diff --git a/src/ol/format/esrijsonformat.js b/src/ol/format/esrijsonformat.js
index 2863816334..4465a30a82 100644
--- a/src/ol/format/esrijsonformat.js
+++ b/src/ol/format/esrijsonformat.js
@@ -54,7 +54,7 @@ goog.inherits(ol.format.EsriJSON, ol.format.JSONFeature);
  * @return {ol.geom.Geometry} Geometry.
  */
 ol.format.EsriJSON.readGeometry_ = function(object, opt_options) {
-  if (goog.isNull(object)) {
+  if (!object) {
     return null;
   }
   var type;
diff --git a/src/ol/format/featureformat.js b/src/ol/format/featureformat.js
index 6f6f58aa1a..59d0c77943 100644
--- a/src/ol/format/featureformat.js
+++ b/src/ol/format/featureformat.js
@@ -165,7 +165,7 @@ ol.format.Feature.transformWithOptions = function(
       ol.proj.get(opt_options.featureProjection) : null;
   var dataProjection = opt_options ?
       ol.proj.get(opt_options.dataProjection) : null;
-  if (!goog.isNull(featureProjection) && !goog.isNull(dataProjection) &&
+  if (featureProjection && dataProjection &&
       !ol.proj.equivalent(featureProjection, dataProjection)) {
     if (geometry instanceof ol.geom.Geometry) {
       return (write ? geometry.clone() : geometry).transform(
diff --git a/src/ol/format/geojsonformat.js b/src/ol/format/geojsonformat.js
index cb6db7aa0c..d87be696a4 100644
--- a/src/ol/format/geojsonformat.js
+++ b/src/ol/format/geojsonformat.js
@@ -68,7 +68,7 @@ ol.format.GeoJSON.EXTENSIONS_ = ['.geojson'];
  * @return {ol.geom.Geometry} Geometry.
  */
 ol.format.GeoJSON.readGeometry_ = function(object, opt_options) {
-  if (goog.isNull(object)) {
+  if (!object) {
     return null;
   }
   var geometryReader = ol.format.GeoJSON.GEOMETRY_READERS_[object.type];
diff --git a/src/ol/format/gml/gml2format.js b/src/ol/format/gml/gml2format.js
index 88ff8a5671..30179f6b6b 100644
--- a/src/ol/format/gml/gml2format.js
+++ b/src/ol/format/gml/gml2format.js
@@ -62,20 +62,20 @@ ol.format.GML2.prototype.readFlatCoordinates_ = function(node, objectStack) {
   var containerSrs = context['srsName'];
   var containerDimension = node.parentNode.getAttribute('srsDimension');
   var axisOrientation = 'enu';
-  if (!goog.isNull(containerSrs)) {
+  if (containerSrs) {
     var proj = ol.proj.get(containerSrs);
     axisOrientation = proj.getAxisOrientation();
   }
   var coords = s.split(/[\s,]+/);
   // The "dimension" attribute is from the GML 3.0.1 spec.
