diff --git a/tests/v1/engine/test_engine_core.py b/tests/v1/engine/test_engine_core.py
index 8451aac33acc4..b3692b594326a 100644
--- a/tests/v1/engine/test_engine_core.py
+++ b/tests/v1/engine/test_engine_core.py
@@ -27,6 +27,9 @@ def make_request() -> EngineCoreRequest:
         request_id=uuid.uuid4(),
         prompt=PROMPT,
         prompt_token_ids=PROMPT_TOKENS,
+        mm_data=None,
+        mm_placeholders=None,
+        mm_processor_kwargs=None,
         sampling_params=SamplingParams(),
         eos_token_id=None,
         arrival_time=time.time(),
diff --git a/tests/v1/engine/test_engine_core_client.py b/tests/v1/engine/test_engine_core_client.py
index d582101a1164f..7b241bf836a0e 100644
--- a/tests/v1/engine/test_engine_core_client.py
+++ b/tests/v1/engine/test_engine_core_client.py
@@ -29,6 +29,9 @@ def make_request(params: SamplingParams) -> EngineCoreRequest:
         request_id=str(uuid.uuid4()),
         prompt=PROMPT,
         prompt_token_ids=PROMPT_TOKENS,
+        mm_data=None,
+        mm_placeholders=None,
+        mm_processor_kwargs=None,
         sampling_params=params,
         eos_token_id=None,
         arrival_time=time.time(),
diff --git a/vllm/v1/engine/core.py b/vllm/v1/engine/core.py
index 808c3936b6c35..428483bdb29cb 100644
--- a/vllm/v1/engine/core.py
+++ b/vllm/v1/engine/core.py
@@ -317,7 +317,7 @@ def process_input_socket(self, input_path: str):
 
         # Msgpack serialization decoding.
         decoder_add_req = PickleEncoder()
-        decoder_abort_req = msgpack.Decoder(list[str])
+        decoder_abort_req = PickleEncoder()
 
         with self.make_socket(input_path, zmq.constants.PULL) as socket:
             while True: