.asserts.assert(goog.isDef(Constructor),
+    goog.asserts.assert(Constructor !== undefined,
         replayType +
         ' constructor missing from ol.render.canvas.BATCH_CONSTRUCTORS_');
     replay = new Constructor(this.tolerance_, this.maxExtent_,
diff --git a/src/ol/render/webgl/webglreplay.js b/src/ol/render/webgl/webglreplay.js
index 9508c34470..bb9e91f52b 100644
--- a/src/ol/render/webgl/webglreplay.js
+++ b/src/ol/render/webgl/webglreplay.js
@@ -914,13 +914,13 @@ ol.render.webgl.ImageReplay.prototype.setImageStyle = function(imageStyle) {
       'imageStyle hitDetectionImage is not null');
   goog.asserts.assert(!goog.isNull(hitDetectionImageSize),
       'imageStyle hitDetectionImageSize is not null');
-  goog.asserts.assert(goog.isDef(opacity), 'imageStyle opacity is defined');
+  goog.asserts.assert(opacity !== undefined, 'imageStyle opacity is defined');
   goog.asserts.assert(!goog.isNull(origin), 'imageStyle origin is not null');
-  goog.asserts.assert(goog.isDef(rotateWithView),
+  goog.asserts.assert(rotateWithView !== undefined,
       'imageStyle rotateWithView is defined');
-  goog.asserts.assert(goog.isDef(rotation), 'imageStyle rotation is defined');
+  goog.asserts.assert(rotation !== undefined, 'imageStyle rotation is defined');
   goog.asserts.assert(!goog.isNull(size), 'imageStyle size is not null');
-  goog.asserts.assert(goog.isDef(scale), 'imageStyle scale is defined');
+  goog.asserts.assert(scale !== undefined, 'imageStyle scale is defined');
 
   var currentImage;
   if (this.images_.length === 0) {
@@ -1039,7 +1039,7 @@ ol.render.webgl.ReplayGroup.prototype.getReplay =
   var replay = this.replays_[replayType];
   if (replay === undefined) {
     var constructor = ol.render.webgl.BATCH_CONSTRUCTORS_[replayType];
-    goog.asserts.assert(goog.isDef(constructor),
+    goog.asserts.assert(constructor !== undefined,
         replayType +
         ' constructor missing from ol.render.webgl.BATCH_CONSTRUCTORS_');
     replay = new constructor(this.tolerance_, this.maxExtent_);
@@ -1231,7 +1231,7 @@ ol.render.webgl.ReplayGroup.prototype.hasFeatureAtCoordinate = function(
         return imageData[3] > 0;
       }, false);
 
-  return goog.isDef(hasFeature);
+  return hasFeature !== undefined;
 };
 
 
diff --git a/src/ol/renderer/canvas/canvaslayerrenderer.js b/src/ol/renderer/canvas/canvaslayerrenderer.js
index 7e85d22355..b011d30222 100644
--- a/src/ol/renderer/canvas/canvaslayerrenderer.js
+++ b/src/ol/renderer/canvas/canvaslayerrenderer.js
@@ -48,9 +48,9 @@ ol.renderer.canvas.Layer.prototype.composeFrame =
 
     // clipped rendering if layer extent is set
     var extent = layerState.extent;
-    var clipped = goog.isDef(extent);
+    var clipped = extent !== undefined;
     if (clipped) {
-      goog.asserts.assert(goog.isDef(extent),
+      goog.asserts.assert(extent !== undefined,
           'layerState extent is defined');
       var pixelRatio = frameState.pixelRatio;
       var topLeft = ol.extent.getTopLeft(extent);
@@ -126,7 +126,7 @@ ol.renderer.canvas.Layer.prototype.dispatchComposeEvent_ =
     function(type, context, frameState, opt_transform) {
   var layer = this.getLayer();
   if (layer.hasListener(type)) {
-    var transform = goog.isDef(opt_transform) ?
+    var transform = opt_transform !== undefined ?
         opt_transform : this.getTransform(frameState, 0);
     var render = new ol.render.canvas.Immediate(
         context, frameState.pixelRatio, frameState.extent, transform,
diff --git a/src/ol/renderer/canvas/canvasvectorlayerrenderer.js b/src/ol/renderer/canvas/canvasvectorlayerrenderer.js
index de3fc32f5d..6c55c66bbd 100644
--- a/src/ol/renderer/canvas/canvasvectorlayerrenderer.js
+++ b/src/ol/renderer/canvas/canvasvectorlayerrenderer.js
@@ -172,7 +172,7 @@ ol.renderer.canvas.VectorLayer.prototype.forEachFeatureAtCoordinate =
          * @return {?} Callback result.
          */
         function(feature) {
-          goog.asserts.assert(goog.isDef(feature), 'received a feature');
+          goog.asserts.assert(feature !== undefined, 'received a feature');
           var key = goog.getUid(feature).toString();
           if (!(key in features)) {
             features[key] = true;
diff --git a/src/ol/renderer/dom/domvectorlayerrenderer.js b/src/ol/renderer/dom/domvectorlayerrenderer.js
index fbddccba80..65603d5586 100644
--- a/src/ol/renderer/dom/domvectorlayerrenderer.js
+++ b/src/ol/renderer/dom/domvectorlayerrenderer.js
@@ -194,7 +194,7 @@ ol.renderer.dom.VectorLayer.prototype.forEachFeatureAtCoordinate =
          * @return {?} Callback result.
          */
         function(feature) {
-          goog.asserts.assert(goog.isDef(feature), 'received a feature');
+          goog.asserts.assert(feature !== undefined, 'received a feature');
           var key = goog.getUid(feature).toString();
           if (!(key in features)) {
             features[key] = true;
diff --git a/src/ol/renderer/webgl/webglimagelayerrenderer.js b/src/ol/renderer/webgl/webglimagelayerrenderer.js
index dd0db38c27..8f8964d65e 100644
--- a/src/ol/renderer/webgl/webglimagelayerrenderer.js
+++ b/src/ol/renderer/webgl/webglimagelayerrenderer.js
@@ -225,7 +225,7 @@ ol.renderer.webgl.ImageLayer.prototype.hasFeatureAtCoordinate =
     function(coordinate, frameState) {
   var hasFeature = this.forEachFeatureAtCoordinate(
       coordinate, frameState, goog.functions.TRUE, this);
-  return goog.isDef(hasFeature);
+  return hasFeature !== undefined;
 };
 