   var dim = 2;
-  if (!goog.isNull(node.getAttribute('srsDimension'))) {
+  if (node.getAttribute('srsDimension')) {
     dim = ol.format.XSD.readNonNegativeIntegerString(
         node.getAttribute('srsDimension'));
-  } else if (!goog.isNull(node.getAttribute('dimension'))) {
+  } else if (node.getAttribute('dimension')) {
     dim = ol.format.XSD.readNonNegativeIntegerString(
         node.getAttribute('dimension'));
-  } else if (!goog.isNull(containerDimension)) {
+  } else if (containerDimension) {
     dim = ol.format.XSD.readNonNegativeIntegerString(containerDimension);
   }
   var x, y, z;
diff --git a/src/ol/format/gml/gml3format.js b/src/ol/format/gml/gml3format.js
index b908744af3..94f04feb2d 100644
--- a/src/ol/format/gml/gml3format.js
+++ b/src/ol/format/gml/gml3format.js
@@ -301,7 +301,7 @@ ol.format.GML3.prototype.readSurface_ = function(node, objectStack) {
   var flatLinearRings = ol.xml.pushParseAndPop(
       /** @type {Array.<Array.<number>>} */ ([null]),
       this.SURFACE_PARSERS_, node, objectStack, this);
-  if (flatLinearRings && !goog.isNull(flatLinearRings[0])) {
+  if (flatLinearRings && flatLinearRings[0]) {
     var polygon = new ol.geom.Polygon(null);
     var flatCoordinates = flatLinearRings[0];
     var ends = [flatCoordinates.length];
@@ -385,7 +385,7 @@ ol.format.GML3.prototype.readFlatPos_ = function(node, objectStack) {
   goog.asserts.assert(goog.isObject(context), 'context should be an Object');
   var containerSrs = context['srsName'];
   var axisOrientation = 'enu';
-  if (!goog.isNull(containerSrs)) {
+  if (containerSrs) {
     var proj = ol.proj.get(containerSrs);
     axisOrientation = proj.getAxisOrientation();
   }
@@ -422,20 +422,20 @@ ol.format.GML3.prototype.readFlatPosList_ = function(node, objectStack) {
   var containerSrs = context['srsName'];
   var containerDimension = node.parentNode.getAttribute('srsDimension');
   var axisOrientation = 'enu';
-  if (!goog.isNull(containerSrs)) {
+  if (containerSrs) {
     var proj = ol.proj.get(containerSrs);
     axisOrientation = proj.getAxisOrientation();
   }
   var coords = s.split(/\s+/);
   // The "dimension" attribute is from the GML 3.0.1 spec.
   var dim = 2;
-  if (!goog.isNull(node.getAttribute('srsDimension'))) {
+  if (node.getAttribute('srsDimension')) {
     dim = ol.format.XSD.readNonNegativeIntegerString(
         node.getAttribute('srsDimension'));
-  } else if (!goog.isNull(node.getAttribute('dimension'))) {
+  } else if (node.getAttribute('dimension')) {
     dim = ol.format.XSD.readNonNegativeIntegerString(
         node.getAttribute('dimension'));
-  } else if (!goog.isNull(containerDimension)) {
+  } else if (containerDimension) {
     dim = ol.format.XSD.readNonNegativeIntegerString(containerDimension);
   }
   var x, y, z;
@@ -1067,7 +1067,7 @@ ol.format.GML3.prototype.writeFeatureElement =
   var keys = [], values = [];
   for (var key in properties) {
     var value = properties[key];
-    if (!goog.isNull(value)) {
+    if (value !== null) {
       keys.push(key);
       values.push(value);
       if (key == geometryName) {
diff --git a/src/ol/format/gml/gmlbaseformat.js b/src/ol/format/gml/gmlbaseformat.js
index 5f7cc9826a..e82c292160 100644
--- a/src/ol/format/gml/gmlbaseformat.js
+++ b/src/ol/format/gml/gmlbaseformat.js
@@ -199,8 +199,7 @@ ol.format.GMLBase.prototype.readFeatureElement = function(node, objectStack) {
   var fid = node.getAttribute('fid') ||
       ol.xml.getAttributeNS(node, ol.format.GMLBase.GMLNS, 'id');
   var values = {}, geometryName;
-  for (n = node.firstElementChild; !goog.isNull(n);
-      n = n.nextElementSibling) {
+  for (n = node.firstElementChild; n; n = n.nextElementSibling) {
     var localName = ol.xml.getLocalName(n);
     // Assume attribute elements have one child node and that the child
     // is a text or CDATA node (to be treated as text).
