diff --git a/main.c b/main.c
index 371b3b6..7a6c6c8 100644
--- a/main.c
+++ b/main.c
@@ -1074,7 +1074,7 @@ static bool do_move(void)
     return true;
 }
 
-static bool do_command()
+static bool do_command(void)
 /* Get and execute a command */
 {
     static command_t command;