diff --git a/src/ol/source/wmssource.js b/src/ol/source/wmssource.js
index 68c5cbe026..48c5729c52 100644
--- a/src/ol/source/wmssource.js
+++ b/src/ol/source/wmssource.js
@@ -34,8 +34,8 @@ ol.source.wms.getUrl =
 
   var axisOrientation = projection.getAxisOrientation();
   var bboxValues = (wms13 && axisOrientation.substr(0, 2) == 'ne') ?
-      [extent.minY, extent.minX, extent.maxY, extent.maxX] :
-      [extent.minX, extent.minY, extent.maxX, extent.maxY];
+      [extent[2], extent[0], extent[3], extent[1]] :
+      [extent[0], extent[2], extent[1], extent[3]];
   baseParams['BBOX'] = bboxValues.join(',');
 
   return goog.uri.utils.appendParamsFromMap(baseUrl, baseParams);
diff --git a/test/spec/ol/source/wmssource.test.js b/test/spec/ol/source/wmssource.test.js
index 9c9f74d786..f9b0bac46e 100644
--- a/test/spec/ol/source/wmssource.test.js
+++ b/test/spec/ol/source/wmssource.test.js
@@ -5,8 +5,7 @@ describe('ol.source.wms', function() {
   describe('ol.source.wms.getUrl', function() {
     it('creates expected URL', function() {
       var epsg3857 = ol.projection.get('EPSG:3857');
-      var extent = new ol.Extent(
-          -20037508.342789244, -20037508.342789244, 0, 0);
+      var extent = [-20037508.342789244, 0, -20037508.342789244, 0];
       var expected = 'http://wms?SERVICE=WMS&VERSION=1.3.0&REQUEST=' +
           'GetMap&FORMAT=image%2Fpng&TRANSPARENT=true&WIDTH=256&HEIGHT=256&' +
           'foo=bar&STYLES=&CRS=EPSG%3A3857&BBOX=' +
@@ -17,7 +16,7 @@ describe('ol.source.wms', function() {
     });
     it('creates expected URL respecting axis orientation', function() {
       var epsg4326 = ol.projection.get('EPSG:4326');
-      var extent = new ol.Extent(-180, -90, 0, 90);
+      var extent = [-180, 0, -90, 90];
       var expected = 'http://wms?SERVICE=WMS&VERSION=1.3.0&REQUEST=' +
           'GetMap&FORMAT=image%2Fpng&TRANSPARENT=true&WIDTH=256&HEIGHT=256&' +
           'foo=bar&STYLES=&CRS=EPSG%3A4326&BBOX=-90%2C-180%2C90%2C0';
@@ -30,7 +29,6 @@ describe('ol.source.wms', function() {
 });
 
 
-goog.require('ol.Extent');
 goog.require('ol.Size');
 goog.require('ol.projection');
 goog.require('ol.source.wms');