diff --git a/nanoidgen.c b/nanoidgen.c
index 193dfa4..5328d80 100644
--- a/nanoidgen.c
+++ b/nanoidgen.c
@@ -1,5 +1,6 @@
 #include "nanoid.h"
 #include <errno.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>