diff --git a/t/perf/p0001-rev-list.sh b/t/perf/p0001-rev-list.sh
index 16359d51ae..ebf172401b 100755
--- a/t/perf/p0001-rev-list.sh
+++ b/t/perf/p0001-rev-list.sh
@@ -15,7 +15,8 @@ test_perf 'rev-list --all --objects' '
 '
 
 test_expect_success 'create new unreferenced commit' '
-	commit=$(git commit-tree HEAD^{tree} -p HEAD)
+	commit=$(git commit-tree HEAD^{tree} -p HEAD) &&
+	test_export commit
 '
 
 test_perf 'rev-list $commit --not --all' '
diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index 46f08ee087..ab4b8b06ae 100644
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -83,7 +83,7 @@ test_perf_create_repo_from () {
 	error "bug in the test script: not 2 parameters to test-create-repo"
 	repo="$1"
 	source="$2"
-	source_git="$(git -C "$source" rev-parse --git-dir)"
+	source_git="$("$MODERN_GIT" -C "$source" rev-parse --git-dir)"
 	objects_dir="$("$MODERN_GIT" -C "$source" rev-parse --git-path objects)"
 	mkdir -p "$repo/.git"
 	(
@@ -102,7 +102,7 @@ test_perf_create_repo_from () {
 	) &&
 	(
 		cd "$repo" &&
-		git init -q && {
+		"$MODERN_GIT" init -q && {
 			test_have_prereq SYMLINKS ||
 			git config core.symlinks false
 		} &&
diff --git a/t/perf/run b/t/perf/run
index e8adedadfd..c788d713ae 100755
--- a/t/perf/run
+++ b/t/perf/run
@@ -63,6 +63,9 @@ run_dirs_helper () {
 		unset GIT_TEST_INSTALLED
 	else
 		GIT_TEST_INSTALLED="$mydir/bin-wrappers"
+		# Older versions of git lacked bin-wrappers; fallback to the
+		# files in the root.
+		test -d "$GIT_TEST_INSTALLED" || GIT_TEST_INSTALLED=$mydir
 		export GIT_TEST_INSTALLED
 	fi
 	run_one_dir "$@"