diff --git a/t/helper/test-dump-cache-tree.c b/t/helper/test-dump-cache-tree.c
index 6a3f88f5f5..0d6d7f1ecb 100644
--- a/t/helper/test-dump-cache-tree.c
+++ b/t/helper/test-dump-cache-tree.c
@@ -59,11 +59,16 @@ int cmd__dump_cache_tree(int ac, const char **av)
 {
 	struct index_state istate;
 	struct cache_tree *another = cache_tree();
+	int ret;
+
 	setup_git_directory();
 	if (read_cache() < 0)
 		die("unable to read index file");
 	istate = the_index;
 	istate.cache_tree = another;
 	cache_tree_update(&istate, WRITE_TREE_DRY_RUN);
-	return dump_cache_tree(active_cache_tree, another, "");
+	ret = dump_cache_tree(active_cache_tree, another, "");
+	cache_tree_free(&another);
+
+	return ret;
 }
diff --git a/t/helper/test-scrap-cache-tree.c b/t/helper/test-scrap-cache-tree.c
index 393f1604ff..026c802479 100644
--- a/t/helper/test-scrap-cache-tree.c
+++ b/t/helper/test-scrap-cache-tree.c
@@ -12,6 +12,7 @@ int cmd__scrap_cache_tree(int ac, const char **av)
 	hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
 	if (read_cache() < 0)
 		die("unable to read index file");
+	cache_tree_free(&active_cache_tree);
 	active_cache_tree = NULL;
 	if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
 		die("unable to write index file");
diff --git a/t/t0090-cache-tree.sh b/t/t0090-cache-tree.sh
index 9067572648..d8e2fc42e1 100755
--- a/t/t0090-cache-tree.sh
+++ b/t/t0090-cache-tree.sh
@@ -5,6 +5,8 @@ test_description="Test whether cache-tree is properly updated
 Tests whether various commands properly update and/or rewrite the
 cache-tree extension.
 "
+
+TEST_PASSES_SANITIZE_LEAK=true
  . ./test-lib.sh
 
 cmp_cache_tree () {