diff --git a/nl.c b/nl.c
index 434999a..5de4844 100644
--- a/nl.c
+++ b/nl.c
@@ -1,4 +1,5 @@
 /* See LICENSE file for copyright and license details. */
+#include <limits.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>