 
diff --git a/src/ol/renderer/webgl/webglvectorlayerrenderer.js b/src/ol/renderer/webgl/webglvectorlayerrenderer.js
index 023b0849e0..4d5a28f72b 100644
--- a/src/ol/renderer/webgl/webglvectorlayerrenderer.js
+++ b/src/ol/renderer/webgl/webglvectorlayerrenderer.js
@@ -129,7 +129,7 @@ ol.renderer.webgl.VectorLayer.prototype.forEachFeatureAtCoordinate =
          * @return {?} Callback result.
          */
         function(feature) {
-          goog.asserts.assert(goog.isDef(feature), 'received a feature');
+          goog.asserts.assert(feature !== undefined, 'received a feature');
           var key = goog.getUid(feature).toString();
           if (!(key in features)) {
             features[key] = true;
diff --git a/src/ol/source/imagevectorsource.js b/src/ol/source/imagevectorsource.js
index 1e745005c7..f1dd179192 100644
--- a/src/ol/source/imagevectorsource.js
+++ b/src/ol/source/imagevectorsource.js
@@ -166,7 +166,7 @@ ol.source.ImageVector.prototype.forEachFeatureAtCoordinate = function(
          * @return {?} Callback result.
          */
         function(feature) {
-          goog.asserts.assert(goog.isDef(feature), 'passed a feature');
+          goog.asserts.assert(feature !== undefined, 'passed a feature');
           var key = goog.getUid(feature).toString();
           if (!(key in features)) {
             features[key] = true;
@@ -290,7 +290,7 @@ ol.source.ImageVector.prototype.renderFeature_ =
  * @api stable
  */
 ol.source.ImageVector.prototype.setStyle = function(style) {
-  this.style_ = goog.isDef(style) ? style : ol.style.defaultStyleFunction;
+  this.style_ = style !== undefined ? style : ol.style.defaultStyleFunction;
   this.styleFunction_ = goog.isNull(style) ?
       undefined : ol.style.createStyleFunction(this.style_);
   this.changed();
diff --git a/src/ol/source/tilearcgisrestsource.js b/src/ol/source/tilearcgisrestsource.js
index e1093f1006..29c7e19d22 100644
--- a/src/ol/source/tilearcgisrestsource.js
+++ b/src/ol/source/tilearcgisrestsource.js
@@ -173,7 +173,7 @@ ol.source.TileArcGISRest.prototype.getUrls = function() {
  * @api stable
  */
 ol.source.TileArcGISRest.prototype.setUrl = function(url) {
-  var urls = goog.isDef(url) ? ol.TileUrlFunction.expandUrl(url) : null;
+  var urls = url !== undefined ? ol.TileUrlFunction.expandUrl(url) : null;
   this.setUrls(urls);
 };
 
diff --git a/src/ol/source/tiledebugsource.js b/src/ol/source/tiledebugsource.js
index 01d884bb8f..66b7409fbd 100644
--- a/src/ol/source/tiledebugsource.js
+++ b/src/ol/source/tiledebugsource.js
@@ -48,7 +48,7 @@ goog.inherits(ol.DebugTile_, ol.Tile);
  * @inheritDoc
  */
 ol.DebugTile_.prototype.getImage = function(opt_context) {
-  var key = goog.isDef(opt_context) ? goog.getUid(opt_context) : -1;
+  var key = opt_context !== undefined ? goog.getUid(opt_context) : -1;
   if (key in this.canvasByContext_) {
     return this.canvasByContext_[key];
   } else {
diff --git a/src/ol/source/tileimagesource.js b/src/ol/source/tileimagesource.js
index 1701f19e86..457143f702 100644
--- a/src/ol/source/tileimagesource.js
+++ b/src/ol/source/tileimagesource.js
@@ -99,8 +99,8 @@ ol.source.TileImage.prototype.getTile =
         this.tileUrlFunction(urlTileCoord, pixelRatio, projection);
     var tile = new this.tileClass(
         tileCoord,
-        goog.isDef(tileUrl) ? ol.TileState.IDLE : ol.TileState.EMPTY,
-        goog.isDef(tileUrl) ? tileUrl : '',
+        tileUrl !== undefined ? ol.TileState.IDLE : ol.TileState.EMPTY,
+        tileUrl !== undefined ? tileUrl : '',
         this.crossOrigin,
         this.tileLoadFunction);
     goog.events.listen(tile, goog.events.EventType.CHANGE,
diff --git a/src/ol/source/tilejsonsource.js b/src/ol/source/tilejsonsource.js
index 18282462db..472cfbd181 100644
--- a/src/ol/source/tilejsonsource.js
+++ b/src/ol/source/tilejsonsource.js
@@ -79,7 +79,7 @@ ol.source.TileJSON.prototype.handleTileJSONResponse = function(tileJSON) {
 
   if (goog.isDef(tileJSON.attribution) &&
       goog.isNull(this.getAttributions())) {
-    var attributionExtent = goog.isDef(extent) ?
+    var attributionExtent = extent !== undefined ?
         extent : epsg4326Projection.getExtent();
     /** @type {Object.<string, Array.<ol.TileRange>>} */
     var tileRanges = {};
diff --git a/src/ol/source/tilesource.js b/src/ol/source/tilesource.js
index 4384434899..b0546ecaaa 100644
--- a/src/ol/source/tilesource.js
+++ b/src/ol/source/tilesource.js
@@ -227,7 +227,7 @@ ol.source.Tile.prototype.getTilePixelSize =
  */
 ol.source.Tile.prototype.getTileCoordForTileUrlFunction =
     function(tileCoord, opt_projection) {
-  var projection = goog.isDef(opt_projection) ?
+  var projection = opt_projection !== undefined ?
       opt_projection : this.getProjection();
   var tileGrid = this.getTileGridForProjection(projection);
   goog.asserts.assert(!goog.isNull(tileGrid), 'tile grid needed');
diff --git a/src/ol/source/tileutfgridsource.js b/src/ol/source/tileutfgridsource.js
index f779822e3b..4786fd8d70 100644
--- a/src/ol/source/tileutfgridsource.js
+++ b/src/ol/source/tileutfgridsource.js
@@ -139,7 +139,7 @@ ol.source.TileUTFGrid.prototype.handleTileJSONResponse = function(tileJSON) {
   this.tileUrlFunction_ = ol.TileUrlFunction.createFromTemplates(grids);
 
   if (tileJSON.attribution !== undefined) {
-    var attributionExtent = goog.isDef(extent) ?
+    var attributionExtent = extent !== undefined ?
         extent : epsg4326Projection.getExtent();
     /** @type {Object.<string, Array.<ol.TileRange>>} */
     var tileRanges = {};
@@ -178,8 +178,8 @@ ol.source.TileUTFGrid.prototype.getTile =
     var tileUrl = this.tileUrlFunction_(urlTileCoord, pixelRatio, projection);
     var tile = new ol.source.TileUTFGridTile_(
         tileCoord,
-        goog.isDef(tileUrl) ? ol.TileState.IDLE : ol.TileState.EMPTY,
-        goog.isDef(tileUrl) ? tileUrl : '',
+        tileUrl !== undefined ? ol.TileState.IDLE : ol.TileState.EMPTY,
+        tileUrl !== undefined ? tileUrl : '',
         this.tileGrid.getTileCoordExtent(tileCoord),
         this.preemptive_);
     this.tileCache.set(tileCoordKey, tile);
diff --git a/src/ol/source/tilewmssource.js b/src/ol/source/tilewmssource.js
index 12f8eff1d3..4d1ae44934 100644
--- a/src/ol/source/tilewmssource.js
+++ b/src/ol/source/tilewmssource.js
@@ -337,7 +337,7 @@ ol.source.TileWMS.prototype.resetCoordKeyPrefix_ = function() {
  * @api stable
  */
 ol.source.TileWMS.prototype.setUrl = function(url) {
-  var urls = goog.isDef(url) ? ol.TileUrlFunction.expandUrl(url) : null;
+  var urls = url !== undefined ? ol.TileUrlFunction.expandUrl(url) : null;
   this.setUrls(urls);
 };
 
