diff --git a/drivers/md/bcache/alloc.c b/drivers/md/bcache/alloc.c
index ca4abe1ccd8d..3fba31cea66e 100644
--- a/drivers/md/bcache/alloc.c
+++ b/drivers/md/bcache/alloc.c
@@ -404,7 +404,8 @@ long bch_bucket_alloc(struct cache *ca, unsigned reserve, bool wait)
 
 	finish_wait(&ca->set->bucket_wait, &w);
 out:
-	wake_up_process(ca->alloc_thread);
+	if (ca->alloc_thread)
+		wake_up_process(ca->alloc_thread);
 
 	trace_bcache_alloc(ca, reserve);