diff --git a/compiler/java/com/google/dart/compiler/backend/js/GenerateJavascriptAST.java b/compiler/java/com/google/dart/compiler/backend/js/GenerateJavascriptAST.java
index 1829e5946c0..fd31b2fc2b2 100644
--- a/compiler/java/com/google/dart/compiler/backend/js/GenerateJavascriptAST.java
+++ b/compiler/java/com/google/dart/compiler/backend/js/GenerateJavascriptAST.java
@@ -2687,11 +2687,13 @@ public class GenerateJavascriptAST {
       if (typeParams != null && typeParams.size() != 0) {
         JsArrayLiteral arr = new JsArrayLiteral();
         for (Type t : typeParams) {
-          String typeName = "";
+          JsExpression typeName;
           if (t.getKind() != TypeKind.DYNAMIC) {
-            typeName = getJsName(t.getElement()).getShortIdent();
+            typeName = rtt.getRTTClassId((ClassElement)t.getElement());
+          } else {
+            typeName = string("");
           }
-          arr.getExpressions().add(string(typeName));
+          arr.getExpressions().add(typeName);
         }
         intern.getArguments().add(arr);
       }
diff --git a/compiler/java/com/google/dart/compiler/backend/js/RuntimeTypeInjector.java b/compiler/java/com/google/dart/compiler/backend/js/RuntimeTypeInjector.java
index 4399656ac06..30103693d3a 100644
--- a/compiler/java/com/google/dart/compiler/backend/js/RuntimeTypeInjector.java
+++ b/compiler/java/com/google/dart/compiler/backend/js/RuntimeTypeInjector.java
@@ -50,6 +50,7 @@ import com.google.dart.compiler.backend.js.ast.JsProgram;
 import com.google.dart.compiler.backend.js.ast.JsReturn;
 import com.google.dart.compiler.backend.js.ast.JsScope;
 import com.google.dart.compiler.backend.js.ast.JsStatement;
+import com.google.dart.compiler.backend.js.ast.JsStringLiteral;
 import com.google.dart.compiler.backend.js.ast.JsThisRef;
 import com.google.dart.compiler.common.SourceInfo;
 import com.google.dart.compiler.resolver.ClassElement;
@@ -357,10 +358,16 @@ public class RuntimeTypeInjector {
     globalBlock.getStatements().add(fnDecl.makeStmt());
   }
 
-  private JsExpression getRTTClassId(ClassElement classElement) {
+  static JsExpression getRTTClassId(TranslationContext translationContext,
+                                    ClassElement classElement) {
     JsName classJsName = translationContext.getNames().getName(classElement);
     JsProgram program = translationContext.getProgram();
-    return program.getStringLiteral(classJsName.getShortIdent());
+    JsStringLiteral clsid = program.getStringLiteral(classJsName.getShortIdent());
+    return call(null, nameref(null, "$cls"), clsid);
+  }
+
+  JsExpression getRTTClassId(ClassElement classElement) {
+    return getRTTClassId(translationContext, classElement);
   }
 
   private JsNameRef getRTTLookupMethodName(ClassElement classElement) {
diff --git a/compiler/lib/implementation/rtt.js b/compiler/lib/implementation/rtt.js
index 68ecb5b3f8d..8bd156bd64f 100644
--- a/compiler/lib/implementation/rtt.js
+++ b/compiler/lib/implementation/rtt.js
@@ -19,8 +19,8 @@ function RTT(classkey, typekey, typeargs) {
   // Add self
   this.implementedTypes[classkey] = this;
   // Add Object
-  if (classkey != 'Object') {
-    this.implementedTypes['Object'] = RTT.objectType;
+  if (classkey != $cls('Object')) {
+    this.implementedTypes[$cls('Object')] = RTT.objectType;
   }
 }
 
@@ -93,7 +93,7 @@ RTT.getNativeTypeInfo = function(value) {
  * @return {RTT} The RTT information object
  */
 RTT.create = function(name, implementsSupplier, typeArgs) {
-  if (name == "Object") return RTT.objectType;
+  if (name == $cls("Object")) return RTT.objectType;
   var typekey = RTT.getTypeKey(name, typeArgs);
   var rtt = RTT.types[typekey];
   if (rtt) {
@@ -183,18 +183,25 @@ RTT.getTypeArgsFor = function(o, classkey) {
 // Base types for runtime type information
 
 /** @type {!RTT} */
-RTT.objectType = new RTT('Object');
+RTT.objectType = new RTT($cls('Object'));
 RTT.objectType.implementedBy = function(o) {return true};
 RTT.objectType.implementedByType = function(o) {return true};
 
 /** @type {!RTT} */
-RTT.dynamicType = new RTT('Dynamic');
+RTT.dynamicType = new RTT($cls('Dynamic'));
 RTT.dynamicType.implementedBy = function(o) {return true};
 RTT.dynamicType.implementedByType = function(o) {return true};
 
 /** @type {!RTT} */
-RTT.placeholderType = new RTT('');
+RTT.placeholderType = new RTT($cls('::'));
 RTT.placeholderType.implementedBy = function(o) {return true};
 RTT.placeholderType.implementedByType = function(o) {return true};
 
-
+/** 
+ * @param {string} cls 
+ * @return {string}
+ * @consistentIdGenerator 
+ */
+function $cls(cls) {
+  return "cls:" + cls;
+}