diff --git a/src/ol/source/vectorsource.js b/src/ol/source/vectorsource.js
index bf698e6ea0..48cd84f0e5 100644
--- a/src/ol/source/vectorsource.js
+++ b/src/ol/source/vectorsource.js
@@ -572,7 +572,7 @@ ol.source.Vector.prototype.getFeatures = function() {
           features, goog.object.getValues(this.nullGeometryFeatures_));
     }
   }
-  goog.asserts.assert(goog.isDef(features),
+  goog.asserts.assert(features !== undefined,
       'Neither featuresRtree_ nor featuresCollection_ are available');
   return features;
 };
@@ -692,7 +692,7 @@ ol.source.Vector.prototype.getExtent = function() {
  */
 ol.source.Vector.prototype.getFeatureById = function(id) {
   var feature = this.idIndex_[id.toString()];
-  return goog.isDef(feature) ? feature : null;
+  return feature !== undefined ? feature : null;
 };
 
 
diff --git a/src/ol/source/wmtssource.js b/src/ol/source/wmtssource.js
index 698a003576..05d646d527 100644
--- a/src/ol/source/wmtssource.js
+++ b/src/ol/source/wmtssource.js
@@ -410,7 +410,7 @@ ol.source.WMTS.optionsFromCapabilities = function(wmtsCap, config) {
       } else {
         value = elt['values'][0];
       }
-      goog.asserts.assert(goog.isDef(value), 'value could be found');
+      goog.asserts.assert(value !== undefined, 'value could be found');
       dimensions[key] = value;
     });
   }
@@ -454,7 +454,7 @@ ol.source.WMTS.optionsFromCapabilities = function(wmtsCap, config) {
   /** @type {!Array.<string>} */
   var urls = [];
   var requestEncoding = config['requestEncoding'];
-  requestEncoding = goog.isDef(requestEncoding) ? requestEncoding : '';
+  requestEncoding = requestEncoding !== undefined ? requestEncoding : '';
 
   goog.asserts.assert(
       goog.array.contains(['REST', 'RESTful', 'KVP', ''], requestEncoding),
diff --git a/src/ol/source/zoomifysource.js b/src/ol/source/zoomifysource.js
index bad8153fbc..235b69fccb 100644
--- a/src/ol/source/zoomifysource.js
+++ b/src/ol/source/zoomifysource.js
@@ -165,7 +165,8 @@ goog.inherits(ol.source.ZoomifyTile_, ol.ImageTile);
  */
 ol.source.ZoomifyTile_.prototype.getImage = function(opt_context) {
   var tileSize = ol.DEFAULT_TILE_SIZE;
-  var key = goog.isDef(opt_context) ? goog.getUid(opt_context).toString() : '';
+  var key = opt_context !== undefined ?
+      goog.getUid(opt_context).toString() : '';
   if (key in this.zoomifyImageByContext_) {
     return this.zoomifyImageByContext_[key];
   } else {
diff --git a/src/ol/structs/lrucache.js b/src/ol/structs/lrucache.js
index 8aac72c41d..656524ad04 100644
--- a/src/ol/structs/lrucache.js
+++ b/src/ol/structs/lrucache.js
@@ -130,7 +130,7 @@ ol.structs.LRUCache.prototype.forEach = function(f, opt_this) {
  */
 ol.structs.LRUCache.prototype.get = function(key) {
   var entry = this.entries_[key];
-  goog.asserts.assert(goog.isDef(entry), 'an entry exists for key %s', key);
+  goog.asserts.assert(entry !== undefined, 'an entry exists for key %s', key);
   if (entry === this.newest_) {
     return entry.value_;
   } else if (entry === this.oldest_) {
diff --git a/src/ol/style/atlasmanager.js b/src/ol/style/atlasmanager.js
index 2c64a703f4..33cc672112 100644
--- a/src/ol/style/atlasmanager.js
+++ b/src/ol/style/atlasmanager.js
@@ -191,7 +191,7 @@ ol.style.AtlasManager.prototype.add =
   // even if no hit-detection entry is requested, we insert a fake entry into
   // the hit-detection atlas, to make sure that the offset is the same for
   // the original image and the hit-detection image.
-  var renderHitCallback = goog.isDef(opt_renderHitCallback) ?
+  var renderHitCallback = opt_renderHitCallback !== undefined ?
       opt_renderHitCallback : goog.functions.NULL;
 
   /** @type {?ol.style.AtlasInfo} */
diff --git a/src/ol/style/iconstyle.js b/src/ol/style/iconstyle.js
index edbb76b90c..df3d85452b 100644
--- a/src/ol/style/iconstyle.js
+++ b/src/ol/style/iconstyle.js
@@ -105,10 +105,10 @@ ol.style.Icon = function(opt_options) {
    */
   var src = options.src;
 
