diff --git a/dom/base/nsJSEnvironment.cpp b/dom/base/nsJSEnvironment.cpp
index 2134bd4c60e..cc28f2ff731 100644
--- a/dom/base/nsJSEnvironment.cpp
+++ b/dom/base/nsJSEnvironment.cpp
@@ -509,7 +509,7 @@ NS_ScriptErrorReporter(JSContext *cx,
       const PRUnichar* m = static_cast<const PRUnichar*>(report->ucmessage);
       if (m) {
         const PRUnichar* n = static_cast<const PRUnichar*>
-            (js::GetErrorTypeName(cx, report->exnType));
+          (js::GetErrorTypeName(JS_GetRuntime(cx), report->exnType));
         if (n) {
           msg.Assign(n);
           msg.AppendLiteral(": ");
diff --git a/js/src/jsatominlines.h b/js/src/jsatominlines.h
index bf5c59de7cd..71d80fdaac4 100644
--- a/js/src/jsatominlines.h
+++ b/js/src/jsatominlines.h
@@ -193,14 +193,26 @@ TypeName(JSType type, JSContext *cx)
 }
 
 inline Handle<PropertyName*>
-ClassName(JSProtoKey key, ExclusiveContext *cx)
+ClassName(JSProtoKey key, JSAtomState &atomState)
 {
     JS_ASSERT(key < JSProto_LIMIT);
     JS_STATIC_ASSERT(offsetof(JSAtomState, Null) +
                      JSProto_LIMIT * sizeof(FixedHeapPtr<PropertyName>) <=
                      sizeof(JSAtomState));
     JS_STATIC_ASSERT(JSProto_Null == 0);
-    return (&cx->names().Null)[key];
+    return (&atomState.Null)[key];
+}
+
+inline Handle<PropertyName*>
+ClassName(JSProtoKey key, JSRuntime *rt)
+{
+    return ClassName(key, rt->atomState);
+}
+
+inline Handle<PropertyName*>
+ClassName(JSProtoKey key, ExclusiveContext *cx)
+{
+    return ClassName(key, cx->names());
 }
 
 } // namespace js
diff --git a/js/src/jsexn.cpp b/js/src/jsexn.cpp
index 56286ae8880..df69ec03c35 100644
--- a/js/src/jsexn.cpp
+++ b/js/src/jsexn.cpp
@@ -872,7 +872,7 @@ js_GetLocalizedErrorMessage(JSContext* cx, void *userRef, const char *locale,
 }
 
 JS_FRIEND_API(const jschar*)
-js::GetErrorTypeName(JSContext* cx, int16_t exnType)
+js::GetErrorTypeName(JSRuntime* rt, int16_t exnType)
 {
     /*
      * JSEXN_INTERNALERR returns null to prevent that "InternalError: "
@@ -884,7 +884,7 @@ js::GetErrorTypeName(JSContext* cx, int16_t exnType)
         return NULL;
     }
     JSProtoKey key = GetExceptionProtoKey(exnType);
-    return ClassName(key, cx)->chars();
+    return ClassName(key, rt)->chars();
 }
 
 #if defined ( DEBUG_mccabe ) && defined ( PRINTNAMES )
diff --git a/js/src/jsfriendapi.h b/js/src/jsfriendapi.h
index 6aef6aa0a62..c81e6019a2c 100644
--- a/js/src/jsfriendapi.h
+++ b/js/src/jsfriendapi.h
@@ -713,7 +713,7 @@ CastToJSFreeOp(FreeOp *fop)
  * Returns NULL for invalid arguments and JSEXN_INTERNALERR
  */
 extern JS_FRIEND_API(const jschar*)
-GetErrorTypeName(JSContext* cx, int16_t exnType);
+GetErrorTypeName(JSRuntime* rt, int16_t exnType);
 
 #ifdef DEBUG
 extern JS_FRIEND_API(unsigned)