diff --git a/tests/test_coordinator.py b/tests/test_coordinator.py
index 1902966..c52e6db 100644
--- a/tests/test_coordinator.py
+++ b/tests/test_coordinator.py
@@ -12,7 +12,13 @@ def test_load_test_credentials(tmp_path: Path):
     DIR.create_all_dirs()
 
     Coordinator.load_test_credentials(DIR)
+    assert (DIR.STATES / "credentials_test.json").is_file()
 
     assert "TEST_USER" in os.environ
+    test_user_before = os.environ["TEST_USER"]
 
-    assert (DIR.STATES / "credentials_test.json").is_file()
+    os.environ.clear()
+    assert "TEST_USER" not in os.environ
+
+    Coordinator.load_test_credentials(DIR)
+    assert test_user_before == os.environ["TEST_USER"]