-  goog.asserts.assert(!(goog.isDef(src) && !goog.isNull(image)),
+  goog.asserts.assert(!(src !== undefined && !goog.isNull(image)),
       'image and src can not provided at the same time');
   goog.asserts.assert(
-      src === undefined || (goog.isDef(src) && goog.isNull(imgSize)),
+      src === undefined || (src !== undefined && goog.isNull(imgSize)),
       'imgSize should not be set when src is provided');
   goog.asserts.assert(
       goog.isNull(image) || (!goog.isNull(image) && !goog.isNull(imgSize)),
@@ -117,7 +117,7 @@ ol.style.Icon = function(opt_options) {
   if ((src === undefined || src.length === 0) && !goog.isNull(image)) {
     src = image.src;
   }
-  goog.asserts.assert(goog.isDef(src) && src.length > 0,
+  goog.asserts.assert(src !== undefined && src.length > 0,
       'must provide a defined and non-empty src or image');
 
   /**
@@ -620,7 +620,7 @@ goog.addSingletonGetter(ol.style.IconImageCache);
  * @return {string} Cache key.
  */
 ol.style.IconImageCache.getKey = function(src, crossOrigin) {
-  goog.asserts.assert(goog.isDef(crossOrigin),
+  goog.asserts.assert(crossOrigin !== undefined,
       'argument crossOrigin must be defined');
   return crossOrigin + ':' + src;
 };
diff --git a/src/ol/tilecache.js b/src/ol/tilecache.js
index 2ced7117eb..a06962f998 100644
--- a/src/ol/tilecache.js
+++ b/src/ol/tilecache.js
@@ -21,7 +21,7 @@ ol.TileCache = function(opt_highWaterMark) {
    * @private
    * @type {number}
    */
-  this.highWaterMark_ = goog.isDef(opt_highWaterMark) ?
+  this.highWaterMark_ = opt_highWaterMark !== undefined ?
       opt_highWaterMark : ol.DEFAULT_TILE_CACHE_HIGH_WATER_MARK;
 
 };
diff --git a/src/ol/tilegrid/tilegrid.js b/src/ol/tilegrid/tilegrid.js
index 7efb55ea90..8eb794267b 100644
--- a/src/ol/tilegrid/tilegrid.js
+++ b/src/ol/tilegrid/tilegrid.js
@@ -72,7 +72,7 @@ ol.tilegrid.TileGrid = function(options) {
 
   var extent = options.extent;
 
-  if (goog.isDef(extent) &&
+  if (extent !== undefined &&
       goog.isNull(this.origin_) && goog.isNull(this.origins_)) {
     this.origin_ = ol.extent.getTopLeft(extent);
   }
@@ -109,7 +109,7 @@ ol.tilegrid.TileGrid = function(options) {
    * @private
    * @type {ol.Extent}
    */
-  this.extent_ = goog.isDef(extent) ? extent : null;
+  this.extent_ = extent !== undefined ? extent : null;
 
 
   /**
@@ -127,7 +127,7 @@ ol.tilegrid.TileGrid = function(options) {
       var tileRange = new ol.TileRange(
           Math.min(0, size[0]), Math.max(size[0] - 1, -1),
           Math.min(0, size[1]), Math.max(size[1] - 1, -1));
-      if (this.minZoom <= z && z <= this.maxZoom && goog.isDef(extent)) {
+      if (this.minZoom <= z && z <= this.maxZoom && extent !== undefined) {
         goog.asserts.assert(tileRange.containsTileRange(
             this.getTileRangeForExtentAndZ(extent, z)),
             'extent tile range must not exceed tilegrid width and height');
@@ -527,7 +527,7 @@ ol.tilegrid.getForProjection = function(projection) {
  */
 ol.tilegrid.createForExtent =
     function(extent, opt_maxZoom, opt_tileSize, opt_corner) {
-  var corner = goog.isDef(opt_corner) ?
+  var corner = opt_corner !== undefined ?
       opt_corner : ol.extent.Corner.TOP_LEFT;
 
   var resolutions = ol.tilegrid.resolutionsFromExtent(
@@ -550,7 +550,7 @@ ol.tilegrid.createForExtent =
  */
 ol.tilegrid.createXYZ = function(opt_options) {
   var options = /** @type {olx.tilegrid.TileGridOptions} */ ({});
-  goog.object.extend(options, goog.isDef(opt_options) ?
+  goog.object.extend(options, opt_options !== undefined ?
       opt_options : /** @type {olx.tilegrid.XYZOptions} */ ({}));
   if (options.extent === undefined) {
     options.extent = ol.proj.get('EPSG:3857').getExtent();
@@ -574,13 +574,13 @@ ol.tilegrid.createXYZ = function(opt_options) {
  */
 ol.tilegrid.resolutionsFromExtent =
     function(extent, opt_maxZoom, opt_tileSize) {
-  var maxZoom = goog.isDef(opt_maxZoom) ?
+  var maxZoom = opt_maxZoom !== undefined ?
       opt_maxZoom : ol.DEFAULT_MAX_ZOOM;
 
   var height = ol.extent.getHeight(extent);
   var width = ol.extent.getWidth(extent);
 
