diff --git a/backend/app/api/routes/settings.py b/backend/app/api/routes/settings.py
index 973811c35..4d895c2a0 100644
--- a/backend/app/api/routes/settings.py
+++ b/backend/app/api/routes/settings.py
@@ -34,17 +34,17 @@ async def get_setting(db: AsyncSession, key: str) -> str | None:
 
 async def get_external_login_url(db: AsyncSession) -> str:
     """Get the external URL for the login page.
-    
+
     Uses external_url from settings if available, otherwise falls back to APP_URL env var.
-    
+
     Args:
         db: Database session
-        
+
     Returns:
         Full URL to the login page
     """
     import os
-    
+
     external_url = await get_setting(db, "external_url")
     if external_url:
         external_url = external_url.rstrip("/")
diff --git a/backend/app/api/routes/users.py b/backend/app/api/routes/users.py
index 20c2fce3d..611486f4e 100644
--- a/backend/app/api/routes/users.py
+++ b/backend/app/api/routes/users.py
@@ -80,9 +80,7 @@ async def create_user(
     advanced_auth_enabled = advanced_auth_setting and advanced_auth_setting.value.lower() == "true"
 
     # Check if username already exists (case-insensitive)
-    existing_user = await db.execute(
-        select(User).where(func.lower(User.username) == func.lower(user_data.username))
-    )
+    existing_user = await db.execute(select(User).where(func.lower(User.username) == func.lower(user_data.username)))
     if existing_user.scalar_one_or_none():
         raise HTTPException(
             status_code=status.HTTP_400_BAD_REQUEST,
@@ -104,9 +102,7 @@ async def create_user(
                 detail="Email is required when advanced authentication is enabled",
             )
         # Check if email already exists (case-insensitive)
-        existing_email = await db.execute(
-            select(User).where(func.lower(User.email) == func.lower(user_data.email))
-        )
+        existing_email = await db.execute(select(User).where(func.lower(User.email) == func.lower(user_data.email)))
         if existing_email.scalar_one_or_none():
             raise HTTPException(
                 status_code=status.HTTP_400_BAD_REQUEST,
diff --git a/backend/app/core/auth.py b/backend/app/core/auth.py
index 99690e8f6..0f1d546a0 100644
--- a/backend/app/core/auth.py
+++ b/backend/app/core/auth.py
@@ -145,7 +145,7 @@ async def get_user_by_email(db: AsyncSession, email: str) -> User | None:
 
 async def authenticate_user(db: AsyncSession, username: str, password: str) -> User | None:
     """Authenticate a user by username and password.
-    
+
     Username lookup is case-insensitive. Password is case-sensitive.
     """
     user = await get_user_by_username(db, username)
@@ -160,7 +160,7 @@ async def authenticate_user(db: AsyncSession, username: str, password: str) -> U
 
 async def authenticate_user_by_email(db: AsyncSession, email: str, password: str) -> User | None:
     """Authenticate a user by email and password.
-    
+
     Email lookup is case-insensitive. Password is case-sensitive.
     """
     user = await get_user_by_email(db, email)
diff --git a/backend/tests/integration/test_auth_api.py b/backend/tests/integration/test_auth_api.py
index ba1bfa4b4..97d717484 100644
--- a/backend/tests/integration/test_auth_api.py
+++ b/backend/tests/integration/test_auth_api.py
@@ -798,6 +798,6 @@ class TestAuthMiddlewarePublicRoutes:
         )
         # Should not be 401 (must be accessible for password reset from login page)
         assert response.status_code != 401
-        # Will likely be 400 (advanced auth not enabled) but that's okay - 
+        # Will likely be 400 (advanced auth not enabled) but that's okay -
         # the important thing is it's not blocked by auth middleware
         assert response.status_code in [200, 400]