diff --git a/src/mame/machine/vino.h b/src/mame/machine/vino.h
index d7b5b6ada8f..446664e626f 100644
--- a/src/mame/machine/vino.h
+++ b/src/mame/machine/vino.h
@@ -34,7 +34,7 @@ private:
 		CHAN_COUNT
 	};
 
-	enum
+	enum : u64
 	{
 		CTRL_MASK                   = 0x7fffffff,