diff --git a/server/core/maxkeys.c b/server/core/maxkeys.c
index ad1e28f86..747e575ec 100644
--- a/server/core/maxkeys.c
+++ b/server/core/maxkeys.c
@@ -30,7 +30,7 @@
 #include	<stdio.h>
 #include	<secrets.h>
 
-main(int argc, char **argv)
+int main(int argc, char **argv)
 {
 	if (argc != 2)
 	{