diff --git a/tools/country_select.C b/tools/country_select.C
index e49f8a2e38..1b73c25fc6 100644
--- a/tools/country_select.C
+++ b/tools/country_select.C
@@ -18,6 +18,7 @@
 //
 
 #include <stdio.h>
+#include <string.h>
 
 #include "countries.h"