diff --git a/tests/test_map_api.db-shm b/tests/test_map_api.db-shm
deleted file mode 100644
index fe9ac28..0000000
Binary files a/tests/test_map_api.db-shm and /dev/null differ
diff --git a/tests/test_map_api.db-wal b/tests/test_map_api.db-wal
deleted file mode 100644
index e69de29..0000000
diff --git a/tests/test_map_api.py b/tests/test_map_api.py
index fbae1d2..062983d 100644
--- a/tests/test_map_api.py
+++ b/tests/test_map_api.py
@@ -30,13 +30,15 @@ def clean_db():
 
 @pytest.fixture
 def client():
+    # Ensure isolated DB path (module-level env may be overwritten by other tests)
+    os.environ["CANTEEN_DB_PATH"] = str(TEST_DB)
     _clean_db()
+    import importlib
+    importlib.invalidate_caches()
     for mod in list(sys.modules.keys()):
         if mod == "server" or mod.startswith("server."):
             del sys.modules[mod]
     import server
-    import importlib
-    importlib.invalidate_caches()
     with TestClient(server.app) as tc:
         yield tc