diff --git a/backend/chainlit/config.py b/backend/chainlit/config.py
index d59da1bca1..5a0d2c4178 100644
--- a/backend/chainlit/config.py
+++ b/backend/chainlit/config.py
@@ -400,7 +400,7 @@ def init_config(log=False):
             dst = os.path.join(config_translation_dir, file)
             if not os.path.exists(dst):
                 src = os.path.join(TRANSLATIONS_DIR, file)
-                with open(src, "r", encoding="utf-8") as f:
+                with open(src, encoding="utf-8") as f:
                     translation = json.load(f)
                     with open(dst, "w", encoding="utf-8") as f:
                         json.dump(translation, f, indent=4)
@@ -515,7 +515,7 @@ def load_config():
 def lint_translations():
     # Load the ground truth (en-US.json file from chainlit source code)
     src = os.path.join(TRANSLATIONS_DIR, "en-US.json")
-    with open(src, "r", encoding="utf-8") as f:
+    with open(src, encoding="utf-8") as f:
         truth = json.load(f)
 
         # Find the local app translations
@@ -523,7 +523,7 @@ def lint_translations():
             if file.endswith(".json"):
                 # Load the translation file
                 to_lint = os.path.join(config_translation_dir, file)
-                with open(to_lint, "r", encoding="utf-8") as f:
+                with open(to_lint, encoding="utf-8") as f:
                     translation = json.load(f)
 
                     # Lint the translation file
diff --git a/backend/chainlit/data/sql_alchemy.py b/backend/chainlit/data/sql_alchemy.py
index 9ed62a3bb2..5a694b081f 100644
--- a/backend/chainlit/data/sql_alchemy.py
+++ b/backend/chainlit/data/sql_alchemy.py
@@ -168,7 +168,7 @@ async def _get_user_id_by_thread(self, thread_id: str) -> Optional[str]:
     async def create_user(self, user: User) -> Optional[PersistedUser]:
         if self.show_logger:
             logger.info(f"SQLAlchemy: create_user, user_identifier={user.identifier}")
-        existing_user: Optional["PersistedUser"] = await self.get_user(user.identifier)
+        existing_user: Optional[PersistedUser] = await self.get_user(user.identifier)
         user_dict: Dict[str, Any] = {
             "identifier": str(user.identifier),
             "metadata": json.dumps(user.metadata) or {},
diff --git a/backend/chainlit/emitter.py b/backend/chainlit/emitter.py
index 5cc6a905b6..1f1950ad63 100644
--- a/backend/chainlit/emitter.py
+++ b/backend/chainlit/emitter.py
@@ -289,7 +289,7 @@ async def send_ask_user(
             await self.task_end()
 
             final_res: Optional[
-                Union["StepDict", "AskActionResponse", List["FileDict"]]
+                Union[StepDict, AskActionResponse, List[FileDict]]
             ] = None
 
             if user_res:
diff --git a/backend/chainlit/langchain/callbacks.py b/backend/chainlit/langchain/callbacks.py
index 7449663dd4..526002cd36 100644
--- a/backend/chainlit/langchain/callbacks.py
+++ b/backend/chainlit/langchain/callbacks.py
@@ -468,7 +468,7 @@ async def _start_trace(self, run: Run) -> None:
         if ignore:
             return
 
-        step_type: "TrueStepType" = "undefined"
+        step_type: TrueStepType = "undefined"
         if run.run_type == "agent":
             step_type = "run"
         elif run.run_type == "chain":
diff --git a/backend/chainlit/secret.py b/backend/chainlit/secret.py
index 968193bf16..cc85257abe 100644
--- a/backend/chainlit/secret.py
+++ b/backend/chainlit/secret.py
@@ -6,4 +6,4 @@
 
 
 def random_secret(length: int = 64):
-    return "".join((secrets.choice(chars) for i in range(length)))
+    return "".join(secrets.choice(chars) for i in range(length))
diff --git a/backend/chainlit/server.py b/backend/chainlit/server.py
index bee77bb2f6..259cf57e14 100644
--- a/backend/chainlit/server.py
+++ b/backend/chainlit/server.py
@@ -317,7 +317,7 @@ def get_html_template():
 
     index_html_file_path = os.path.join(build_dir, "index.html")
 
-    with open(index_html_file_path, "r", encoding="utf-8") as f:
+    with open(index_html_file_path, encoding="utf-8") as f:
         content = f.read()
         content = content.replace(PLACEHOLDER, tags)
         if js:
diff --git a/backend/chainlit/session.py b/backend/chainlit/session.py
index 95a34cf8ad..404713ec92 100644
--- a/backend/chainlit/session.py
+++ b/backend/chainlit/session.py
@@ -18,9 +18,9 @@
 
 
 class JSONEncoderIgnoreNonSerializable(json.JSONEncoder):
-    def default(self, obj):
+    def default(self, o):
         try:
-            return super(JSONEncoderIgnoreNonSerializable, self).default(obj)
+            return super().default(o)
         except TypeError:
             return None
 
diff --git a/backend/pyproject.toml b/backend/pyproject.toml
index ff152e7d87..3aebd47de8 100644
--- a/backend/pyproject.toml
+++ b/backend/pyproject.toml
@@ -145,8 +145,8 @@ target-version = "py39"
 line-length = 120
 
 [tool.ruff.lint]
-select = ["E", "F", "I", "LOG"]
-ignore = ["E712", "E501"]
+select = ["E", "F", "I", "LOG", "UP"]
+ignore = ["E712", "E501", "UP006", "UP035"]
 
 [tool.ruff.lint.isort]
 combine-as-imports = true