diff --git a/lib/OpenLayers/Format/GPX.js b/lib/OpenLayers/Format/GPX.js
index c6a67f9953..f3f0fce313 100644
--- a/lib/OpenLayers/Format/GPX.js
+++ b/lib/OpenLayers/Format/GPX.js
@@ -57,11 +57,20 @@ OpenLayers.Format.GPX = OpenLayers.Class(OpenLayers.Format.XML, {
     extractAttributes: true,
 
     /**
-     * APIProperty: gpxns
-     * {String} GPX namespace to use. Defaults to
-     *   "http://www.topografix.com/GPX/1/1"
+     * Property: namespaces
+     * {Object} Mapping of namespace aliases to namespace URIs.
      */
-    gpxns: "http://www.topografix.com/GPX/1/1",
+    namespaces: {
+        gpx: "http://www.topografix.com/GPX/1/1",
+        xsi: "http://www.w3.org/2001/XMLSchema-instance"
+    },
+
+    /**
+     * Property: schemaLocation
+     * {String} Schema location. Defaults to
+     *  "http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd"
+     */
+    schemaLocation: "http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd",
     
     /**
      * Constructor: OpenLayers.Format.GPX
@@ -207,17 +216,20 @@ OpenLayers.Format.GPX = OpenLayers.Class(OpenLayers.Format.XML, {
      *      add to the gpx. Supported keys are 'name', 'desc', 'author'.
      */
     write: function(features, metadata) {
-        var gpx;
         features = OpenLayers.Util.isArray(features) ?
             features : [features];
-        gpx = this.createElementNS(this.gpxns, "gpx");
+        var gpx = this.createElementNSPlus("gpx:gpx");
+        gpx.setAttribute("version", "1.1");
+        this.setAttributes(gpx, {
+            "xsi:schemaLocation": this.schemaLocation
+        });
 
-        for(var i=0, len=features.length; i<len; i++) {
-            gpx.appendChild(this.buildFeatureNode(features[i]));
-        }
         if (metadata && typeof metadata == 'object') {
             gpx.appendChild(this.buildMetadataNode(metadata));
         }
+        for(var i=0, len=features.length; i<len; i++) {
+            gpx.appendChild(this.buildFeatureNode(features[i]));
+        }
         return OpenLayers.Format.XML.prototype.write.apply(this, [gpx]);
     },
 
@@ -230,11 +242,11 @@ OpenLayers.Format.GPX = OpenLayers.Class(OpenLayers.Format.XML, {
      */
     buildMetadataNode: function(metadata) {
         var types = ['name', 'desc', 'author'],
-            node = this.createElementNS(this.gpxns, 'metadata');
+            node = this.createElementNSPlus('gpx:metadata');
         for (var i=0; i < types.length; i++) {
             var type = types[i];
             if (metadata[type]) {
-                var n = this.createElementNS(this.gpxns, type);
+                var n = this.createElementNSPlus("gpx:" + type);
                 n.appendChild(this.createTextNode(metadata[type]));
                 node.appendChild(n);
             }
@@ -263,7 +275,7 @@ OpenLayers.Format.GPX = OpenLayers.Class(OpenLayers.Format.XML, {
             var wpt = this.buildWptNode(feature);
             return wpt;
         } else {
-            var trkNode = this.createElementNS(this.gpxns, "trk");
+            var trkNode = this.createElementNSPlus("gpx:trk");
             this.appendAttributesNode(trkNode, feature);
             var trkSegNodes = this.buildTrkSegNode(geometry);
             trkSegNodes = OpenLayers.Util.isArray(trkSegNodes) ?
@@ -291,7 +303,7 @@ OpenLayers.Format.GPX = OpenLayers.Class(OpenLayers.Format.XML, {
             nodes;
         if (geometry.CLASS_NAME == "OpenLayers.Geometry.LineString" ||
             geometry.CLASS_NAME == "OpenLayers.Geometry.LinearRing") {
-            node = this.createElementNS(this.gpxns, "trkseg");
+            node = this.createElementNSPlus("gpx:trkseg");
             for (i = 0, len=geometry.components.length; i < len; i++) {
                 point = geometry.components[i];
                 node.appendChild(this.buildTrkPtNode(point));
@@ -317,7 +329,7 @@ OpenLayers.Format.GPX = OpenLayers.Class(OpenLayers.Format.XML, {
      * {DOMElement} A trkpt node
      */
     buildTrkPtNode: function(point) {
-        var node = this.createElementNS(this.gpxns, "trkpt");
+        var node = this.createElementNSPlus("gpx:trkpt");
         node.setAttribute("lon", point.x);
         node.setAttribute("lat", point.y);
         return node;
@@ -334,7 +346,7 @@ OpenLayers.Format.GPX = OpenLayers.Class(OpenLayers.Format.XML, {
      * {DOMElement} A wpt node
      */
     buildWptNode: function(feature) {
-        var node = this.createElementNS(this.gpxns, "wpt");
+        var node = this.createElementNSPlus("gpx:wpt");
         node.setAttribute("lon", feature.geometry.x);
         node.setAttribute("lat", feature.geometry.y);
         this.appendAttributesNode(node, feature);
@@ -350,11 +362,11 @@ OpenLayers.Format.GPX = OpenLayers.Class(OpenLayers.Format.XML, {
      * feature - {<OpenLayers.Feature.Vector>}
      */
     appendAttributesNode: function(node, feature) {
-        var name = this.createElementNS(this.gpxns, 'name');
+        var name = this.createElementNSPlus('gpx:name');
         name.appendChild(this.createTextNode(
             feature.attributes.name || feature.id));
         node.appendChild(name);
-        var desc = this.createElementNS(this.gpxns, 'desc');
+        var desc = this.createElementNSPlus('gpx:desc');
         desc.appendChild(this.createTextNode(
             feature.attributes.description || this.defaultDesc));
         node.appendChild(desc);
diff --git a/notes/2.12.md b/notes/2.12.md
index a02c465a7a..2182009676 100644
--- a/notes/2.12.md
+++ b/notes/2.12.md
@@ -22,6 +22,10 @@ People can override this rule to use other transition settings. To remove tile a
 
