diff --git a/CHANGELOG.md b/CHANGELOG.md
index 661e0bb2a..a297b8d3f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   the Telnyx call when an `EndFrame` or `CancelFrame` is received. It is
   enabled by default and is configurable via the `auto_hang_up` `InputParam`.
 
+### Changed
+
+- In `TwilioFrameSerializer`, `call_sid` is Optional so as to avoid a breaking
+  changed. `call_sid` is required to automatically hang up.
+
 ### Fixed
 
 - Fixed an issue where `TwilioFrameSerializer` would send two hang up commands:
diff --git a/src/pipecat/serializers/twilio.py b/src/pipecat/serializers/twilio.py
index 3c4c2a2c9..b169955ce 100644
--- a/src/pipecat/serializers/twilio.py
+++ b/src/pipecat/serializers/twilio.py
@@ -66,7 +66,7 @@ class TwilioFrameSerializer(FrameSerializer):
     def __init__(
         self,
         stream_sid: str,
-        call_sid: str,
+        call_sid: Optional[str] = None,
         account_sid: Optional[str] = None,
         auth_token: Optional[str] = None,
         params: InputParams = InputParams(),
@@ -75,9 +75,9 @@ class TwilioFrameSerializer(FrameSerializer):
 
         Args:
             stream_sid: The Twilio Media Stream SID.
-            call_sid: The associated Twilio Call SID.
-            account_sid: Twilio account SID.
-            auth_token: Twilio auth token.
+            call_sid: The associated Twilio Call SID (optional, but required for auto hang-up).
+            account_sid: Twilio account SID (required for auto hang-up).
+            auth_token: Twilio auth token (required for auto hang-up).
             params: Configuration parameters.
         """
         self._stream_sid = stream_sid
@@ -160,15 +160,26 @@ class TwilioFrameSerializer(FrameSerializer):
 
             account_sid = self._account_sid
             auth_token = self._auth_token
+            call_sid = self._call_sid
+
+            if not call_sid or not account_sid or not auth_token:
+                missing = []
+                if not call_sid:
+                    missing.append("call_sid")
+                if not account_sid:
+                    missing.append("account_sid")
+                if not auth_token:
+                    missing.append("auth_token")
 
-            if not account_sid or not auth_token:
                 logger.warning(
-                    "Cannot hang up Twilio call: account_sid and auth_token must be provided"
+                    f"Cannot hang up Twilio call: missing required parameters: {', '.join(missing)}"
                 )
                 return
 
             # Twilio API endpoint for updating calls
-            endpoint = f"https://api.twilio.com/2010-04-01/Accounts/{account_sid}/Calls/{self._call_sid}.json"
+            endpoint = (
+                f"https://api.twilio.com/2010-04-01/Accounts/{account_sid}/Calls/{call_sid}.json"
+            )
 
             # Create basic auth from account_sid and auth_token
             auth = aiohttp.BasicAuth(account_sid, auth_token)
@@ -180,12 +191,12 @@ class TwilioFrameSerializer(FrameSerializer):
             async with aiohttp.ClientSession() as session:
                 async with session.post(endpoint, auth=auth, data=params) as response:
                     if response.status == 200:
-                        logger.info(f"Successfully terminated Twilio call {self._call_sid}")
+                        logger.info(f"Successfully terminated Twilio call {call_sid}")
                     else:
                         # Get the error details for better debugging
                         error_text = await response.text()
                         logger.error(
-                            f"Failed to terminate Twilio call {self._call_sid}: "
+                            f"Failed to terminate Twilio call {call_sid}: "
                             f"Status {response.status}, Response: {error_text}"
                         )