diff --git a/src/ol/style/atlasmanager.js b/src/ol/style/atlasmanager.js
index 01967f8bcd..e83a03b2a6 100644
--- a/src/ol/style/atlasmanager.js
+++ b/src/ol/style/atlasmanager.js
@@ -97,13 +97,12 @@ ol.style.AtlasManager.prototype.getInfo = function(id) {
   /** @type {?ol.style.AtlasInfo} */
   var info = this.getInfo_(this.atlases_, id);
 
-  if (goog.isNull(info)) {
+  if (!info) {
     return null;
   }
   /** @type {?ol.style.AtlasInfo} */
   var hitInfo = this.getInfo_(this.hitAtlases_, id);
-  goog.asserts.assert(!goog.isNull(hitInfo),
-      'hitInfo must not be null');
+  goog.asserts.assert(hitInfo, 'hitInfo must not be null');
 
   return this.mergeInfos_(info, hitInfo);
 };
@@ -121,7 +120,7 @@ ol.style.AtlasManager.prototype.getInfo_ = function(atlases, id) {
   for (i = 0, ii = atlases.length; i < ii; ++i) {
     atlas = atlases[i];
     info = atlas.get(id);
-    if (!goog.isNull(info)) {
+    if (info) {
       return info;
     }
   }
@@ -184,7 +183,7 @@ ol.style.AtlasManager.prototype.add =
   /** @type {?ol.style.AtlasInfo} */
   var info = this.add_(false,
       id, width, height, renderCallback, opt_this);
-  if (goog.isNull(info)) {
+  if (!info) {
     return null;
   }
 
@@ -197,8 +196,7 @@ ol.style.AtlasManager.prototype.add =
   /** @type {?ol.style.AtlasInfo} */
   var hitInfo = this.add_(true,
       id, width, height, renderHitCallback, opt_this);
-  goog.asserts.assert(!goog.isNull(hitInfo),
-      'hitInfo must not be null');
+  goog.asserts.assert(hitInfo, 'hitInfo must not be null');
 
   return this.mergeInfos_(info, hitInfo);
 };
@@ -225,9 +223,9 @@ ol.style.AtlasManager.prototype.add_ =
   for (i = 0, ii = atlases.length; i < ii; ++i) {
     atlas = atlases[i];
     info = atlas.add(id, width, height, renderCallback, opt_this);
-    if (!goog.isNull(info)) {
+    if (info) {
       return info;
-    } else if (goog.isNull(info) && i === ii - 1) {
+    } else if (!info && i === ii - 1) {
       // the entry could not be added to one of the existing atlases,
       // create a new atlas that is twice as big and try to add to this one.
       var size;
diff --git a/src/ol/style/circlestyle.js b/src/ol/style/circlestyle.js
index 08de4b1aa1..007ef3b952 100644
--- a/src/ol/style/circlestyle.js
+++ b/src/ol/style/circlestyle.js
@@ -247,7 +247,7 @@ ol.style.Circle.prototype.render_ = function(atlasManager) {
   var strokeStyle;
   var strokeWidth = 0;
 
-  if (!goog.isNull(this.stroke_)) {
+  if (this.stroke_) {
     strokeStyle = ol.color.asString(this.stroke_.getColor());
     strokeWidth = this.stroke_.getWidth();
     if (strokeWidth === undefined) {
@@ -291,7 +291,7 @@ ol.style.Circle.prototype.render_ = function(atlasManager) {
     // an atlas manager is used, add the symbol to an atlas
     size = Math.round(size);
 
-    var hasCustomHitDetectionImage = goog.isNull(this.fill_);
+    var hasCustomHitDetectionImage = !this.fill_;
     var renderHitDetectionCallback;
     if (hasCustomHitDetectionImage) {
       // render the hit-detection image into a separate atlas image
@@ -303,7 +303,7 @@ ol.style.Circle.prototype.render_ = function(atlasManager) {
     var info = atlasManager.add(
         id, size, size, goog.bind(this.draw_, this, renderOptions),
         renderHitDetectionCallback);
-    goog.asserts.assert(info !== null, 'circle radius is too large');
+    goog.asserts.assert(info, 'circle radius is too large');
 
     this.canvas_ = info.image;
     this.origin_ = [info.offsetX, info.offsetY];
@@ -344,14 +344,14 @@ ol.style.Circle.prototype.draw_ = function(renderOptions, context, x, y) {
       renderOptions.size / 2, renderOptions.size / 2,
       this.radius_, 0, 2 * Math.PI, true);
 
