diff --git a/t/t3430-rebase-merges.sh b/t/t3430-rebase-merges.sh
index 36ca126bcd..2aa8593f77 100755
--- a/t/t3430-rebase-merges.sh
+++ b/t/t3430-rebase-merges.sh
@@ -392,8 +392,7 @@ test_expect_success 'refuse to merge ancestors of HEAD' '
 
 test_expect_success 'root commits' '
 	git checkout --orphan unrelated &&
-	(GIT_AUTHOR_NAME="Parsnip" GIT_AUTHOR_EMAIL="root@example.com" \
-	 test_commit second-root) &&
+	test_commit --author "Parsnip <root@example.com>" second-root &&
 	test_commit third-root &&
 	cat >script-from-scratch <<-\EOF &&
 	pick third-root