diff --git a/openbsd-compat/port-linux.c b/openbsd-compat/port-linux.c
index 8c5325cc3..622988822 100644
--- a/openbsd-compat/port-linux.c
+++ b/openbsd-compat/port-linux.c
@@ -26,6 +26,7 @@
 #include <stdarg.h>
 #include <string.h>
 #include <stdio.h>
+#include <stdlib.h>
 
 #include "log.h"
 #include "xmalloc.h"