diff --git a/src/pipecat/serializers/base_serializer.py b/src/pipecat/serializers/base_serializer.py
index f57165034..5bd1182fe 100644
--- a/src/pipecat/serializers/base_serializer.py
+++ b/src/pipecat/serializers/base_serializer.py
@@ -18,10 +18,12 @@ class FrameSerializerType(Enum):
     Parameters:
         BINARY: Binary serialization format for compact representation.
         TEXT: Text-based serialization format for human-readable output.
+        MIXED: Mixed format supporting both binary and text messages (e.g., Vonage).
     """
 
     BINARY = "binary"
     TEXT = "text"
+    MIXED = "mixed"
 
 
 class FrameSerializer(ABC):