diff --git a/t/t4027-diff-submodule.sh b/t/t4027-diff-submodule.sh
index 6cef0da982..295da987cc 100755
--- a/t/t4027-diff-submodule.sh
+++ b/t/t4027-diff-submodule.sh
@@ -2,7 +2,6 @@
 
 test_description='difference in submodules'
 
-TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-diff.sh
 
@@ -28,10 +27,8 @@ test_expect_success setup '
 		git commit -m "submodule #2"
 	) &&
 
-	set x $(
-		cd sub &&
-		git rev-list HEAD
-	) &&
+	git -C sub rev-list HEAD >revs &&
+	set x $(cat revs) &&
 	echo ":160000 160000 $3 $ZERO_OID M	sub" >expect &&
 	subtip=$3 subprev=$2
 '