diff --git a/builtin/merge.c b/builtin/merge.c
index 84d0f3604b..51038eaca8 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -754,6 +754,7 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
 			clean = merge_recursive(&o, head, remoteheads->item,
 						reversed, &result);
 		free_commit_list(reversed);
+		strbuf_release(&o.obuf);
 
 		if (clean < 0) {
 			rollback_lock_file(&lock);
diff --git a/t/t6424-merge-unrelated-index-changes.sh b/t/t6424-merge-unrelated-index-changes.sh
index 7677c5f08d..a7ea8acb84 100755
--- a/t/t6424-merge-unrelated-index-changes.sh
+++ b/t/t6424-merge-unrelated-index-changes.sh
@@ -2,6 +2,7 @@
 
 test_description="merges with unrelated index changes"
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # Testcase for some simple merges