@@ -449,8 +448,7 @@ ol.format.GMLBase.prototype.readPolygon = function(node, objectStack) {
   var flatLinearRings = ol.xml.pushParseAndPop(
       /** @type {Array.<Array.<number>>} */ ([null]),
       this.FLAT_LINEAR_RINGS_PARSERS_, node, objectStack, this);
-  if (flatLinearRings &&
-      !goog.isNull(flatLinearRings[0])) {
+  if (flatLinearRings && flatLinearRings[0]) {
     var polygon = new ol.geom.Polygon(null);
     var flatCoordinates = flatLinearRings[0];
     var ends = [flatCoordinates.length];
diff --git a/src/ol/format/gpxformat.js b/src/ol/format/gpxformat.js
index 25a7363357..bb83768e7d 100644
--- a/src/ol/format/gpxformat.js
+++ b/src/ol/format/gpxformat.js
@@ -97,7 +97,7 @@ ol.format.GPX.parseLink_ = function(node, objectStack) {
   goog.asserts.assert(node.localName == 'link', 'localName should be link');
   var values = /** @type {Object} */ (objectStack[objectStack.length - 1]);
   var href = node.getAttribute('href');
-  if (!goog.isNull(href)) {
+  if (href !== null) {
     values['link'] = href;
   }
   ol.xml.parseNode(ol.format.GPX.LINK_PARSERS_, node, objectStack);
@@ -417,7 +417,7 @@ ol.format.GPX.WPT_PARSERS_ = ol.xml.makeStructureNS(
  * @private
  */
 ol.format.GPX.prototype.handleReadExtensions_ = function(features) {
-  if (goog.isNull(features)) {
+  if (!features) {
     features = [];
   }
   for (var i = 0, ii = features.length; i < ii; ++i) {
diff --git a/src/ol/format/igcformat.js b/src/ol/format/igcformat.js
index 8a2f7a0bb4..a03b48375b 100644
--- a/src/ol/format/igcformat.js
+++ b/src/ol/format/igcformat.js
@@ -202,7 +202,7 @@ ol.format.IGC.prototype.readFeatures;
  */
 ol.format.IGC.prototype.readFeaturesFromText = function(text, opt_options) {
   var feature = this.readFeatureFromText(text, opt_options);
-  if (!goog.isNull(feature)) {
+  if (feature) {
     return [feature];
   } else {
     return [];
diff --git a/src/ol/format/kmlformat.js b/src/ol/format/kmlformat.js
index 9f7cf28940..dbb1d42540 100644
--- a/src/ol/format/kmlformat.js
+++ b/src/ol/format/kmlformat.js
@@ -979,7 +979,7 @@ ol.format.KML.readPolygon_ = function(node, objectStack) {
   var flatLinearRings = ol.xml.pushParseAndPop(
       /** @type {Array.<Array.<number>>} */ ([null]),
       ol.format.KML.FLAT_LINEAR_RINGS_PARSERS_, node, objectStack);
-  if (flatLinearRings && !goog.isNull(flatLinearRings[0])) {
+  if (flatLinearRings && flatLinearRings[0]) {
     var polygon = new ol.geom.Polygon(null);
     var flatCoordinates = flatLinearRings[0];
     var ends = [flatCoordinates.length];
@@ -1085,7 +1085,7 @@ ol.format.KML.DataParser_ = function(node, objectStack) {
       'node.nodeType should be ELEMENT');
   goog.asserts.assert(node.localName == 'Data', 'localName should be Data');
   var name = node.getAttribute('name');
-  if (!goog.isNull(name)) {
+  if (name !== null) {
     var data = ol.xml.pushParseAndPop(
         undefined, ol.format.KML.DATA_PARSERS_, node, objectStack);
     if (data) {
@@ -1196,7 +1196,7 @@ ol.format.KML.SimpleDataParser_ = function(node, objectStack) {
   goog.asserts.assert(node.localName == 'SimpleData',
       'localName should be SimpleData');
