diff --git a/content/xul/document/src/nsXULPrototypeCache.cpp b/content/xul/document/src/nsXULPrototypeCache.cpp
index b499113b2a2..7fbb6ec09ae 100644
--- a/content/xul/document/src/nsXULPrototypeCache.cpp
+++ b/content/xul/document/src/nsXULPrototypeCache.cpp
@@ -235,7 +235,7 @@ nsXULPrototypeCache::GetScript(nsIURI* aURI, PRUint32 *aLangID)
         return nsnull;
     }
     *aLangID = entry.mScriptTypeID;
-    return static_cast<JSScript*>(entry.mScriptObject);
+    return entry.mScriptObject;
 }
 
 
@@ -250,7 +250,7 @@ ReleaseScriptObjectCallback(nsIURI* aKey, CacheScriptEntry &aData, void* aClosur
 }
 
 nsresult
-nsXULPrototypeCache::PutScript(nsIURI* aURI, PRUint32 aLangID, void* aScriptObject)
+nsXULPrototypeCache::PutScript(nsIURI* aURI, PRUint32 aLangID, JSScript* aScriptObject)
 {
     CacheScriptEntry existingEntry;
     if (mScriptTable.Get(aURI, &existingEntry)) {
diff --git a/content/xul/document/src/nsXULPrototypeCache.h b/content/xul/document/src/nsXULPrototypeCache.h
index f10bce9e980..5f39e32d05a 100644
--- a/content/xul/document/src/nsXULPrototypeCache.h
+++ b/content/xul/document/src/nsXULPrototypeCache.h
@@ -53,6 +53,9 @@
 #include "nsXULPrototypeDocument.h"
 #include "nsIInputStream.h"
 #include "nsIStorageStream.h"
+
+#include "jspubtd.h"
+
 #include "mozilla/scache/StartupCache.h"
 
 using namespace mozilla::scache;
@@ -62,7 +65,7 @@ class nsCSSStyleSheet;
 struct CacheScriptEntry
 {
     PRUint32    mScriptTypeID; // the script language ID.
-    void*       mScriptObject; // the script object.
+    JSScript*   mScriptObject; // the script object.
 };
 
 /**
@@ -105,7 +108,7 @@ public:
     nsresult PutPrototype(nsXULPrototypeDocument* aDocument);
 
     JSScript* GetScript(nsIURI* aURI, PRUint32* langID);
-    nsresult PutScript(nsIURI* aURI, PRUint32 langID, void* aScriptObject);
+    nsresult PutScript(nsIURI* aURI, PRUint32 langID, JSScript* aScriptObject);
 
     nsXBLDocumentInfo* GetXBLDocumentInfo(nsIURI* aURL) {
         return mXBLDocTable.GetWeak(aURL);