diff --git a/src/ol/geom/circle.js b/src/ol/geom/circle.js
index 9a882b32ed..66eeb43c45 100644
--- a/src/ol/geom/circle.js
+++ b/src/ol/geom/circle.js
@@ -23,7 +23,7 @@ goog.require('ol.proj');
  */
 ol.geom.Circle = function(center, opt_radius, opt_layout) {
   goog.base(this);
-  var radius = goog.isDef(opt_radius) ? opt_radius : 0;
+  var radius = opt_radius ? opt_radius : 0;
   this.setCenterAndRadius(center, radius, opt_layout);
 };
 goog.inherits(ol.geom.Circle, ol.geom.SimpleGeometry);
diff --git a/src/ol/geom/flat/closestflatgeom.js b/src/ol/geom/flat/closestflatgeom.js
index 132753aa72..efe7470629 100644
--- a/src/ol/geom/flat/closestflatgeom.js
+++ b/src/ol/geom/flat/closestflatgeom.js
@@ -154,7 +154,7 @@ ol.geom.flat.closest.getClosestPoint = function(flatCoordinates, offset, end,
     }
   }
   goog.asserts.assert(maxDelta > 0, 'maxDelta should be larger than 0');
-  var tmpPoint = goog.isDef(opt_tmpPoint) ? opt_tmpPoint : [NaN, NaN];
+  var tmpPoint = opt_tmpPoint ? opt_tmpPoint : [NaN, NaN];
   var index = offset + stride;
   while (index < end) {
     ol.geom.flat.closest.point(
@@ -217,7 +217,7 @@ ol.geom.flat.closest.getClosestPoint = function(flatCoordinates, offset, end,
 ol.geom.flat.closest.getsClosestPoint = function(flatCoordinates, offset, ends,
     stride, maxDelta, isRing, x, y, closestPoint, minSquaredDistance,
     opt_tmpPoint) {
-  var tmpPoint = goog.isDef(opt_tmpPoint) ? opt_tmpPoint : [NaN, NaN];
+  var tmpPoint = opt_tmpPoint ? opt_tmpPoint : [NaN, NaN];
   var i, ii;
   for (i = 0, ii = ends.length; i < ii; ++i) {
     var end = ends[i];
@@ -247,7 +247,7 @@ ol.geom.flat.closest.getsClosestPoint = function(flatCoordinates, offset, ends,
 ol.geom.flat.closest.getssClosestPoint = function(flatCoordinates, offset,
     endss, stride, maxDelta, isRing, x, y, closestPoint, minSquaredDistance,
     opt_tmpPoint) {
-  var tmpPoint = goog.isDef(opt_tmpPoint) ? opt_tmpPoint : [NaN, NaN];
+  var tmpPoint = opt_tmpPoint ? opt_tmpPoint : [NaN, NaN];
   var i, ii;
   for (i = 0, ii = endss.length; i < ii; ++i) {
     var ends = endss[i];
diff --git a/src/ol/geom/flat/deflateflatgeom.js b/src/ol/geom/flat/deflateflatgeom.js
index 069467e3fe..08c7fe7b02 100644
--- a/src/ol/geom/flat/deflateflatgeom.js
+++ b/src/ol/geom/flat/deflateflatgeom.js
@@ -55,7 +55,7 @@ ol.geom.flat.deflate.coordinates =
  */
 ol.geom.flat.deflate.coordinatess =
     function(flatCoordinates, offset, coordinatess, stride, opt_ends) {
-  var ends = goog.isDef(opt_ends) ? opt_ends : [];
+  var ends = opt_ends ? opt_ends : [];
   var i = 0;
   var j, jj;
   for (j = 0, jj = coordinatess.length; j < jj; ++j) {
@@ -79,7 +79,7 @@ ol.geom.flat.deflate.coordinatess =
  */
 ol.geom.flat.deflate.coordinatesss =
     function(flatCoordinates, offset, coordinatesss, stride, opt_endss) {
-  var endss = goog.isDef(opt_endss) ? opt_endss : [];
+  var endss = opt_endss ? opt_endss : [];
   var i = 0;
   var j, jj;
   for (j = 0, jj = coordinatesss.length; j < jj; ++j) {
diff --git a/src/ol/geom/flat/interiorpointflatgeom.js b/src/ol/geom/flat/interiorpointflatgeom.js
index 883f9cffa0..59e69242b2 100644
--- a/src/ol/geom/flat/interiorpointflatgeom.js
+++ b/src/ol/geom/flat/interiorpointflatgeom.js
@@ -60,7 +60,7 @@ ol.geom.flat.interiorpoint.linearRings = function(flatCoordinates, offset,
     // ring.  Use the center of the the linear ring's extent.
