diff --git a/t/t1302-repo-version.sh b/t/t1302-repo-version.sh
index 179474fa65..42caa0d297 100755
--- a/t/t1302-repo-version.sh
+++ b/t/t1302-repo-version.sh
@@ -9,10 +9,6 @@ TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'setup' '
-	test_oid_cache <<-\EOF &&
-	version sha1:0
-	version sha256:1
-	EOF
 	cat >test.patch <<-\EOF &&
 	diff --git a/test.txt b/test.txt
 	new file mode 100644
@@ -28,7 +24,12 @@ test_expect_success 'setup' '
 '
 
 test_expect_success 'gitdir selection on normal repos' '
-	test_oid version >expect &&
+	if test_have_prereq DEFAULT_REPO_FORMAT
+	then
+		echo 0
+	else
+		echo 1
+	fi >expect &&
 	git config core.repositoryformatversion >actual &&
 	git -C test config core.repositoryformatversion >actual2 &&
 	test_cmp expect actual &&
@@ -79,8 +80,13 @@ mkconfig () {
 
 while read outcome version extensions; do
 	test_expect_success "$outcome version=$version $extensions" "
-		mkconfig $version $extensions >.git/config &&
-		check_${outcome}
+		test_when_finished 'rm -rf extensions' &&
+		git init extensions &&
+		(
+			cd extensions &&
+			mkconfig $version $extensions >.git/config &&
+			check_${outcome}
+		)
 	"
 done <<\EOF
 allow 0
@@ -94,7 +100,8 @@ allow 1 noop-v1
 EOF
 
 test_expect_success 'precious-objects allowed' '
-	mkconfig 1 preciousObjects >.git/config &&
+	git config core.repositoryFormatVersion 1 &&
+	git config extensions.preciousObjects 1 &&
 	check_allow
 '