   var name = node.getAttribute('name');
-  if (!goog.isNull(name)) {
+  if (name !== null) {
     var data = ol.format.XSD.readString(node);
     var featureObject =
         /** @type {Object} */ (objectStack[objectStack.length - 1]);
@@ -1679,7 +1679,7 @@ ol.format.KML.prototype.readPlacemark_ = function(node, objectStack) {
   }
   var feature = new ol.Feature();
   var id = node.getAttribute('id');
-  if (!goog.isNull(id)) {
+  if (id !== null) {
     feature.setId(id);
   }
   var options = /** @type {olx.format.ReadOptions} */ (objectStack[0]);
@@ -1718,7 +1718,7 @@ ol.format.KML.prototype.readSharedStyle_ = function(node, objectStack) {
       'node.nodeType should be ELEMENT');
   goog.asserts.assert(node.localName == 'Style', 'localName should be Style');
   var id = node.getAttribute('id');
-  if (!goog.isNull(id)) {
+  if (id !== null) {
     var style = ol.format.KML.readStyle_(node, objectStack);
     if (style) {
       var styleUri;
@@ -1744,7 +1744,7 @@ ol.format.KML.prototype.readSharedStyleMap_ = function(node, objectStack) {
   goog.asserts.assert(node.localName == 'StyleMap',
       'localName should be StyleMap');
   var id = node.getAttribute('id');
-  if (goog.isNull(id)) {
+  if (id === null) {
     return;
   }
   var styleMapValue = ol.format.KML.readStyleMapValue_(node, objectStack);
@@ -1836,8 +1836,7 @@ ol.format.KML.prototype.readFeaturesFromNode = function(node, opt_options) {
   } else if (localName == 'kml') {
     features = [];
     var n;
-    for (n = node.firstElementChild; !goog.isNull(n);
-         n = n.nextElementSibling) {
+    for (n = node.firstElementChild; n; n = n.nextElementSibling) {
       var fs = this.readFeaturesFromNode(n, opt_options);
       if (fs) {
         goog.array.extend(features, fs);
@@ -1878,7 +1877,7 @@ ol.format.KML.prototype.readName = function(source) {
  */
 ol.format.KML.prototype.readNameFromDocument = function(doc) {
   var n;
-  for (n = doc.firstChild; !goog.isNull(n); n = n.nextSibling) {
+  for (n = doc.firstChild; n; n = n.nextSibling) {
     if (n.nodeType == goog.dom.NodeType.ELEMENT) {
       var name = this.readNameFromNode(n);
       if (name) {
@@ -1896,13 +1895,13 @@ ol.format.KML.prototype.readNameFromDocument = function(doc) {
  */
 ol.format.KML.prototype.readNameFromNode = function(node) {
   var n;
-  for (n = node.firstElementChild; !goog.isNull(n); n = n.nextElementSibling) {
+  for (n = node.firstElementChild; n; n = n.nextElementSibling) {
     if (ol.array.includes(ol.format.KML.NAMESPACE_URIS_, n.namespaceURI) &&
         n.localName == 'name') {
       return ol.format.XSD.readString(n);
     }
   }
-  for (n = node.firstElementChild; !goog.isNull(n); n = n.nextElementSibling) {
+  for (n = node.firstElementChild; n; n = n.nextElementSibling) {
     var localName = ol.xml.getLocalName(n);
     if (ol.array.includes(ol.format.KML.NAMESPACE_URIS_, n.namespaceURI) &&
         (localName == 'Document' ||
@@ -1950,7 +1949,7 @@ ol.format.KML.prototype.readNetworkLinks = function(source) {
  */
 ol.format.KML.prototype.readNetworkLinksFromDocument = function(doc) {
   var n, networkLinks = [];
