diff --git a/CHANGES.md b/CHANGES.md
index 99397a1266c3..bbe0639f423f 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -2,6 +2,7 @@ Change Log
 ==========
 ### 1.39 - 2017-11-01
 
+* Added function that inserts missing namespace declarations into KML files. [#5860](https://github.com/AnalyticalGraphicsInc/cesium/pull/5860)
 * Added support for the layer.json `parentUrl` property in `CesiumTerrainProvider` to allow for compositing of tilesets.
 * Fixed a bug that caused KML ground overlays to appear distorted when rotation was applied. [#5914](https://github.com/AnalyticalGraphicsInc/cesium/issues/5914)
 * Adds `invertClassification` and `invertClassificationColor` to `Scene`. When `invertClassification` is `true`, any 3D Tiles geometry that is not classified by a `ClassificationPrimitive` or `GroundPrimitive` will have its color multiplied by `invertClassificationColor`. [#5836](https://github.com/AnalyticalGraphicsInc/cesium/pull/5836)
diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
index d1476a7c992d..a9e5f51b5e3e 100644
--- a/CONTRIBUTORS.md
+++ b/CONTRIBUTORS.md
@@ -93,6 +93,7 @@ See [CONTRIBUTING.md](CONTRIBUTING.md) for details on how to contribute to Cesiu
 * [Logilab](https://www.logilab.fr/)
    * [Florent Cayré](https://github.com/fcayre/)
 * [Novetta](http://www.novetta.com/)
+   * [Natanael Rivera](https://github.com/nrivera-Novetta/)
    * [Justin Burr](https://github.com/jburr-nc/)
 
 ## [Individual CLA](Documentation/Contributors/CLAs/individual-cla-agi-v1.0.txt)
diff --git a/Source/DataSources/KmlDataSource.js b/Source/DataSources/KmlDataSource.js
index 0da6c9ea118a..4a574002a6c2 100644
--- a/Source/DataSources/KmlDataSource.js
+++ b/Source/DataSources/KmlDataSource.js
@@ -255,6 +255,33 @@ define([
         return deferred.promise;
     }
 
+    function insertNamespaces(text) {
+        var namespaceMap = {
+            xsi : 'http://www.w3.org/2001/XMLSchema-instance'
+        };
+        var firstPart, lastPart, reg, declaration;
+
+        for (var key in namespaceMap) {
+            if (namespaceMap.hasOwnProperty(key)) {
+                reg = RegExp('[< ]' + key + ':');
+                declaration = 'xmlns:' + key + '=';
+                if (reg.test(text) && text.indexOf(declaration) === -1) {
+                    if (!defined(firstPart)) {
+                        firstPart = text.substr(0, text.indexOf('<kml') + 4);
+                        lastPart = text.substr(firstPart.length);
+                    }
+                    firstPart += ' ' + declaration + '"' + namespaceMap[key] + '"';
+                }
+            }
+        }
+
+        if (defined(firstPart)) {
+            text = firstPart + lastPart;
+        }
+
+        return text;
+    }
+
     function loadXmlFromZip(reader, entry, uriResolver, deferred) {
         entry.getData(new zip.TextWriter(), function(text) {
             uriResolver.kml = parser.parseFromString(text, 'application/xml');
@@ -2324,6 +2351,9 @@ define([
                             //There's no official way to validate if a parse was successful.
                             //The following check detects the error on various browsers.
 
+                            //Insert missing namespaces
+                            text = insertNamespaces(text);
+
                             //IE raises an exception
                             var kml;
                             var error;
diff --git a/Specs/Data/KML/undeclaredNamespaces.kml b/Specs/Data/KML/undeclaredNamespaces.kml
new file mode 100644
index 000000000000..d1107f9c05c3
--- /dev/null
+++ b/Specs/Data/KML/undeclaredNamespaces.kml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<kml xmlns="http://www.opengis.net/kml/2.2">
+<Document xsi:schemaLocation="http://www.opengis.net/kml/2.2 http://schemas.opengis.net/kml/2.2.0/ogckml22.xsd http://www.google.com/kml/ext/2.2 http://code.google.com/apis/kml/schema/kml22gx.xsd">
+    <Placemark>
+        <Style>
+            <IconStyle>
+              <Icon>
+                  <href>image.png</href>
+              </Icon>
+            </IconStyle>
+        </Style>
+        <description><![CDATA[image.png <a href="./image.png">image.png</a><img src="image.png"/>]]></description>
+        <Point>
+            <coordinates>1,2,3</coordinates>
+        </Point>
+    </Placemark>
+</Document>
+</kml>
diff --git a/Specs/DataSources/KmlDataSourceSpec.js b/Specs/DataSources/KmlDataSourceSpec.js
index 93d70d10f28e..acaacb86430c 100644
--- a/Specs/DataSources/KmlDataSourceSpec.js
+++ b/Specs/DataSources/KmlDataSourceSpec.js
@@ -244,6 +244,14 @@ defineSuite([
         });
     });
 
+    it('load inserts missing namespace declaration', function() {
+        var dataSource = new KmlDataSource(options);
+        return dataSource.load('Data/KML/undeclaredNamespaces.kml').then(function(source) {
+            expect(source).toBe(dataSource);
+            expect(source.entities.values.length).toEqual(1);
+        });
+    });
+
     it('load rejects nonexistent URL', function() {
         return KmlDataSource.load('test.invalid', options).otherwise(function(e) {
             expect(e).toBeInstanceOf(RequestErrorEvent);