diff --git a/src/hlua_fcn.c b/src/hlua_fcn.c
index ed094b7..06ff48d 100644
--- a/src/hlua_fcn.c
+++ b/src/hlua_fcn.c
@@ -14,6 +14,9 @@
  * in an environment able to catch a longjmp, otherwise a
  * critical error can be raised.
  */
+
+#define _GNU_SOURCE
+
 #include <lauxlib.h>
 #include <lua.h>
 #include <lualib.h>