diff --git a/mozilla/xpcom/components/nsICategoryManager.idl b/mozilla/xpcom/components/nsICategoryManager.idl
index f082ae2c543..8c0e093e02c 100644
--- a/mozilla/xpcom/components/nsICategoryManager.idl
+++ b/mozilla/xpcom/components/nsICategoryManager.idl
@@ -118,5 +118,5 @@ interface nsICategoryManager : nsISupports
 { 0x16d222a6, 0x1dd2, 0x11b2, \
   {0xb6, 0x93, 0xf3, 0x8b, 0x02, 0xc0, 0x21, 0xb2} }
 
-extern "C" NS_EXPORT NS_CategoryManagerGetFactory( nsIFactory** );
+extern "C" NS_EXPORT nsresult NS_CategoryManagerGetFactory( nsIFactory** );
 %}