diff --git a/compile.c b/compile.c
index 248d363e..f634284f 100644
--- a/compile.c
+++ b/compile.c
@@ -1,4 +1,6 @@
+#ifndef _GNU_SOURCE
 #define _GNU_SOURCE // for strdup
+#endif
 #include <assert.h>
 #include <string.h>
 #include <stdlib.h>