diff --git a/externs/webgl-debug.js b/externs/webgl-debug.js
new file mode 100644
index 0000000000..33fa2112aa
--- /dev/null
+++ b/externs/webgl-debug.js
@@ -0,0 +1,55 @@
+/**
+ * @externs
+ */
+
+
+
+/**
+ * @constructor
+ * @extends {WebGLRenderingContext}
+ */
+var WebGLDebugRenderingContext = function() {};
+
+
+/**
+ * @type {Object}
+ */
+var WebGLDebugUtils = {};
+
+
+/**
+ * @param {number} glEnum GL enum.
+ * @return {string} String.
+ */
+WebGLDebugUtils.glEnumToString = function(glEnum) {
+  return '';
+};
+
+
+/**
+ * @param {string} functionName Function name.
+ * @param {Array} args Args.
+ * @return {string} String.
+ */
+WebGLDebugUtils.glFunctionArgsToString = function(functionName, args) {
+  return '';
+};
+
+
+/**
+ * @param {WebGLRenderingContext} context Context.
+ */
+WebGLDebugUtils.init = function(context) {
+};
+
+
+/**
+ * @param {WebGLRenderingContext} context Context.
+ * @param {Function=} opt_onErrorFunc On error function.
+ * @param {Function=} opt_onFunc On function.
+ * @return {WebGLDebugRenderingContext} Context.
+ */
+WebGLDebugUtils.makeDebugContext = function(
+    context, opt_onErrorFunc, opt_onFunc) {
+  return null;
+};
diff --git a/main.json b/main.json
index 086aa8c0d6..34174c46bc 100644
--- a/main.json
+++ b/main.json
@@ -16,7 +16,8 @@
   },
 
   "externs": [
-    "externs/geojson.js"
+    "externs/geojson.js",
+    "externs/webgl-debug.js"
   ],
 
   "mode": "ADVANCED",