     pointX = flatCenters[flatCentersOffset];
   }
-  if (goog.isDef(opt_dest)) {
+  if (opt_dest) {
     opt_dest.push(pointX, y);
     return opt_dest;
   } else {
diff --git a/src/ol/geom/flat/orientflatgeom.js b/src/ol/geom/flat/orientflatgeom.js
index 688b6a3f97..5b80341ce8 100644
--- a/src/ol/geom/flat/orientflatgeom.js
+++ b/src/ol/geom/flat/orientflatgeom.js
@@ -1,5 +1,6 @@
 goog.provide('ol.geom.flat.orient');
 
+goog.require('ol');
 goog.require('ol.geom.flat.reverse');
 
 
@@ -43,7 +44,7 @@ ol.geom.flat.orient.linearRingIsClockwise =
  */
 ol.geom.flat.orient.linearRingsAreOriented =
     function(flatCoordinates, offset, ends, stride, opt_right) {
-  var right = goog.isDef(opt_right) ? opt_right : false;
+  var right = ol.isDef(opt_right) ? opt_right : false;
   var i, ii;
   for (i = 0, ii = ends.length; i < ii; ++i) {
     var end = ends[i];
@@ -105,7 +106,7 @@ ol.geom.flat.orient.linearRingssAreOriented =
  */
 ol.geom.flat.orient.orientLinearRings =
     function(flatCoordinates, offset, ends, stride, opt_right) {
-  var right = goog.isDef(opt_right) ? opt_right : false;
+  var right = ol.isDef(opt_right) ? opt_right : false;
   var i, ii;
   for (i = 0, ii = ends.length; i < ii; ++i) {
     var end = ends[i];
diff --git a/src/ol/geom/flat/transformflatgeom.js b/src/ol/geom/flat/transformflatgeom.js
index 7bb08e8a83..81ecf4a53c 100644
--- a/src/ol/geom/flat/transformflatgeom.js
+++ b/src/ol/geom/flat/transformflatgeom.js
@@ -20,7 +20,7 @@ ol.geom.flat.transform.transform2D =
   var m11 = goog.vec.Mat4.getElement(transform, 1, 1);
   var m03 = goog.vec.Mat4.getElement(transform, 0, 3);
   var m13 = goog.vec.Mat4.getElement(transform, 1, 3);
-  var dest = goog.isDef(opt_dest) ? opt_dest : [];
+  var dest = opt_dest ? opt_dest : [];
   var i = 0;
   var j;
   for (j = offset; j < end; j += stride) {
@@ -29,7 +29,7 @@ ol.geom.flat.transform.transform2D =
     dest[i++] = m00 * x + m01 * y + m03;
     dest[i++] = m10 * x + m11 * y + m13;
   }
-  if (goog.isDef(opt_dest) && dest.length != i) {
+  if (opt_dest && dest.length != i) {
     dest.length = i;
   }
   return dest;
@@ -48,7 +48,7 @@ ol.geom.flat.transform.transform2D =
  */
 ol.geom.flat.transform.translate =
     function(flatCoordinates, offset, end, stride, deltaX, deltaY, opt_dest) {
-  var dest = goog.isDef(opt_dest) ? opt_dest : [];
+  var dest = opt_dest ? opt_dest : [];
   var i = 0;
   var j, k;
   for (j = offset; j < end; j += stride) {
@@ -58,7 +58,7 @@ ol.geom.flat.transform.translate =
       dest[i++] = flatCoordinates[k];
     }
   }
-  if (goog.isDef(opt_dest) && dest.length != i) {
+  if (opt_dest && dest.length != i) {
     dest.length = i;
   }
   return dest;
diff --git a/src/ol/geom/geometry.js b/src/ol/geom/geometry.js
index c75da4f1eb..70fac46257 100644
--- a/src/ol/geom/geometry.js
+++ b/src/ol/geom/geometry.js
@@ -122,8 +122,7 @@ ol.geom.Geometry.prototype.closestPointXY = goog.abstractMethod;
  * @api stable
  */
 ol.geom.Geometry.prototype.getClosestPoint = function(point, opt_closestPoint) {
-  var closestPoint = goog.isDef(opt_closestPoint) ?
-      opt_closestPoint : [NaN, NaN];
+  var closestPoint = opt_closestPoint ? opt_closestPoint : [NaN, NaN];
   this.closestPointXY(point[0], point[1], closestPoint, Infinity);
   return closestPoint;
 };
diff --git a/src/ol/geom/geometrycollection.js b/src/ol/geom/geometrycollection.js
index 7ac3963fde..548f389736 100644
--- a/src/ol/geom/geometrycollection.js
+++ b/src/ol/geom/geometrycollection.js
@@ -26,7 +26,7 @@ ol.geom.GeometryCollection = function(opt_geometries) {
    * @private
    * @type {Array.<ol.geom.Geometry>}
    */
-  this.geometries_ = goog.isDef(opt_geometries) ? opt_geometries : null;
+  this.geometries_ = opt_geometries ? opt_geometries : null;
 
   this.listenGeometriesChange_();
 };
diff --git a/src/ol/geom/multilinestring.js b/src/ol/geom/multilinestring.js
index fb3d94af48..30b3b5afdd 100644
--- a/src/ol/geom/multilinestring.js
+++ b/src/ol/geom/multilinestring.js
@@ -2,6 +2,7 @@ goog.provide('ol.geom.MultiLineString');
 
 goog.require('goog.array');
 goog.require('goog.asserts');
+goog.require('ol');
 goog.require('ol.extent');
 goog.require('ol.geom.GeometryLayout');
 goog.require('ol.geom.GeometryType');
@@ -135,8 +136,10 @@ ol.geom.MultiLineString.prototype.getCoordinateAtM =
       this.flatCoordinates.length === 0) {
     return null;
   }
-  var extrapolate = goog.isDef(opt_extrapolate) ? opt_extrapolate : false;
-  var interpolate = goog.isDef(opt_interpolate) ? opt_interpolate : false;
+  var extrapolate = ol.isDef(opt_extrapolate) ?