-  if (!goog.isNull(this.fill_)) {
+  if (this.fill_) {
     context.fillStyle = ol.color.asString(this.fill_.getColor());
     context.fill();
   }
-  if (!goog.isNull(this.stroke_)) {
+  if (this.stroke_) {
     context.strokeStyle = renderOptions.strokeStyle;
     context.lineWidth = renderOptions.strokeWidth;
-    if (!goog.isNull(renderOptions.lineDash)) {
+    if (renderOptions.lineDash) {
       context.setLineDash(renderOptions.lineDash);
     }
     context.stroke();
@@ -366,7 +366,7 @@ ol.style.Circle.prototype.draw_ = function(renderOptions, context, x, y) {
  */
 ol.style.Circle.prototype.createHitDetectionCanvas_ = function(renderOptions) {
   this.hitDetectionImageSize_ = [renderOptions.size, renderOptions.size];
-  if (!goog.isNull(this.fill_)) {
+  if (this.fill_) {
     this.hitDetectionCanvas_ = this.canvas_;
     return;
   }
@@ -408,10 +408,10 @@ ol.style.Circle.prototype.drawHitDetectionCanvas_ =
 
   context.fillStyle = ol.color.asString(ol.render.canvas.defaultFillStyle);
   context.fill();
-  if (!goog.isNull(this.stroke_)) {
+  if (this.stroke_) {
     context.strokeStyle = renderOptions.strokeStyle;
     context.lineWidth = renderOptions.strokeWidth;
-    if (!goog.isNull(renderOptions.lineDash)) {
+    if (renderOptions.lineDash) {
       context.setLineDash(renderOptions.lineDash);
     }
     context.stroke();
@@ -424,12 +424,12 @@ ol.style.Circle.prototype.drawHitDetectionCanvas_ =
  * @inheritDoc
  */
 ol.style.Circle.prototype.getChecksum = function() {
-  var strokeChecksum = !goog.isNull(this.stroke_) ?
+  var strokeChecksum = this.stroke_ ?
       this.stroke_.getChecksum() : '-';
-  var fillChecksum = !goog.isNull(this.fill_) ?
+  var fillChecksum = this.fill_ ?
       this.fill_.getChecksum() : '-';
 
-  var recalculate = goog.isNull(this.checksums_) ||
+  var recalculate = !this.checksums_ ||
       (strokeChecksum != this.checksums_[1] ||
       fillChecksum != this.checksums_[2] ||
       this.radius_ != this.checksums_[3]);
diff --git a/src/ol/style/fillstyle.js b/src/ol/style/fillstyle.js
index 5b9d320bc7..e322df400b 100644
--- a/src/ol/style/fillstyle.js
+++ b/src/ol/style/fillstyle.js
@@ -59,7 +59,7 @@ ol.style.Fill.prototype.setColor = function(color) {
  */
 ol.style.Fill.prototype.getChecksum = function() {
   if (this.checksum_ === undefined) {
-    this.checksum_ = 'f' + (!goog.isNull(this.color_) ?
+    this.checksum_ = 'f' + (this.color_ ?
         ol.color.asString(this.color_) : '-');
   }
 
diff --git a/src/ol/style/iconstyle.js b/src/ol/style/iconstyle.js
index df9e840669..8ed89bb392 100644
--- a/src/ol/style/iconstyle.js
+++ b/src/ol/style/iconstyle.js
@@ -104,16 +104,16 @@ ol.style.Icon = function(opt_options) {
    */
   var src = options.src;
 