-  for (n = doc.firstChild; !goog.isNull(n); n = n.nextSibling) {
+  for (n = doc.firstChild; n; n = n.nextSibling) {
     if (n.nodeType == goog.dom.NodeType.ELEMENT) {
       goog.array.extend(networkLinks, this.readNetworkLinksFromNode(n));
     }
@@ -1965,7 +1964,7 @@ ol.format.KML.prototype.readNetworkLinksFromDocument = function(doc) {
  */
 ol.format.KML.prototype.readNetworkLinksFromNode = function(node) {
   var n, networkLinks = [];
-  for (n = node.firstElementChild; !goog.isNull(n); n = n.nextElementSibling) {
+  for (n = node.firstElementChild; n; n = n.nextElementSibling) {
     if (ol.array.includes(ol.format.KML.NAMESPACE_URIS_, n.namespaceURI) &&
         n.localName == 'NetworkLink') {
       var obj = ol.xml.pushParseAndPop({}, ol.format.KML.NETWORK_LINK_PARSERS_,
@@ -1973,7 +1972,7 @@ ol.format.KML.prototype.readNetworkLinksFromNode = function(node) {
       networkLinks.push(obj);
     }
   }
-  for (n = node.firstElementChild; !goog.isNull(n); n = n.nextElementSibling) {
+  for (n = node.firstElementChild; n; n = n.nextElementSibling) {
     var localName = ol.xml.getLocalName(n);
     if (ol.array.includes(ol.format.KML.NAMESPACE_URIS_, n.namespaceURI) &&
         (localName == 'Document' ||
@@ -2110,20 +2109,18 @@ ol.format.KML.writeIconStyle_ = function(node, style, objectStack) {
     'href': src
   };
 
-  if (!goog.isNull(size)) {
+  if (size) {
     iconProperties['w'] = size[0];
     iconProperties['h'] = size[1];
     var anchor = style.getAnchor(); // top-left
     var origin = style.getOrigin(); // top-left
 
-    if (!goog.isNull(origin) && !goog.isNull(iconImageSize) &&
-        origin[0] !== 0 && origin[1] !== size[1]) {
+    if (origin && iconImageSize && origin[0] !== 0 && origin[1] !== size[1]) {
       iconProperties['x'] = origin[0];
       iconProperties['y'] = iconImageSize[1] - (origin[1] + size[1]);
     }
 
-    if (!goog.isNull(anchor) &&
-        anchor[0] !== 0 && anchor[1] !== size[1]) {
+    if (anchor && anchor[0] !== 0 && anchor[1] !== size[1]) {
       var /** @type {ol.format.KMLVec2_} */ hotSpot = {
         x: anchor[0],
         xunits: ol.style.IconAnchorUnits.PIXELS,
@@ -2164,7 +2161,7 @@ ol.format.KML.writeLabelStyle_ = function(node, style, objectStack) {
   var /** @type {ol.xml.NodeStackItem} */ context = {node: node};
   var properties = {};
   var fill = style.getFill();
-  if (!goog.isNull(fill)) {
+  if (fill) {
     properties['color'] = fill.getColor();
   }
   var scale = style.getScale();
@@ -2279,10 +2276,10 @@ ol.format.KML.writePlacemark_ = function(node, feature, objectStack) {
     // FIXME the styles returned by the style function are supposed to be
     // resolution-independent here
     var styles = styleFunction.call(feature, 0);
-    if (!goog.isNull(styles) && styles.length > 0) {
+    if (styles && styles.length > 0) {
       properties['Style'] = styles[0];
       var textStyle = styles[0].getText();
-      if (!goog.isNull(textStyle)) {
+      if (textStyle) {
         properties['name'] = textStyle.getText();
       }
     }
@@ -2392,16 +2389,16 @@ ol.format.KML.writeStyle_ = function(node, style, objectStack) {