+      /** @type {boolean} */ (opt_extrapolate) : false;
+  var interpolate = ol.isDef(opt_interpolate) ?
+      /** @type {boolean} */ (opt_interpolate) : false;
   return ol.geom.flat.lineStringsCoordinateAtM(this.flatCoordinates, 0,
       this.ends_, this.stride, m, extrapolate, interpolate);
 };
diff --git a/src/ol/geom/multipolygon.js b/src/ol/geom/multipolygon.js
index d74c7b781d..41b56f8d16 100644
--- a/src/ol/geom/multipolygon.js
+++ b/src/ol/geom/multipolygon.js
@@ -3,6 +3,7 @@ goog.provide('ol.geom.MultiPolygon');
 goog.require('goog.array');
 goog.require('goog.asserts');
 goog.require('goog.object');
+goog.require('ol');
 goog.require('ol.extent');
 goog.require('ol.geom.GeometryLayout');
 goog.require('ol.geom.GeometryType');
@@ -182,7 +183,7 @@ ol.geom.MultiPolygon.prototype.getArea = function() {
  */
 ol.geom.MultiPolygon.prototype.getCoordinates = function(opt_right) {
   var flatCoordinates;
-  if (goog.isDef(opt_right)) {
+  if (ol.isDef(opt_right)) {
     flatCoordinates = this.getOrientedFlatCoordinates().slice();
     ol.geom.flat.orient.orientLinearRingss(
         flatCoordinates, 0, this.endss_, this.stride, opt_right);
diff --git a/src/ol/geom/polygon.js b/src/ol/geom/polygon.js
index b16263c2ac..a93ded2d54 100644
--- a/src/ol/geom/polygon.js
+++ b/src/ol/geom/polygon.js
@@ -3,6 +3,7 @@ goog.provide('ol.geom.Polygon');
 goog.require('goog.array');
 goog.require('goog.asserts');
 goog.require('goog.math');
+goog.require('ol');
 goog.require('ol.extent');
 goog.require('ol.geom.GeometryLayout');
 goog.require('ol.geom.GeometryType');
@@ -169,7 +170,7 @@ ol.geom.Polygon.prototype.getArea = function() {
  */
 ol.geom.Polygon.prototype.getCoordinates = function(opt_right) {
   var flatCoordinates;
-  if (goog.isDef(opt_right)) {
+  if (ol.isDef(opt_right)) {
     flatCoordinates = this.getOrientedFlatCoordinates().slice();
     ol.geom.flat.orient.orientLinearRings(
         flatCoordinates, 0, this.ends_, this.stride, opt_right);
@@ -388,7 +389,7 @@ ol.geom.Polygon.prototype.setFlatCoordinates =
  * @api stable
  */
 ol.geom.Polygon.circular = function(sphere, center, radius, opt_n) {
-  var n = goog.isDef(opt_n) ? opt_n : 32;
+  var n = opt_n ? opt_n : 32;
   /** @type {Array.<number>} */
   var flatCoordinates = [];
   var i;
@@ -434,7 +435,7 @@ ol.geom.Polygon.fromExtent = function(extent) {
  * @api
  */
 ol.geom.Polygon.fromCircle = function(circle, opt_sides, opt_angle) {
-  var sides = goog.isDef(opt_sides) ? opt_sides : 32;
+  var sides = opt_sides ? opt_sides : 32;
   var stride = circle.getStride();
   var layout = circle.getLayout();
   var polygon = new ol.geom.Polygon(null, layout);
@@ -462,7 +463,7 @@ ol.geom.Polygon.makeRegular = function(polygon, center, radius, opt_angle) {
   var ends = polygon.getEnds();
   goog.asserts.assert(ends.length === 1, 'only 1 ring is supported');
   var sides = flatCoordinates.length / stride - 1;
-  var startAngle = goog.isDef(opt_angle) ? opt_angle : 0;
+  var startAngle = opt_angle ? opt_angle : 0;
   var angle, coord, offset;
   for (var i = 0; i <= sides; ++i) {
     offset = i * stride;
diff --git a/src/ol/geom/simplegeometry.js b/src/ol/geom/simplegeometry.js
index e99e5479b9..4da4b706ad 100644
--- a/src/ol/geom/simplegeometry.js
+++ b/src/ol/geom/simplegeometry.js
@@ -232,7 +232,7 @@ ol.geom.SimpleGeometry.prototype.setLayout =
     function(layout, coordinates, nesting) {
   /** @type {number} */
   var stride;
-  if (goog.isDef(layout)) {
+  if (layout) {
     stride = ol.geom.SimpleGeometry.getStrideForLayout(layout);
   } else {
     var i;