-  goog.asserts.assert(!(src !== undefined && !goog.isNull(image)),
+  goog.asserts.assert(!(src !== undefined && image),
       'image and src can not provided at the same time');
   goog.asserts.assert(
-      src === undefined || (src !== undefined && goog.isNull(imgSize)),
+      src === undefined || (src !== undefined && !imgSize),
       'imgSize should not be set when src is provided');
   goog.asserts.assert(
-      goog.isNull(image) || (!goog.isNull(image) && !goog.isNull(imgSize)),
+      !image || (image && imgSize),
       'imgSize must be set when image is provided');
 
-  if ((src === undefined || src.length === 0) && !goog.isNull(image)) {
+  if ((src === undefined || src.length === 0) && image) {
     src = image.src;
   }
   goog.asserts.assert(src !== undefined && src.length > 0,
@@ -201,14 +201,14 @@ goog.inherits(ol.style.Icon, ol.style.Image);
  * @api
  */
 ol.style.Icon.prototype.getAnchor = function() {
-  if (!goog.isNull(this.normalizedAnchor_)) {
+  if (this.normalizedAnchor_) {
     return this.normalizedAnchor_;
   }
   var anchor = this.anchor_;
   var size = this.getSize();
   if (this.anchorXUnits_ == ol.style.IconAnchorUnits.FRACTION ||
       this.anchorYUnits_ == ol.style.IconAnchorUnits.FRACTION) {
-    if (goog.isNull(size)) {
+    if (!size) {
       return null;
     }
     anchor = this.anchor_.slice();
@@ -221,7 +221,7 @@ ol.style.Icon.prototype.getAnchor = function() {
   }
 
   if (this.anchorOrigin_ != ol.style.IconOrigin.TOP_LEFT) {
-    if (goog.isNull(size)) {
+    if (!size) {
       return null;
     }
     if (anchor === this.anchor_) {
@@ -290,7 +290,7 @@ ol.style.Icon.prototype.getHitDetectionImage = function(pixelRatio) {
  * @api
  */
 ol.style.Icon.prototype.getOrigin = function() {
-  if (!goog.isNull(this.origin_)) {
+  if (this.origin_) {
     return this.origin_;
   }
   var offset = this.offset_;
@@ -298,7 +298,7 @@ ol.style.Icon.prototype.getOrigin = function() {
   if (this.offsetOrigin_ != ol.style.IconOrigin.TOP_LEFT) {
     var size = this.getSize();
     var iconImageSize = this.iconImage_.getSize();
-    if (goog.isNull(size) || goog.isNull(iconImageSize)) {
+    if (!size || !iconImageSize) {
       return null;
     }
     offset = offset.slice();
@@ -331,7 +331,7 @@ ol.style.Icon.prototype.getSrc = function() {
  * @api
  */
 ol.style.Icon.prototype.getSize = function() {
-  return goog.isNull(this.size_) ? this.iconImage_.getSize() : this.size_;
+  return !this.size_ ? this.iconImage_.getSize() : this.size_;
 };
 
 
@@ -390,9 +390,9 @@ ol.style.IconImage_ = function(image, src, size, crossOrigin, imageState) {
    * @private
    * @type {Image}
    */
-  this.image_ = goog.isNull(image) ? new Image() : image;
+  this.image_ = !image ? new Image() : image;
 
-  if (!goog.isNull(crossOrigin)) {
+  if (crossOrigin) {
     this.image_.crossOrigin = crossOrigin;
   }
 
