diff --git a/sys/dev/asmc/asmc.c b/sys/dev/asmc/asmc.c
index ae4d7b8aeee9..f99c79c39ad8 100644
--- a/sys/dev/asmc/asmc.c
+++ b/sys/dev/asmc/asmc.c
@@ -824,7 +824,7 @@ asmc_key_dump(device_t dev, int number)
 		type[5] = 0;
 		if (maxlen > sizeof(v)) {	
 			device_printf(dev, "WARNING: cropping maxlen "
-			    "from %u to %u\n", maxlen, sizeof(v));
+			    "from %u to %lu\n", maxlen, sizeof(v));
 			maxlen = sizeof(v);
 		}
 		for (i = 0; i < sizeof(v); i++) {