 # Behavior Changes from Past Releases
 
+## GPX API change
+
+The `gpxns` API property has been removed. The GPX namespace is now defined in the `namespaces` property but is not intended to be overriden.
+
 ## Function return values
 
 [Previously][prev] a few functions in the library displayed error messages and returned `undefined`, `null` or `false` if the parameters passed in were bad. In 2.12 these functions now just throw an error/exception. People relying on return values to know if a function call is successful may need to change their code. Here are the modified functions:
diff --git a/tests/Format/GPX.html b/tests/Format/GPX.html
index 2b88e7a9de..6a86ca6774 100644
--- a/tests/Format/GPX.html
+++ b/tests/Format/GPX.html
@@ -46,7 +46,7 @@
             new OpenLayers.Feature.Vector(point2, {name: 'foo', description: 'bar'})
         ];
         var data = parser.write(features);
-        t.xml_eq(data, '<?xml version="1.0" encoding="ISO-8859-1"?><gpx xmlns="http://www.topografix.com/GPX/1/1"><wpt lon="-111.04" lat="45.68"><name>foo</name><desc>bar</desc></wpt><wpt lon="-112.04" lat="45.68"><name>foo</name><desc>bar</desc></wpt></gpx>', 'GPX serializes points correctly');
+        t.xml_eq(data, '<gpx xmlns="http://www.topografix.com/GPX/1/1" version="1.1" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><wpt lon="-111.04" lat="45.68"><name>foo</name><desc>bar</desc></wpt><wpt lon="-112.04" lat="45.68"><name>foo</name><desc>bar</desc></wpt></gpx>', 'GPX serializes points correctly');
     }
     function test_Format_GPX_serialize_line(t) { 
         t.plan(1);
@@ -58,7 +58,7 @@
         var line = new OpenLayers.Geometry.LineString([point, point2]);
         var f = new OpenLayers.Feature.Vector(line, {name: 'foo', description: 'bar'});
         var data = parser.write(f);
-        t.xml_eq(data, '<?xml version="1.0" encoding="ISO-8859-1"?><gpx xmlns="http://www.topografix.com/GPX/1/1"><trk><name>foo</name><desc>bar</desc><trkseg><trkpt lon="-111.04" lat="45.68"/><trkpt lon="-112.04" lat="45.68"/></trkseg></trk></gpx>', 'GPX serializes line correctly');
+        t.xml_eq(data, '<gpx xmlns="http://www.topografix.com/GPX/1/1" version="1.1" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><trk><name>foo</name><desc>bar</desc><trkseg><trkpt lon="-111.04" lat="45.68"/><trkpt lon="-112.04" lat="45.68"/></trkseg></trk></gpx>', 'GPX serializes line correctly');
     }
     function test_Format_GPX_serialize_lines(t) { 
         t.plan(1);
@@ -74,7 +74,7 @@
         var f = new OpenLayers.Feature.Vector(line, {name: 'foo', description: 'bar'});
         var f2 = new OpenLayers.Feature.Vector(line2, {name: 'dude', description: 'truite'});
         var data = parser.write([f, f2]);
-        t.xml_eq(data, '<?xml version="1.0" encoding="ISO-8859-1"?><gpx xmlns="http://www.topografix.com/GPX/1/1"><trk><name>foo</name><desc>bar</desc><trkseg><trkpt lon="-111.04" lat="45.68"/><trkpt lon="-112.04" lat="45.68"/></trkseg></trk><trk><name>dude</name><desc>truite</desc><trkseg><trkpt lon="1" lat="2"/><trkpt lon="3" lat="4"/></trkseg></trk></gpx>', 'GPX serializes lines correctly');
