diff --git a/core/src/main/java/com/axellience/vuegwt/core/client/VueGWT.js b/core/src/main/java/com/axellience/vuegwt/core/client/VueGWT.js
index f9870433..514a7c61 100644
--- a/core/src/main/java/com/axellience/vuegwt/core/client/VueGWT.js
+++ b/core/src/main/java/com/axellience/vuegwt/core/client/VueGWT.js
@@ -1,7 +1,7 @@
 goog.provide("vuegwt");
 
 /** @define {string} */
-goog.define("vuegwt.environment", "production");
+vuegwt.environment = goog.define("vuegwt.environment", "production");
 
 /** @define {string} */
-goog.define("superdevmode", "off");
\ No newline at end of file
+var superdevmode = goog.define("superdevmode", "off");
\ No newline at end of file
diff --git a/core/src/main/java/com/axellience/vuegwt/core/client/customelement/VueCustomElement.js b/core/src/main/java/com/axellience/vuegwt/core/client/customelement/VueCustomElement.js
new file mode 100644
index 00000000..f5f5b068
--- /dev/null
+++ b/core/src/main/java/com/axellience/vuegwt/core/client/customelement/VueCustomElement.js
@@ -0,0 +1,21 @@
+/**
+ * @externs
+ */
+var VueCustomElement = {};
+/**
+ *
+ * @param {Object} param
+ * @return {Element}
+ */
+VueCustomElement.createElement = function(param) {};
+
+/**
+ * @type {Object}
+ */
+Element.prototype.__vue_custom_element__;
+
+/**
+ * @param {Object} param
+ * @return {Function}
+ */
+Function.prototype.extend = function(param) {};
\ No newline at end of file
diff --git a/core/src/main/java/com/axellience/vuegwt/core/client/customelement/VueCustomElementType.java b/core/src/main/java/com/axellience/vuegwt/core/client/customelement/VueCustomElementType.java
index b2f258b4..953986d0 100644
--- a/core/src/main/java/com/axellience/vuegwt/core/client/customelement/VueCustomElementType.java
+++ b/core/src/main/java/com/axellience/vuegwt/core/client/customelement/VueCustomElementType.java
@@ -10,10 +10,13 @@ public class VueCustomElementType<T extends IsVueComponent> {
 
   @JsOverlay
   public final VueCustomElement<T> create() {
-    return createElement(this);
+    return VCE.createElement(this);
   }
 
-  @JsMethod(namespace = "VueCustomElement")
-  private native static <T extends IsVueComponent> VueCustomElement<T> createElement(
-      VueCustomElementType<T> type);
+  @JsType(isNative = true, namespace = "<global>", name = "VueCustomElement")
+  private static final class VCE {
+    @JsMethod
+    private native static <T extends IsVueComponent> VueCustomElement<T> createElement(
+            VueCustomElementType<T> type);
+  }
 }