diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index c8a9ca1eeae7..7c3725e4ac54 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1292,6 +1292,20 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		goto bad_store;
 	}
 
+	/*
+	 * snapshot-merge requires the optional prepare_merge/commit_merge
+	 * callbacks; the transient exception store does not implement them.
+	 * The handover path checks this in __validate_exception_handover(),
+	 * but a directly constructed snapshot-merge never goes through it.
+	 */
+	if (dm_target_is_snapshot_merge(ti) &&
+	    (!s->store->type->prepare_merge ||
+	     !s->store->type->commit_merge)) {
+		ti->error = "Snapshot exception store does not support snapshot-merge.";
+		r = -EINVAL;
+		goto bad_hash_tables;
+	}
+
 	argv += args_used;
 	argc -= args_used;