diff --git a/libCacheSim/bin/cachesim/cache_init.h b/libCacheSim/bin/cachesim/cache_init.h
index dad4424a..1f366c1c 100644
--- a/libCacheSim/bin/cachesim/cache_init.h
+++ b/libCacheSim/bin/cachesim/cache_init.h
@@ -1,11 +1,8 @@
 
-#include <strings.h>
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <strings.h>
 
 #include "libCacheSim/cache.h"
 #include "libCacheSim/evictionAlgo.h"
diff --git a/libCacheSim/bin/cachesim/main.c b/libCacheSim/bin/cachesim/main.c
index 636403df..b95f0d55 100644
--- a/libCacheSim/bin/cachesim/main.c
+++ b/libCacheSim/bin/cachesim/main.c
@@ -1,4 +1,4 @@
-
+#define _GNU_SOURCE
 
 #ifdef __linux__
 #include <sys/sysinfo.h>
diff --git a/libCacheSim/bin/cachesim/sim.c b/libCacheSim/bin/cachesim/sim.c
index 3a96cd4e..a85a25b3 100644
--- a/libCacheSim/bin/cachesim/sim.c
+++ b/libCacheSim/bin/cachesim/sim.c
@@ -1,3 +1,5 @@
+#define _GNU_SOURCE
+
 #include "cache_init.h"
 #include "libCacheSim/cache.h"
 #include "libCacheSim/reader.h"