diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index d88994f71eae..a0165c6e6243 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3416,6 +3416,7 @@ int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
 struct btrfs_block_group_cache *btrfs_lookup_block_group(
 						 struct btrfs_fs_info *info,
 						 u64 bytenr);
+void btrfs_get_block_group(struct btrfs_block_group_cache *cache);
 void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 int get_block_group_index(struct btrfs_block_group_cache *cache);
 struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index e97d6d61cd42..8fd14b6f1d33 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -124,7 +124,7 @@ static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
 	return (cache->flags & bits) == bits;
 }
 
-static void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
+void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
 {
 	atomic_inc(&cache->count);
 }
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 68af3169d527..b091d94ceef6 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3641,6 +3641,28 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 		if (ro_set)
 			btrfs_dec_block_group_ro(root, cache);
 
+		/*
+		 * We might have prevented the cleaner kthread from deleting
+		 * this block group if it was already unused because we raced
+		 * and set it to RO mode first. So add it back to the unused
+		 * list, otherwise it might not ever be deleted unless a manual
+		 * balance is triggered or it becomes used and unused again.
+		 */
+		spin_lock(&cache->lock);
+		if (!cache->removed && !cache->ro && cache->reserved == 0 &&
+		    btrfs_block_group_used(&cache->item) == 0) {
+			spin_unlock(&cache->lock);
+			spin_lock(&fs_info->unused_bgs_lock);
+			if (list_empty(&cache->bg_list)) {
+				btrfs_get_block_group(cache);
+				list_add_tail(&cache->bg_list,
+					      &fs_info->unused_bgs);
+			}
+			spin_unlock(&fs_info->unused_bgs_lock);
+		} else {
+			spin_unlock(&cache->lock);
+		}
+
 		btrfs_put_block_group(cache);
 		if (ret)
 			break;