diff --git a/check/main.c b/check/main.c
index d8181249..37c5b35a 100644
--- a/check/main.c
+++ b/check/main.c
@@ -4516,7 +4516,7 @@ static struct data_backref *alloc_data_backref(struct extent_record *rec,
 
 	if (!ref)
 		return NULL;
-	memset(&ref->node, 0, sizeof(ref->node));
+	memset(ref, 0, sizeof(*ref));
 	ref->node.is_data = 1;
 
 	if (parent > 0) {