diff --git a/mozilla/modules/libpref/src/nsSharedPrefHandler.cpp b/mozilla/modules/libpref/src/nsSharedPrefHandler.cpp
index c5d1d54d233..573aae4cc8f 100644
--- a/mozilla/modules/libpref/src/nsSharedPrefHandler.cpp
+++ b/mozilla/modules/libpref/src/nsSharedPrefHandler.cpp
@@ -271,7 +271,7 @@ nsresult nsSharedPrefHandler::EnsureTransactionService()
   if (mTransService)
     return NS_OK;
   nsresult rv;
-  mTransService = do_GetService("@mozilla.org/transaction/service;1", &rv);
+  mTransService = do_GetService(IPC_TRANSACTIONSERVICE_CONTRACTID, &rv);
   return rv;
 }