-  var tileSize = ol.size.toSize(goog.isDef(opt_tileSize) ?
+  var tileSize = ol.size.toSize(opt_tileSize !== undefined ?
       opt_tileSize : ol.DEFAULT_TILE_SIZE);
   var maxResolution = Math.max(
       width / tileSize[0], height / tileSize[1]);
diff --git a/src/ol/view.js b/src/ol/view.js
index 059d0da86a..b787868f9e 100644
--- a/src/ol/view.js
+++ b/src/ol/view.js
@@ -193,7 +193,7 @@ ol.View.prototype.calculateCenterZoom = function(resolution, anchor) {
   var center;
   var currentCenter = this.getCenter();
   var currentResolution = this.getResolution();
-  if (goog.isDef(currentCenter) && goog.isDef(currentResolution)) {
+  if (currentCenter !== undefined && currentResolution !== undefined) {
     var x = anchor[0] -
         resolution * (anchor[0] - currentCenter[0]) / currentResolution;
     var y = anchor[1] -
@@ -278,10 +278,10 @@ ol.View.prototype.calculateExtent = function(size) {
   goog.asserts.assert(goog.isDefAndNotNull(center),
       'The view center is not defined');
   var resolution = this.getResolution();
-  goog.asserts.assert(goog.isDef(resolution),
+  goog.asserts.assert(resolution !== undefined,
       'The view resolution is not defined');
   var rotation = this.getRotation();
-  goog.asserts.assert(goog.isDef(rotation),
+  goog.asserts.assert(rotation !== undefined,
       'The view rotation is not defined');
 
   return ol.extent.getForViewAndSize(center, resolution, rotation, size);
@@ -404,7 +404,7 @@ ol.View.prototype.getState = function() {
       Math.round(center[0] / resolution) * resolution,
       Math.round(center[1] / resolution) * resolution
     ],
-    projection: goog.isDef(projection) ? projection : null,
+    projection: projection !== undefined ? projection : null,
     resolution: resolution,
     rotation: rotation
   });
@@ -433,7 +433,7 @@ ol.View.prototype.getZoom = function() {
     } while (res > this.minResolution_);
   }
 
-  return goog.isDef(offset) ? this.minZoom_ + offset : offset;
+  return offset !== undefined ? this.minZoom_ + offset : offset;
 };
 
 
@@ -475,7 +475,7 @@ ol.View.prototype.fit = function(geometry, size, opt_options) {
 
   // calculate rotated extent
   var rotation = this.getRotation();
-  goog.asserts.assert(goog.isDef(rotation), 'rotation was not defined');
+  goog.asserts.assert(rotation !== undefined, 'rotation was not defined');
   var cosAngle = Math.cos(-rotation);
   var sinAngle = Math.sin(-rotation);
   var minRotX = +Infinity;
diff --git a/src/ol/webgl/buffer.js b/src/ol/webgl/buffer.js
index 422ca62f6f..023847fc78 100644
--- a/src/ol/webgl/buffer.js
+++ b/src/ol/webgl/buffer.js
@@ -27,13 +27,13 @@ ol.webgl.Buffer = function(opt_arr, opt_usage) {
    * @private
    * @type {Array.<number>}
    */
-  this.arr_ = goog.isDef(opt_arr) ? opt_arr : [];
+  this.arr_ = opt_arr !== undefined ? opt_arr : [];
 
   /**
    * @private
    * @type {number}
    */
-  this.usage_ = goog.isDef(opt_usage) ?
+  this.usage_ = opt_usage !== undefined ?
       opt_usage : ol.webgl.BufferUsage.STATIC_DRAW;
 
