1 files changed, 3 insertions, 1 deletions
diff --git a/proc.c b/proc.c
index b0c577c..76e3c93 100644
--- a/proc.c
+++ b/proc.c
@@ -1,4 +1,6 @@
-#define _GNU_SOURCE
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE
+#endif
 #include <sched.h>
 #include <sys/wait.h>
 #include <sys/types.h>