--- a/dom/ipc/ContentParent.cpp
+++ b/dom/ipc/ContentParent.cpp
@@ -4439,16 +4439,19 @@ ContentParent::RecvRemoveFakeVolume(cons
 }
 
 bool
 ContentParent::RecvKeywordToURI(const nsCString& aKeyword,
                                 nsString* aProviderName,
                                 OptionalInputStreamParams* aPostData,
                                 OptionalURIParams* aURI)
 {
+  *aPostData = void_t();
+  *aURI = void_t();
+
   nsCOMPtr<nsIURIFixup> fixup = do_GetService(NS_URIFIXUP_CONTRACTID);
   if (!fixup) {
     return true;
   }
 
   nsCOMPtr<nsIInputStream> postData;
   nsCOMPtr<nsIURIFixupInfo> info;