 };
diff --git a/src/ol/xml.js b/src/ol/xml.js
index 207405c7aa..622b18569e 100644
--- a/src/ol/xml.js
+++ b/src/ol/xml.js
@@ -391,7 +391,7 @@ ol.xml.makeArrayPusher = function(valueReader, opt_this) {
        * @param {Array.<*>} objectStack Object stack.
        */
       function(node, objectStack) {
-        var value = valueReader.call(goog.isDef(opt_this) ? opt_this : this,
+        var value = valueReader.call(opt_this !== undefined ? opt_this : this,
             node, objectStack);
         if (value !== undefined) {
           var array = objectStack[objectStack.length - 1];
@@ -418,7 +418,7 @@ ol.xml.makeReplacer = function(valueReader, opt_this) {
        * @param {Array.<*>} objectStack Object stack.
        */
       function(node, objectStack) {
-        var value = valueReader.call(goog.isDef(opt_this) ? opt_this : this,
+        var value = valueReader.call(opt_this !== undefined ? opt_this : this,
             node, objectStack);
         if (value !== undefined) {
           objectStack[objectStack.length - 1] = value;
@@ -438,7 +438,7 @@ ol.xml.makeReplacer = function(valueReader, opt_this) {
  */
 ol.xml.makeObjectPropertyPusher =
     function(valueReader, opt_property, opt_this) {
-  goog.asserts.assert(goog.isDef(valueReader),
+  goog.asserts.assert(valueReader !== undefined,
       'undefined valueReader, expected function(this: T, Node, Array.<*>)');
   return (
       /**
@@ -446,12 +446,12 @@ ol.xml.makeObjectPropertyPusher =
        * @param {Array.<*>} objectStack Object stack.
        */
       function(node, objectStack) {
-        var value = valueReader.call(goog.isDef(opt_this) ? opt_this : this,
+        var value = valueReader.call(opt_this !== undefined ? opt_this : this,
             node, objectStack);
         if (value !== undefined) {
           var object = /** @type {Object} */
               (objectStack[objectStack.length - 1]);
-          var property = goog.isDef(opt_property) ?
+          var property = opt_property !== undefined ?
               opt_property : node.localName;
           goog.asserts.assert(goog.isObject(object),
               'entity from stack was not an object');
@@ -472,7 +472,7 @@ ol.xml.makeObjectPropertyPusher =
  */
 ol.xml.makeObjectPropertySetter =
     function(valueReader, opt_property, opt_this) {
-  goog.asserts.assert(goog.isDef(valueReader),
+  goog.asserts.assert(valueReader !== undefined,
       'undefined valueReader, expected function(this: T, Node, Array.<*>)');
   return (
       /**
@@ -480,12 +480,12 @@ ol.xml.makeObjectPropertySetter =
        * @param {Array.<*>} objectStack Object stack.
        */
       function(node, objectStack) {
-        var value = valueReader.call(goog.isDef(opt_this) ? opt_this : this,
+        var value = valueReader.call(opt_this !== undefined ? opt_this : this,
             node, objectStack);
         if (value !== undefined) {
           var object = /** @type {Object} */
               (objectStack[objectStack.length - 1]);
-          var property = goog.isDef(opt_property) ?
+          var property = opt_property !== undefined ?
               opt_property : node.localName;
           goog.asserts.assert(goog.isObject(object),
               'entity from stack was not an object');
@@ -507,7 +507,7 @@ ol.xml.makeObjectPropertySetter =
  */
 ol.xml.makeChildAppender = function(nodeWriter, opt_this) {
   return function(node, value, objectStack) {
-    nodeWriter.call(goog.isDef(opt_this) ? opt_this : this,
+    nodeWriter.call(opt_this !== undefined ? opt_this : this,
         node, value, objectStack);
     var parent = objectStack[objectStack.length - 1];
     goog.asserts.assert(goog.isObject(parent),
@@ -584,7 +584,7 @@ ol.xml.makeSimpleNodeFactory = function(opt_nodeName, opt_namespaceURI) {
         if (opt_namespaceURI === undefined) {
           namespaceURI = node.namespaceURI;
         }
-        goog.asserts.assert(goog.isDef(nodeName), 'nodeName was undefined');
+        goog.asserts.assert(nodeName !== undefined, 'nodeName was undefined');
         return ol.xml.createElementNS(namespaceURI, nodeName);
       }
   );
@@ -637,7 +637,7 @@ ol.xml.makeStructureNS = function(namespaceURIs, structure, opt_structureNS) {
   /**
    * @type {Object.<string, *>}
    */
-  var structureNS = goog.isDef(opt_structureNS) ? opt_structureNS : {};
+  var structureNS = opt_structureNS !== undefined ? opt_structureNS : {};
   var i, ii;
   for (i = 0, ii = namespaceURIs.length; i < ii; ++i) {
     structureNS[namespaceURIs[i]] = structure;
@@ -711,13 +711,13 @@ ol.xml.pushParseAndPop = function(
  */
 ol.xml.serialize = function(
     serializersNS, nodeFactory, values, objectStack, opt_keys, opt_this) {
-  var length = (goog.isDef(opt_keys) ? opt_keys : values).length;
+  var length = (opt_keys !== undefined ? opt_keys : values).length;
   var value, node;
   for (var i = 0; i < length; ++i) {
     value = values[i];
     if (value !== undefined) {
       node = nodeFactory.call(opt_this, value, objectStack,
-          goog.isDef(opt_keys) ? opt_keys[i] : undefined);
+          opt_keys !== undefined ? opt_keys[i] : undefined);
       if (node !== undefined) {
         serializersNS[node.namespaceURI][node.localName]
             .call(opt_this, node, value, objectStack);
diff --git a/test/spec/ol/extent.test.js b/test/spec/ol/extent.test.js
index 1c0235a69c..de372d3f67 100644
--- a/test/spec/ol/extent.test.js
+++ b/test/spec/ol/extent.test.js
@@ -836,7 +836,7 @@ describe('ol.extent', function() {
 