@@ -441,7 +441,7 @@ goog.inherits(ol.style.IconImage_, goog.events.EventTarget);
 ol.style.IconImage_.get = function(image, src, size, crossOrigin, imageState) {
   var iconImageCache = ol.style.IconImageCache.getInstance();
   var iconImage = iconImageCache.get(src, crossOrigin);
-  if (goog.isNull(iconImage)) {
+  if (!iconImage) {
     iconImage = new ol.style.IconImage_(
         image, src, size, crossOrigin, imageState);
     iconImageCache.set(src, crossOrigin, iconImage);
@@ -516,7 +516,7 @@ ol.style.IconImage_.prototype.getImageState = function() {
  * @return {Image|HTMLCanvasElement} Image element.
  */
 ol.style.IconImage_.prototype.getHitDetectionImage = function(pixelRatio) {
-  if (goog.isNull(this.hitDetectionImage_)) {
+  if (!this.hitDetectionImage_) {
     if (this.tainting_) {
       var width = this.size_[0];
       var height = this.size_[1];
@@ -554,7 +554,7 @@ ol.style.IconImage_.prototype.load = function() {
   if (this.imageState_ == ol.style.ImageState.IDLE) {
     goog.asserts.assert(this.src_ !== undefined,
         'this.src_ must not be undefined');
-    goog.asserts.assert(goog.isNull(this.imageListenerKeys_),
+    goog.asserts.assert(!this.imageListenerKeys_,
         'no listener keys existing');
     this.imageState_ = ol.style.ImageState.LOADING;
     this.imageListenerKeys_ = [
@@ -578,7 +578,7 @@ ol.style.IconImage_.prototype.load = function() {
  * @private
  */
 ol.style.IconImage_.prototype.unlistenImage_ = function() {
-  goog.asserts.assert(!goog.isNull(this.imageListenerKeys_),
+  goog.asserts.assert(this.imageListenerKeys_,
       'we must have listeners registered');
   this.imageListenerKeys_.forEach(goog.events.unlistenByKey);
   this.imageListenerKeys_ = null;
diff --git a/src/ol/style/regularshapestyle.js b/src/ol/style/regularshapestyle.js
index c3da2c16a6..7cb8fc44d5 100644
--- a/src/ol/style/regularshapestyle.js
+++ b/src/ol/style/regularshapestyle.js
@@ -313,7 +313,7 @@ ol.style.RegularShape.prototype.render_ = function(atlasManager) {
   var strokeStyle;
   var strokeWidth = 0;
 
-  if (!goog.isNull(this.stroke_)) {
+  if (this.stroke_) {
     strokeStyle = ol.color.asString(this.stroke_.getColor());
     strokeWidth = this.stroke_.getWidth();
     if (strokeWidth === undefined) {
@@ -371,7 +371,7 @@ ol.style.RegularShape.prototype.render_ = function(atlasManager) {
     // an atlas manager is used, add the symbol to an atlas
     size = Math.round(size);
 
-    var hasCustomHitDetectionImage = goog.isNull(this.fill_);
+    var hasCustomHitDetectionImage = !this.fill_;
     var renderHitDetectionCallback;
     if (hasCustomHitDetectionImage) {
       // render the hit-detection image into a separate atlas image
@@ -383,7 +383,7 @@ ol.style.RegularShape.prototype.render_ = function(atlasManager) {
     var info = atlasManager.add(
         id, size, size, goog.bind(this.draw_, this, renderOptions),
         renderHitDetectionCallback);
-    goog.asserts.assert(!goog.isNull(info), 'shape size is too large');
+    goog.asserts.assert(info, 'shape size is too large');
 
     this.canvas_ = info.image;
     this.origin_ = [info.offsetX, info.offsetY];
@@ -431,14 +431,14 @@ ol.style.RegularShape.prototype.draw_ = function(renderOptions, context, x, y) {
                    renderOptions.size / 2 + radiusC * Math.sin(angle0));
   }
 
-  if (!goog.isNull(this.fill_)) {
+  if (this.fill_) {
     context.fillStyle = ol.color.asString(this.fill_.getColor());
     context.fill();
   }
-  if (!goog.isNull(this.stroke_)) {
+  if (this.stroke_) {
     context.strokeStyle = renderOptions.strokeStyle;
     context.lineWidth = renderOptions.strokeWidth;
-    if (!goog.isNull(renderOptions.lineDash)) {
+    if (renderOptions.lineDash) {
       context.setLineDash(renderOptions.lineDash);
     }
     context.lineCap = renderOptions.lineCap;
@@ -457,7 +457,7 @@ ol.style.RegularShape.prototype.draw_ = function(renderOptions, context, x, y) {
 ol.style.RegularShape.prototype.createHitDetectionCanvas_ =
     function(renderOptions) {
   this.hitDetectionImageSize_ = [renderOptions.size, renderOptions.size];
-  if (!goog.isNull(this.fill_)) {
+  if (this.fill_) {
     this.hitDetectionCanvas_ = this.canvas_;
     return;
   }
@@ -506,10 +506,10 @@ ol.style.RegularShape.prototype.drawHitDetectionCanvas_ =
 
