diff --git a/packages/atproto_firehose/models.py b/packages/atproto_firehose/models.py
index 375dd43b..0cd3f2a7 100644
--- a/packages/atproto_firehose/models.py
+++ b/packages/atproto_firehose/models.py
@@ -15,10 +15,6 @@ class FrameType(Enum):
     MESSAGE = 1
     ERROR = -1
 
-    @classmethod
-    def has_value(cls, value: int) -> bool:
-        return value in cls._value2member_map_
-
 
 @dataclass
 class MessageFrameHeader:
@@ -50,13 +46,12 @@ class ErrorFrameBody:
 def parse_frame_header(raw_header: dict) -> FrameHeader:
     try:
         header_op = int(raw_header.get('op', 0))
-        if not FrameType.has_value(header_op):
-            raise FirehoseDecodingError('Invalid frame type')
-
-        frame_type = FrameType(header_op)
-        if frame_type is FrameType.MESSAGE:
+        if header_op == FrameType.MESSAGE.value:
             return get_or_create(raw_header, MessageFrameHeader)
-        return get_or_create(raw_header, ErrorFrameHeader)
+        elif header_op == FrameType.ERROR.value:
+            return get_or_create(raw_header, ErrorFrameHeader)
+        else:
+            raise FirehoseDecodingError('Invalid frame type')
     except (ValueError, AtProtocolError) as e:
         raise FirehoseDecodingError('Invalid frame header') from e
 
@@ -106,23 +101,16 @@ def from_bytes(data: Union[bytes, bytearray]) -> Union['MessageFrame', 'ErrorFra
             :obj:`atproto.firehose_models.MessageFrame` or :obj:`atproto.firehose_models.ErrorFrame`
 
         Raises:
-            :class:`atproto.exceptions.FirehoseError`: Invalid data frame.
+            :class:`atproto.exceptions.FirehoseDecodingError`: Invalid data frame.
         """
         decoded_parts = decode_dag_multi(data)
+        if not decoded_parts:
+            raise FirehoseDecodingError('Invalid frame without CBOR data')
         if len(decoded_parts) > 2:
             raise FirehoseDecodingError('Too many CBOR data parts in the frame')
-        if not len(decoded_parts):
-            raise FirehoseDecodingError('Invalid frame without CBOR data')
-
-        raw_header = decoded_parts[0]
-
-        raw_body = None
-        if len(decoded_parts) > 1:
-            raw_body = decoded_parts[1]
-
-        if raw_body is None:
+        if len(decoded_parts) < 2:
             raise FirehoseDecodingError('Frame body not found')
-
+        raw_header, raw_body = decoded_parts
         header = parse_frame_header(raw_header)
         return parse_frame(header, raw_body)