diff --git a/Lib/lua/lua.swg b/Lib/lua/lua.swg
index dd95ce80a..59687cc5a 100644
--- a/Lib/lua/lua.swg
+++ b/Lib/lua/lua.swg
@@ -181,6 +181,7 @@ For a more useful solution: see std_except for more details
 */
 %typemap(throws) SWIGTYPE
 {
+  (void)$1;
   lua_pushfstring(L,"object exception:%s",SWIG_TypePrettyName($1_descriptor));
   SWIG_fail;
 }