+        t.xml_eq(data, '<gpx xmlns="http://www.topografix.com/GPX/1/1" version="1.1" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><trk><name>foo</name><desc>bar</desc><trkseg><trkpt lon="-111.04" lat="45.68"/><trkpt lon="-112.04" lat="45.68"/></trkseg></trk><trk><name>dude</name><desc>truite</desc><trkseg><trkpt lon="1" lat="2"/><trkpt lon="3" lat="4"/></trkseg></trk></gpx>', 'GPX serializes lines correctly');
     }
     function test_Format_GPX_serialize_multiline(t) { 
         t.plan(1);
@@ -90,7 +90,7 @@
         var multiline = new OpenLayers.Geometry.MultiLineString([line, line2]);
         var f = new OpenLayers.Feature.Vector(multiline, {name: 'foo', description: 'bar'});
         var data = parser.write([f]);
-        t.xml_eq(data, '<?xml version="1.0" encoding="ISO-8859-1"?><gpx xmlns="http://www.topografix.com/GPX/1/1"><trk><name>foo</name><desc>bar</desc><trkseg><trkpt lon="-111.04" lat="45.68"/><trkpt lon="-112.04" lat="45.68"/></trkseg><trkseg><trkpt lon="1" lat="2"/><trkpt lon="3" lat="4"/></trkseg></trk></gpx>', 'GPX serializes multiline correctly');
+        t.xml_eq(data, '<gpx xmlns="http://www.topografix.com/GPX/1/1" version="1.1" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><trk><name>foo</name><desc>bar</desc><trkseg><trkpt lon="-111.04" lat="45.68"/><trkpt lon="-112.04" lat="45.68"/></trkseg><trkseg><trkpt lon="1" lat="2"/><trkpt lon="3" lat="4"/></trkseg></trk></gpx>', 'GPX serializes multiline correctly');
     }
     function test_Format_GPX_serialize_polygon(t) { 
         t.plan(1);
@@ -103,7 +103,7 @@
         var polygon = new OpenLayers.Geometry.Polygon([linearRing]);
         var f = new OpenLayers.Feature.Vector(polygon, {name: 'foo', description: 'bar'});
         var data = parser.write([f]);
-        t.xml_eq(data, '<?xml version="1.0" encoding="ISO-8859-1"?><gpx xmlns="http://www.topografix.com/GPX/1/1"><trk><name>foo</name><desc>bar</desc><trkseg><trkpt lon="-111.04" lat="45.68"/><trkpt lon="-112.04" lat="45.68"/><trkpt lon="-111.04" lat="45.68"/></trkseg></trk></gpx>', 'GPX serializes polygon correctly');
+        t.xml_eq(data, '<gpx xmlns="http://www.topografix.com/GPX/1/1" version="1.1" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><trk><name>foo</name><desc>bar</desc><trkseg><trkpt lon="-111.04" lat="45.68"/><trkpt lon="-112.04" lat="45.68"/><trkpt lon="-111.04" lat="45.68"/></trkseg></trk></gpx>', 'GPX serializes polygon correctly');
     }
     function test_Format_GPX_serialize_metadata(t) { 
         t.plan(1);
@@ -111,7 +111,7 @@
         var parser = new OpenLayers.Format.GPX();
 
         var data = parser.write([], {name: 'foo', desc: 'bar'});
-        t.xml_eq(data, '<?xml version="1.0" encoding="ISO-8859-1"?><gpx xmlns="http://www.topografix.com/GPX/1/1"><metadata><name>foo</name><desc>bar</desc></metadata></gpx>', 'GPX serializes metadata correctly');
+        t.xml_eq(data, '<gpx xmlns="http://www.topografix.com/GPX/1/1" version="1.1" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><metadata><name>foo</name><desc>bar</desc></metadata></gpx>', 'GPX serializes metadata correctly');
     }
     </script> 
 </head>