diff --git a/src/hlua.c b/src/hlua.c
index 785a1fa36..0de1937db 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -10,6 +10,8 @@
  *
  */
 
+#define _GNU_SOURCE
+
 #include <ctype.h>
 #include <setjmp.h>
 
diff --git a/src/hlua_fcn.c b/src/hlua_fcn.c
index 1f66c181f..aab864370 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>