diff --git a/sshlogin.c b/sshlogin.c
index 82dd84819..06a7b381a 100644
--- a/sshlogin.c
+++ b/sshlogin.c
@@ -50,6 +50,7 @@
 #include <fcntl.h>
 #include <stdarg.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include <unistd.h>