diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index add7d4ce4180..e902aae685af 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -854,7 +854,7 @@ static int dm_add_exception(void *context, chunk_t old, chunk_t new)
 static uint32_t __minimum_chunk_size(struct origin *o)
 {
 	struct dm_snapshot *snap;
-	unsigned chunk_size = 0;
+	unsigned chunk_size = rounddown_pow_of_two(UINT_MAX);
 
 	if (o)
 		list_for_each_entry(snap, &o->snapshots, list)