diff --git a/super0.c b/super0.c
index d53f025..eca40d2 100644
--- a/super0.c
+++ b/super0.c
@@ -942,10 +942,10 @@ static int load_super0(struct supertype *st, int fd, char *devname)
 
 static struct supertype *match_metadata_desc0(char *arg)
 {
-	struct supertype *st = malloc(sizeof(*st));
-	if (!st) return st;
+	struct supertype *st = calloc(1, sizeof(*st));
+	if (!st)
+		return st;
 
-	memset(st, 0, sizeof(*st));
 	st->container_dev = NoMdDev;
 	st->ss = &super0;
 	st->info = NULL;