   context.fillStyle = ol.render.canvas.defaultFillStyle;
   context.fill();
-  if (!goog.isNull(this.stroke_)) {
+  if (this.stroke_) {
     context.strokeStyle = renderOptions.strokeStyle;
     context.lineWidth = renderOptions.strokeWidth;
-    if (!goog.isNull(renderOptions.lineDash)) {
+    if (renderOptions.lineDash) {
       context.setLineDash(renderOptions.lineDash);
     }
     context.stroke();
@@ -522,12 +522,12 @@ ol.style.RegularShape.prototype.drawHitDetectionCanvas_ =
  * @inheritDoc
  */
 ol.style.RegularShape.prototype.getChecksum = function() {
-  var strokeChecksum = !goog.isNull(this.stroke_) ?
+  var strokeChecksum = this.stroke_ ?
       this.stroke_.getChecksum() : '-';
-  var fillChecksum = !goog.isNull(this.fill_) ?
+  var fillChecksum = this.fill_ ?
       this.fill_.getChecksum() : '-';
 
-  var recalculate = goog.isNull(this.checksums_) ||
+  var recalculate = !this.checksums_ ||
       (strokeChecksum != this.checksums_[1] ||
       fillChecksum != this.checksums_[2] ||
       this.radius_ != this.checksums_[3] ||
diff --git a/src/ol/style/strokestyle.js b/src/ol/style/strokestyle.js
index 230f32e1fc..52a7e29f86 100644
--- a/src/ol/style/strokestyle.js
+++ b/src/ol/style/strokestyle.js
@@ -205,11 +205,11 @@ ol.style.Stroke.prototype.setWidth = function(width) {
 ol.style.Stroke.prototype.getChecksum = function() {
   if (this.checksum_ === undefined) {
     var raw = 's' +
-        (!goog.isNull(this.color_) ?
+        (this.color_ ?
             ol.color.asString(this.color_) : '-') + ',' +
         (this.lineCap_ !== undefined ?
             this.lineCap_.toString() : '-') + ',' +
-        (!goog.isNull(this.lineDash_) ?
+        (this.lineDash_ ?
             this.lineDash_.toString() : '-') + ',' +
         (this.lineJoin_ !== undefined ?
             this.lineJoin_ : '-') + ',' +
diff --git a/src/ol/style/style.js b/src/ol/style/style.js
index b26910498b..3e4c1d46eb 100644
--- a/src/ol/style/style.js
+++ b/src/ol/style/style.js
@@ -169,7 +169,7 @@ ol.style.Style.prototype.setGeometry = function(geometry) {
       }
       return result;
     };
-  } else if (goog.isNull(geometry)) {
+  } else if (!geometry) {
     this.geometryFunction_ = ol.style.defaultGeometryFunction;
   } else if (geometry !== undefined) {
     goog.asserts.assertInstanceof(geometry, ol.geom.Geometry,
@@ -255,7 +255,7 @@ ol.style.defaultStyleFunction = function(feature, resolution) {
   // browsers that do not support Canvas. (ol.style.Circle does
   // canvas.getContext('2d') at construction time, which will cause an.error
   // in such browsers.)
-  if (goog.isNull(ol.style.defaultStyle_)) {
+  if (!ol.style.defaultStyle_) {
     var fill = new ol.style.Fill({
       color: 'rgba(255,255,255,0.4)'
     });
@@ -366,7 +366,6 @@ ol.style.GeometryFunction;
  * @return {ol.geom.Geometry|undefined} Geometry to render.
  */
 ol.style.defaultGeometryFunction = function(feature) {
-  goog.asserts.assert(!goog.isNull(feature),
-      'feature must not be null');
+  goog.asserts.assert(feature, 'feature must not be null');
   return feature.getGeometry();
 };