diff --git a/xpcom/reflect/xptcall/src/md/unix/xptcstubs_x86_64_linux.cpp b/xpcom/reflect/xptcall/src/md/unix/xptcstubs_x86_64_linux.cpp
index 495bb4bfe66b..39b6cf9629d8 100644
--- a/xpcom/reflect/xptcall/src/md/unix/xptcstubs_x86_64_linux.cpp
+++ b/xpcom/reflect/xptcall/src/md/unix/xptcstubs_x86_64_linux.cpp
@@ -62,7 +62,7 @@ const PRUint32 FPR_COUNT            = 8;
 // The parameters are mapped into an array of type 'nsXPTCMiniVariant'
 // and then the method gets called.
 
-extern "C" nsresult
+extern "C" nsresult ATTRIBUTE_USED
 PrepareAndDispatch(nsXPTCStubBase * self, PRUint32 methodIndex,
                    PRUint64 * args, PRUint64 * gpregs, double *fpregs)
 {