   var strokeStyle = style.getStroke();
   var imageStyle = style.getImage();
   var textStyle = style.getText();
-  if (!goog.isNull(imageStyle)) {
+  if (imageStyle) {
     properties['IconStyle'] = imageStyle;
   }
-  if (!goog.isNull(textStyle)) {
+  if (textStyle) {
     properties['LabelStyle'] = textStyle;
   }
-  if (!goog.isNull(strokeStyle)) {
+  if (strokeStyle) {
     properties['LineStyle'] = strokeStyle;
   }
-  if (!goog.isNull(fillStyle)) {
+  if (fillStyle) {
     properties['PolyStyle'] = fillStyle;
   }
   var parentNode = objectStack[objectStack.length - 1].node;
diff --git a/src/ol/format/owsformat.js b/src/ol/format/owsformat.js
index 1ebd2df650..701abb25b2 100644
--- a/src/ol/format/owsformat.js
+++ b/src/ol/format/owsformat.js
@@ -26,7 +26,7 @@ goog.inherits(ol.format.OWS, ol.format.XML);
 ol.format.OWS.prototype.readFromDocument = function(doc) {
   goog.asserts.assert(doc.nodeType == goog.dom.NodeType.DOCUMENT,
       'doc.nodeType should be DOCUMENT');
-  for (var n = doc.firstChild; !goog.isNull(n); n = n.nextSibling) {
+  for (var n = doc.firstChild; n; n = n.nextSibling) {
     if (n.nodeType == goog.dom.NodeType.ELEMENT) {
       return this.readFromNode(n);
     }
diff --git a/src/ol/format/topojsonformat.js b/src/ol/format/topojsonformat.js
index ae275793cd..1a4cdb87b8 100644
--- a/src/ol/format/topojsonformat.js
+++ b/src/ol/format/topojsonformat.js
@@ -97,7 +97,7 @@ ol.format.TopoJSON.concatenateArcs_ = function(indices, arcs) {
  */
 ol.format.TopoJSON.readPointGeometry_ = function(object, scale, translate) {
   var coordinates = object.coordinates;
-  if (!goog.isNull(scale) && !goog.isNull(translate)) {
+  if (scale && translate) {
     ol.format.TopoJSON.transformVertex_(coordinates, scale, translate);
   }
   return new ol.geom.Point(coordinates);
@@ -117,7 +117,7 @@ ol.format.TopoJSON.readMultiPointGeometry_ = function(object, scale,
     translate) {
   var coordinates = object.coordinates;
   var i, ii;
-  if (!goog.isNull(scale) && !goog.isNull(translate)) {
+  if (scale && translate) {
     for (i = 0, ii = coordinates.length; i < ii; ++i) {
       ol.format.TopoJSON.transformVertex_(coordinates[i], scale, translate);
     }
diff --git a/src/ol/format/wfsformat.js b/src/ol/format/wfsformat.js
index 63dd77bfb1..10b463b828 100644
--- a/src/ol/format/wfsformat.js
+++ b/src/ol/format/wfsformat.js
@@ -196,7 +196,7 @@ ol.format.WFS.prototype.readFeatureCollectionMetadataFromDocument =
     function(doc) {
   goog.asserts.assert(doc.nodeType == goog.dom.NodeType.DOCUMENT,
       'doc.nodeType should be DOCUMENT');
-  for (var n = doc.firstChild; !goog.isNull(n); n = n.nextSibling) {
+  for (var n = doc.firstChild; n; n = n.nextSibling) {
     if (n.nodeType == goog.dom.NodeType.ELEMENT) {
       return this.readFeatureCollectionMetadataFromNode(n);
     }
@@ -337,7 +337,7 @@ ol.format.WFS.TRANSACTION_RESPONSE_PARSERS_ = {
 ol.format.WFS.prototype.readTransactionResponseFromDocument = function(doc) {
   goog.asserts.assert(doc.nodeType == goog.dom.NodeType.DOCUMENT,
       'doc.nodeType should be DOCUMENT');
-  for (var n = doc.firstChild; !goog.isNull(n); n = n.nextSibling) {
