diff --git a/disk/part.c b/disk/part.c
index 72241b7b232..91275154001 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -337,7 +337,7 @@ static void print_part_header(const char *type, struct blk_desc *desc)
 		puts("EFI");
 		break;
 	default:
-		puts("UNKNOWN");
+		printf("UNKNOWN(%d)", desc->uclass_id);
 		break;
 	}
 	printf (" device %d  --   Partition Type: %s\n\n",