     it('takes arbitrary function', function() {
       var transformFn = function(input, output, opt_dimension) {
-        var dimension = goog.isDef(opt_dimension) ? opt_dimension : 2;
+        var dimension = opt_dimension !== undefined ? opt_dimension : 2;
         if (output === undefined) {
           output = new Array(input.length);
         }
diff --git a/test/spec/ol/interaction/drawinteraction.test.js b/test/spec/ol/interaction/drawinteraction.test.js
index e46d26287d..5deaaf3502 100644
--- a/test/spec/ol/interaction/drawinteraction.test.js
+++ b/test/spec/ol/interaction/drawinteraction.test.js
@@ -48,7 +48,7 @@ describe('ol.interaction.Draw', function() {
     var viewport = map.getViewport();
     // calculated in case body has top < 0 (test runner with small window)
     var position = goog.style.getClientPosition(viewport);
-    var shiftKey = goog.isDef(opt_shiftKey) ? opt_shiftKey : false;
+    var shiftKey = opt_shiftKey !== undefined ? opt_shiftKey : false;
     var event = new ol.MapBrowserPointerEvent(type, map,
         new ol.pointer.PointerEvent(type,
             new goog.events.BrowserEvent({
diff --git a/test/spec/ol/interaction/modifyinteraction.test.js b/test/spec/ol/interaction/modifyinteraction.test.js
index 7fff57b64f..52f5fd1627 100644
--- a/test/spec/ol/interaction/modifyinteraction.test.js
+++ b/test/spec/ol/interaction/modifyinteraction.test.js
@@ -64,7 +64,7 @@ describe('ol.interaction.Modify', function() {
     var viewport = map.getViewport();
     // calculated in case body has top < 0 (test runner with small window)
     var position = goog.style.getClientPosition(viewport);
-    var shiftKey = goog.isDef(opt_shiftKey) ? opt_shiftKey : false;
+    var shiftKey = opt_shiftKey !== undefined ? opt_shiftKey : false;
     var event = new ol.MapBrowserPointerEvent(type, map,
         new ol.pointer.PointerEvent(type,
             new goog.events.BrowserEvent({
diff --git a/test/spec/ol/interaction/selectinteraction.test.js b/test/spec/ol/interaction/selectinteraction.test.js
index af3b98a8da..6e8e331e16 100644
--- a/test/spec/ol/interaction/selectinteraction.test.js
+++ b/test/spec/ol/interaction/selectinteraction.test.js
@@ -79,7 +79,7 @@ describe('ol.interaction.Select', function() {
     var viewport = map.getViewport();
     // calculated in case body has top < 0 (test runner with small window)
     var position = goog.style.getClientPosition(viewport);
-    var shiftKey = goog.isDef(opt_shiftKey) ? opt_shiftKey : false;
+    var shiftKey = opt_shiftKey !== undefined ? opt_shiftKey : false;
     var event = new ol.MapBrowserPointerEvent(type, map,
         new ol.pointer.PointerEvent(type,
             new goog.events.BrowserEvent({
diff --git a/test/spec/ol/interaction/translateinteraction.test.js b/test/spec/ol/interaction/translateinteraction.test.js
index 8526796ae4..fb71855f53 100644
--- a/test/spec/ol/interaction/translateinteraction.test.js
+++ b/test/spec/ol/interaction/translateinteraction.test.js
@@ -54,7 +54,7 @@ describe('ol.interaction.Translate', function() {
     var viewport = map.getViewport();
     // calculated in case body has top < 0 (test runner with small window)
     var position = goog.style.getClientPosition(viewport);
-    var shiftKey = goog.isDef(opt_shiftKey) ? opt_shiftKey : false;
+    var shiftKey = opt_shiftKey !== undefined ? opt_shiftKey : false;
     var event = new ol.MapBrowserPointerEvent(type, map,
         new ol.pointer.PointerEvent(type,
         new goog.events.BrowserEvent({
diff --git a/test/spec/ol/pointer/touchsource.test.js b/test/spec/ol/pointer/touchsource.test.js
index c5d6be0b92..3d4f16adcb 100644
--- a/test/spec/ol/pointer/touchsource.test.js
+++ b/test/spec/ol/pointer/touchsource.test.js
@@ -118,7 +118,7 @@ describe('ol.pointer.TouchSource', function() {
   });
 
   function simulateTouchEvent(type, changedTouches, touches) {
-    touches = goog.isDef(touches) ? touches : changedTouches;
+    touches = touches !== undefined ? touches : changedTouches;
 
     var event = new goog.events.BrowserEvent({
       type: type,
diff --git a/test_rendering/spec/ol/layer/tile.test.js b/test_rendering/spec/ol/layer/tile.test.js
index 0a2bd57d25..c83c974736 100644
--- a/test_rendering/spec/ol/layer/tile.test.js
+++ b/test_rendering/spec/ol/layer/tile.test.js
@@ -11,7 +11,7 @@ describe('ol.rendering.layer.Tile', function() {
       target: target,
       renderer: renderer,
       view: new ol.View({
-        center: goog.isDef(opt_center) ? opt_center : ol.proj.transform(
+        center: opt_center !== undefined ? opt_center : ol.proj.transform(
             [-122.416667, 37.783333], 'EPSG:4326', 'EPSG:3857'),
         zoom: 5
       })