diff --git a/tests/test_client.py b/tests/test_client.py
index a94c62f..ec228a5 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -29,9 +29,11 @@ GIT_ENV = {
 }
 
 
-def run_git(cwd, *args):
-    return subprocess.run(["git", "-C", cwd] + list(args), check=True,
-                          capture_output=True, text=True, env=GIT_ENV).stdout.strip()
+def run_git(cwd, *args, strip=True):
+    stdout = subprocess.run(["git", "-C", cwd] + list(args), check=True,
+                            capture_output=True, text=True,
+                            env=GIT_ENV).stdout
+    return stdout.strip() if strip else stdout
 
 
 
@@ -905,15 +907,13 @@ class TestCredentialHelperIsolation(GitScenarioBase):
     def test_install_leaves_exactly_one_helper(self):
         run_git(self.local, "config", "--add", "credential.helper", "store")
         client.install_credential_helper(self.local)
-        # --get-all merges system + global + local, so entries inherited from
-        # the machine still appear. What matters is that the last two are the
-        # reset and ours: git reads an empty value as "forget every helper
-        # inherited so far", so nothing before it can answer.
-        helpers = run_git(self.local, "config", "--get-all",
-                          "credential.helper").splitlines()
-        self.assertEqual(helpers[-2], "", helpers)
-        self.assertIn("git-credential", helpers[-1])
-        # the repo-level 'store' this test added is gone, not merely outvoted
+        # Inspect the repo-local list so this assertion is deterministic even
+        # when the machine has no inherited helper. Keep the leading newline:
+        # it represents the empty reset value, not disposable whitespace.
+        helpers = run_git(self.local, "config", "--local", "--get-all",
+                          "credential.helper", strip=False).splitlines()
+        self.assertEqual(helpers, ["", client.credential_helper_value()])
+        # The repo-level 'store' this test added is gone, not merely outvoted.
         self.assertNotIn("store", helpers)
 
     def test_inherited_helper_cannot_answer_for_the_forge(self):