diff --git a/source/app/gpr_tools/main_c.c b/source/app/gpr_tools/main_c.c
index 0583b016..b8a331a9 100755
--- a/source/app/gpr_tools/main_c.c
+++ b/source/app/gpr_tools/main_c.c
@@ -17,6 +17,7 @@
  */
 
 #include <stdio.h>
+#include <strings.h>
 #include <string.h>
 #include <stdbool.h>