+  for (var n = doc.firstChild; n; n = n.nextSibling) {
     if (n.nodeType == goog.dom.NodeType.ELEMENT) {
       return this.readTransactionResponseFromNode(n);
     }
@@ -750,7 +750,7 @@ ol.format.WFS.prototype.readProjection;
 ol.format.WFS.prototype.readProjectionFromDocument = function(doc) {
   goog.asserts.assert(doc.nodeType == goog.dom.NodeType.DOCUMENT,
       'doc.nodeType should be a DOCUMENT');
-  for (var n = doc.firstChild; !goog.isNull(n); n = n.nextSibling) {
+  for (var n = doc.firstChild; n; n = n.nextSibling) {
     if (n.nodeType == goog.dom.NodeType.ELEMENT) {
       return this.readProjectionFromNode(n);
     }
@@ -771,8 +771,7 @@ ol.format.WFS.prototype.readProjectionFromNode = function(node) {
   if (node.firstElementChild &&
       node.firstElementChild.firstElementChild) {
     node = node.firstElementChild.firstElementChild;
-    for (var n = node.firstElementChild; !goog.isNull(n);
-        n = n.nextElementSibling) {
+    for (var n = node.firstElementChild; n; n = n.nextElementSibling) {
       if (!(n.childNodes.length === 0 ||
           (n.childNodes.length === 1 &&
           n.firstChild.nodeType === 3))) {
diff --git a/src/ol/format/wmscapabilitiesformat.js b/src/ol/format/wmscapabilitiesformat.js
index d3c5a38d0a..5612b93d13 100644
--- a/src/ol/format/wmscapabilitiesformat.js
+++ b/src/ol/format/wmscapabilitiesformat.js
@@ -50,7 +50,7 @@ ol.format.WMSCapabilities.prototype.read;
 ol.format.WMSCapabilities.prototype.readFromDocument = function(doc) {
   goog.asserts.assert(doc.nodeType == goog.dom.NodeType.DOCUMENT,
       'doc.nodeType should be DOCUMENT');
-  for (var n = doc.firstChild; !goog.isNull(n); n = n.nextSibling) {
+  for (var n = doc.firstChild; n; n = n.nextSibling) {
     if (n.nodeType == goog.dom.NodeType.ELEMENT) {
       return this.readFromNode(n);
     }
diff --git a/src/ol/format/wmtscapabilitiesformat.js b/src/ol/format/wmtscapabilitiesformat.js
index 11cc05ec4d..628b4810b0 100644
--- a/src/ol/format/wmtscapabilitiesformat.js
+++ b/src/ol/format/wmtscapabilitiesformat.js
@@ -50,7 +50,7 @@ ol.format.WMTSCapabilities.prototype.read;
 ol.format.WMTSCapabilities.prototype.readFromDocument = function(doc) {
   goog.asserts.assert(doc.nodeType == goog.dom.NodeType.DOCUMENT,
       'doc.nodeType should be DOCUMENT');
-  for (var n = doc.firstChild; !goog.isNull(n); n = n.nextSibling) {
+  for (var n = doc.firstChild; n; n = n.nextSibling) {
     if (n.nodeType == goog.dom.NodeType.ELEMENT) {
       return this.readFromNode(n);
     }
diff --git a/src/ol/format/xmlfeatureformat.js b/src/ol/format/xmlfeatureformat.js
index 8c1d6baa15..dbc930e6af 100644
--- a/src/ol/format/xmlfeatureformat.js
+++ b/src/ol/format/xmlfeatureformat.js
@@ -107,7 +107,7 @@ ol.format.XMLFeature.prototype.readFeaturesFromDocument = function(
   /** @type {Array.<ol.Feature>} */
   var features = [];
   var n;
-  for (n = doc.firstChild; !goog.isNull(n); n = n.nextSibling) {
+  for (n = doc.firstChild; n; n = n.nextSibling) {
     if (n.nodeType == goog.dom.NodeType.ELEMENT) {
       goog.array.extend(features, this.readFeaturesFromNode(n, opt_options));
     }