diff --git a/src/ol/format/gmlformat.js b/src/ol/format/gmlformat.js
index 6c3d3935c5..b98ad70adc 100644
--- a/src/ol/format/gmlformat.js
+++ b/src/ol/format/gmlformat.js
@@ -7,6 +7,7 @@ goog.require('goog.dom.NodeType');
 goog.require('goog.object');
 goog.require('goog.string');
 goog.require('ol.Feature');
+goog.require('ol.array');
 goog.require('ol.extent');
 goog.require('ol.format.XMLFeature');
 goog.require('ol.format.XSD');
@@ -576,7 +577,7 @@ ol.format.GML.readPolygon_ = function(node, objectStack) {
     var ends = [flatCoordinates.length];
     var i, ii;
     for (i = 1, ii = flatLinearRings.length; i < ii; ++i) {
-      goog.array.extend(flatCoordinates, flatLinearRings[i]);
+      ol.array.safeExtend(flatCoordinates, flatLinearRings[i]);
       ends.push(flatCoordinates.length);
     }
     polygon.setFlatCoordinates(
@@ -607,7 +608,7 @@ ol.format.GML.readSurface_ = function(node, objectStack) {
     var ends = [flatCoordinates.length];
     var i, ii;
     for (i = 1, ii = flatLinearRings.length; i < ii; ++i) {
-      goog.array.extend(flatCoordinates, flatLinearRings[i]);
+      ol.array.safeExtend(flatCoordinates, flatLinearRings[i]);
       ends.push(flatCoordinates.length);
     }
     polygon.setFlatCoordinates(