diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 31f8ca046639..10ec27676191 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -700,9 +700,11 @@ void jbd2_journal_commit_transaction(journal_t *journal)
                            the last tag we set up. */
 
 			tag->t_flags |= cpu_to_be16(JBD2_FLAG_LAST_TAG);
-
-			jbd2_descriptor_block_csum_set(journal, descriptor);
 start_journal_io:
+			if (descriptor)
+				jbd2_descriptor_block_csum_set(journal,
+							descriptor);
+
 			for (i = 0; i < bufs; i++) {
 				struct buffer_head *bh = wbuf[i];
 				/*