diff --git a/backend/app/api/controllers/search_controller.py b/backend/app/api/controllers/search_controller.py
index 8f5f3b50dd..2ecfd85c95 100644
--- a/backend/app/api/controllers/search_controller.py
+++ b/backend/app/api/controllers/search_controller.py
@@ -18,7 +18,7 @@ def __init__(self) -> None:
 
     def _serialize_datetime(self, obj: Any) -> Any:
         """Recursively serialize datetime objects to ISO format strings"""
-        if isinstance(obj, (str, int, float, bool, type(None))):
+        if isinstance(obj, str | int | float | bool) or obj is None:
             return obj
         elif hasattr(obj, "isoformat"):  # datetime objects
             return obj.isoformat()
diff --git a/backend/app/services/dropbox_service.py b/backend/app/services/dropbox_service.py
index 33eda176b2..569bbf874c 100644
--- a/backend/app/services/dropbox_service.py
+++ b/backend/app/services/dropbox_service.py
@@ -742,6 +742,10 @@ def process_matches(matches):
                         dbx_ns.files_search_v2, search_arg
                     )
 
+                    # Capture loop variables to avoid B023 error
+                    namespace_id = ns.namespace_id
+                    namespace_name = ns.name
+
                     def process_ns_matches(matches):
                         for match in matches:
                             if hasattr(match, "metadata") and hasattr(
@@ -757,8 +761,8 @@ def process_ns_matches(matches):
                                     "path_display": entry.path_display,
                                     ".tag": "file" if is_file else "folder",
                                     "namespace_type": "team",
-                                    "namespace_id": ns.namespace_id,
-                                    "namespace_name": ns.name,
+                                    "namespace_id": namespace_id,
+                                    "namespace_name": namespace_name,
                                 }
 
                                 if is_file:
diff --git a/backend/tests/api/routes/test_dropbox.py b/backend/tests/api/routes/test_dropbox.py
index 5e4a593b7e..9ce9464482 100644
--- a/backend/tests/api/routes/test_dropbox.py
+++ b/backend/tests/api/routes/test_dropbox.py
@@ -19,7 +19,7 @@
 def test_user(db: Session) -> User:
     """Create a test user."""
     user = User(
-        email="dropbox_test@example.com",
+        email=f"dropbox_test_{uuid.uuid4()}@example.com",
         hashed_password="hashed",
         first_name="Test",
         last_name="User",
diff --git a/backend/tests/api/routes/test_one_drive.py b/backend/tests/api/routes/test_one_drive.py
index 02624807f7..bf3766d890 100644
--- a/backend/tests/api/routes/test_one_drive.py
+++ b/backend/tests/api/routes/test_one_drive.py
@@ -19,7 +19,7 @@
 def test_user(db: Session) -> User:
     """Create a test user."""
     user = User(
-        email="onedrive_test@example.com",
+        email=f"onedrive_test_{uuid.uuid4()}@example.com",
         hashed_password="hashed",
         first_name="Test",
         last_name="User",
diff --git a/backend/tests/unit/test_external_account.py b/backend/tests/unit/test_external_account.py
index 6ac9eea1cd..31fafce5cd 100644
--- a/backend/tests/unit/test_external_account.py
+++ b/backend/tests/unit/test_external_account.py
@@ -14,7 +14,7 @@ def test_external_account_model_creation(db: Session):
     """Test ExternalAccount model creation to ensure TYPE_CHECKING import is exercised."""
     # Create a user first
     user = User(
-        email="test@example.com",
+        email=f"test_external_account_{uuid.uuid4()}@example.com",
         hashed_password="hashed",
         first_name="Test",
         last_name="User",
diff --git a/backend/tests/unit/test_one_drive_service.py b/backend/tests/unit/test_one_drive_service.py
index 2a7a015ab5..b0c32f30cd 100644
--- a/backend/tests/unit/test_one_drive_service.py
+++ b/backend/tests/unit/test_one_drive_service.py
@@ -24,7 +24,7 @@ def service():
 def test_user(db: Session) -> User:
     """Create a test user."""
     user = User(
-        email="test@example.com",
+        email=f"test_onedrive_service_{uuid.uuid4()}@example.com",
         hashed_password="hashed",
         first_name="Test",
         last_name="User",