diff --git a/dom/base/nsIScriptContext.h b/dom/base/nsIScriptContext.h
index f6a4b28a4f50..1cdb72f0950c 100644
--- a/dom/base/nsIScriptContext.h
+++ b/dom/base/nsIScriptContext.h
@@ -74,8 +74,8 @@ NS_DEFINE_STATIC_IID_ACCESSOR(nsIScriptContextPrincipal,
                               NS_ISCRIPTCONTEXTPRINCIPAL_IID)
 
 #define NS_ISCRIPTCONTEXT_IID \
-{ 0x8bfc08bb, 0x0127, 0x46d5, \
-  { 0x95, 0xfc, 0xca, 0x25, 0xa0, 0x62, 0xc9, 0x9a } }
+{ 0xddc9b75f, 0xa230, 0x4966, \
+  { 0xa6, 0xe0, 0x67, 0x5a, 0xba, 0xc9, 0x08, 0x8c } }
 
 /* This MUST match JSVERSION_DEFAULT.  This version stuff if we don't
    know what language we have is a little silly... */
@@ -172,7 +172,7 @@ public:
    * @return NS_OK if the script was valid and got executed
    *
    */
-  virtual nsresult ExecuteScript(void* aScriptObject,
+  virtual nsresult ExecuteScript(JSScript* aScriptObject,
                                  JSObject* aScopeObject,
                                  nsAString* aRetValue,
                                  bool* aIsUndefined) = 0;
diff --git a/dom/base/nsJSEnvironment.cpp b/dom/base/nsJSEnvironment.cpp
index 569dbeff4bd9..dfa4cdfbad15 100644
--- a/dom/base/nsJSEnvironment.cpp
+++ b/dom/base/nsJSEnvironment.cpp
@@ -1596,7 +1596,7 @@ nsJSContext::CompileScript(const PRUnichar* aText,
 }
 
 nsresult
-nsJSContext::ExecuteScript(void *aScriptObject,
+nsJSContext::ExecuteScript(JSScript* aScriptObject,
                            JSObject* aScopeObject,
                            nsAString* aRetValue,
                            bool* aIsUndefined)
@@ -1628,10 +1628,9 @@ nsJSContext::ExecuteScript(void *aScriptObject,
     return NS_ERROR_FAILURE;
   }
 
-  JSScript *script = static_cast<JSScript *>(aScriptObject);
   nsCOMPtr<nsIPrincipal> principal;
   rv = sSecurityManager->GetObjectPrincipal(mContext,
-                                            JS_GetGlobalFromScript(script),
+                                            JS_GetGlobalFromScript(aScriptObject),
                                             getter_AddRefs(principal));
   NS_ENSURE_SUCCESS(rv, rv);
 
@@ -1646,7 +1645,7 @@ nsJSContext::ExecuteScript(void *aScriptObject,
   // not be a GC root currently, provided we run the GC only from the
   // operation callback or from ScriptEvaluated.
   jsval val;
-  bool ok = JS_ExecuteScript(mContext, aScopeObject, script, &val);
+  bool ok = JS_ExecuteScript(mContext, aScopeObject, aScriptObject, &val);
   if (ok) {
     // If all went well, convert val to a string (XXXbe unless undefined?).
     rv = JSValueToAString(mContext, val, aRetValue, aIsUndefined);
diff --git a/dom/base/nsJSEnvironment.h b/dom/base/nsJSEnvironment.h
index c37d1ec6d2f6..7066773e743b 100644
--- a/dom/base/nsJSEnvironment.h
+++ b/dom/base/nsJSEnvironment.h
@@ -97,7 +97,7 @@ public:
                                  PRUint32 aLineNo,
                                  PRUint32 aVersion,
                                  nsScriptObjectHolder &aScriptObject);
-  virtual nsresult ExecuteScript(void* aScriptObject,
+  virtual nsresult ExecuteScript(JSScript* aScriptObject,
                                  JSObject* aScopeObject,
                                  nsAString* aRetValue,
                                  bool* aIsUndefined);