diff --git a/src/ol/featureloader.js b/src/ol/featureloader.js
index bb43fce904..0450108f19 100644
--- a/src/ol/featureloader.js
+++ b/src/ol/featureloader.js
@@ -84,7 +84,7 @@ ol.featureloader.loadFeaturesXhr = function(url, format, success) {
                   if (!goog.userAgent.IE) {
                     source = xhrIo.getResponseXml();
                   }
-                  if (!goog.isDefAndNotNull(source)) {
+                  if (!source) {
                     source = ol.xml.parse(xhrIo.getResponseText());
                   }
                 } else {
diff --git a/src/ol/proj/proj.js b/src/ol/proj/proj.js
index dbfa0e1c26..4ca31665df 100644
--- a/src/ol/proj/proj.js
+++ b/src/ol/proj/proj.js
@@ -484,7 +484,7 @@ ol.proj.clearAllProjections = function() {
  * @return {ol.proj.Projection} Projection.
  */
 ol.proj.createProjection = function(projection, defaultCode) {
-  if (!goog.isDefAndNotNull(projection)) {
+  if (!projection) {
     return ol.proj.get(defaultCode);
   } else if (goog.isString(projection)) {
     return ol.proj.get(projection);
diff --git a/src/ol/render/vector.js b/src/ol/render/vector.js
index 16c5c878e1..4623c46a6d 100644
--- a/src/ol/render/vector.js
+++ b/src/ol/render/vector.js
@@ -121,7 +121,7 @@ ol.renderer.vector.renderFeature = function(
 ol.renderer.vector.renderFeature_ = function(
     replayGroup, feature, style, squaredTolerance) {
   var geometry = style.getGeometryFunction()(feature);
-  if (!goog.isDefAndNotNull(geometry)) {
+  if (!geometry) {
     return;
   }
   var simplifiedGeometry = geometry.getSimplifiedGeometry(squaredTolerance);
diff --git a/src/ol/renderer/canvas/canvasvectorlayerrenderer.js b/src/ol/renderer/canvas/canvasvectorlayerrenderer.js
index 48f0ae7b96..14f27ef406 100644
--- a/src/ol/renderer/canvas/canvasvectorlayerrenderer.js
+++ b/src/ol/renderer/canvas/canvasvectorlayerrenderer.js
@@ -328,7 +328,7 @@ ol.renderer.canvas.VectorLayer.prototype.prepareFrame =
  */
 ol.renderer.canvas.VectorLayer.prototype.renderFeature =
     function(feature, resolution, pixelRatio, styles, replayGroup) {
-  if (!goog.isDefAndNotNull(styles)) {
+  if (!styles) {
     return false;
   }
   var i, ii, loading = false;
diff --git a/src/ol/renderer/dom/domvectorlayerrenderer.js b/src/ol/renderer/dom/domvectorlayerrenderer.js
index 7f8de3a354..28844f426e 100644
--- a/src/ol/renderer/dom/domvectorlayerrenderer.js
+++ b/src/ol/renderer/dom/domvectorlayerrenderer.js
@@ -336,7 +336,7 @@ ol.renderer.dom.VectorLayer.prototype.prepareFrame =
  */
 ol.renderer.dom.VectorLayer.prototype.renderFeature =
     function(feature, resolution, pixelRatio, styles, replayGroup) {
-  if (!goog.isDefAndNotNull(styles)) {
+  if (!styles) {
     return false;
   }
   var i, ii, loading = false;
diff --git a/src/ol/renderer/webgl/webglvectorlayerrenderer.js b/src/ol/renderer/webgl/webglvectorlayerrenderer.js
index b28f131b40..ae53499fcd 100644
--- a/src/ol/renderer/webgl/webglvectorlayerrenderer.js
+++ b/src/ol/renderer/webgl/webglvectorlayerrenderer.js
@@ -304,7 +304,7 @@ ol.renderer.webgl.VectorLayer.prototype.prepareFrame =
  */
 ol.renderer.webgl.VectorLayer.prototype.renderFeature =
     function(feature, resolution, pixelRatio, styles, replayGroup) {
-  if (!goog.isDefAndNotNull(styles)) {
+  if (!styles) {
     return false;
   }
   var i, ii, loading = false;
diff --git a/src/ol/source/imagevectorsource.js b/src/ol/source/imagevectorsource.js
index 86594e4188..4e8dc606f0 100644
--- a/src/ol/source/imagevectorsource.js
+++ b/src/ol/source/imagevectorsource.js
@@ -265,7 +265,7 @@ ol.source.ImageVector.prototype.renderFeature_ =
   } else if (this.styleFunction_) {
     styles = this.styleFunction_(feature, resolution);
   }
-  if (!goog.isDefAndNotNull(styles)) {
+  if (!styles) {
     return false;
   }
   var i, ii, loading = false;
diff --git a/src/ol/source/tileutfgridsource.js b/src/ol/source/tileutfgridsource.js
index 28e96efabb..76e59302fb 100644
--- a/src/ol/source/tileutfgridsource.js
+++ b/src/ol/source/tileutfgridsource.js
@@ -131,7 +131,7 @@ ol.source.TileUTFGrid.prototype.handleTileJSONResponse = function(tileJSON) {
   this.template_ = tileJSON.template;
 
   var grids = tileJSON.grids;
-  if (!goog.isDefAndNotNull(grids)) {
+  if (!grids) {
     this.setState(ol.source.State.ERROR);
     return;
   }
diff --git a/src/ol/source/vectorsource.js b/src/ol/source/vectorsource.js
index f3d20da76e..638f5bfb0f 100644
--- a/src/ol/source/vectorsource.js
+++ b/src/ol/source/vectorsource.js
@@ -705,7 +705,7 @@ ol.source.Vector.prototype.handleFeatureChange_ = function(event) {
   var feature = /** @type {ol.Feature} */ (event.target);
   var featureKey = goog.getUid(feature).toString();
   var geometry = feature.getGeometry();
-  if (!goog.isDefAndNotNull(geometry)) {
+  if (!geometry) {
     if (!(featureKey in this.nullGeometryFeatures_)) {
       if (!goog.isNull(this.featuresRtree_)) {
         this.featuresRtree_.remove(feature);