diff --git a/vllm/config.py b/vllm/config.py
index f3dcd9f0d7afc..e381eef73da05 100644
--- a/vllm/config.py
+++ b/vllm/config.py
@@ -5,9 +5,9 @@
                     Mapping, Optional, Set, Tuple, Type, Union)
 
 import torch
+from transformers import PretrainedConfig
 
 import vllm.envs as envs
-from transformers import PretrainedConfig
 from vllm.logger import init_logger
 from vllm.model_executor.layers.pooler import PoolingConfig, PoolingType
 from vllm.model_executor.layers.quantization import QUANTIZATION_METHODS
@@ -420,7 +420,8 @@ def _verify_bnb_config(self) -> None:
                 "fallback to the eager mode.")
             self.enforce_eager = True
 
-    def get_pooling_type(self, pooling_type_name: str) -> PoolingType:
+    def get_pooling_type(self,
+                         pooling_type_name: str) -> Optional[PoolingType]:
         pooling_types = {i.name: i for i in PoolingType}
         return pooling_types.get(pooling_type_name)
 
diff --git a/vllm/transformers_utils/config.py b/vllm/transformers_utils/config.py
index f4dd98ced80ee..2ee24471dc0a9 100644
--- a/vllm/transformers_utils/config.py
+++ b/vllm/transformers_utils/config.py
@@ -9,13 +9,13 @@
 from huggingface_hub.utils import (EntryNotFoundError, LocalEntryNotFoundError,
                                    RepositoryNotFoundError,
                                    RevisionNotFoundError)
+from transformers import GenerationConfig, PretrainedConfig
 from transformers.models.auto.image_processing_auto import (
     get_image_processor_config)
 from transformers.models.auto.modeling_auto import (
     MODEL_FOR_CAUSAL_LM_MAPPING_NAMES)
 from transformers.utils import CONFIG_NAME as HF_CONFIG_NAME
 
-from transformers import GenerationConfig, PretrainedConfig
 from vllm.envs import VLLM_USE_MODELSCOPE
 from vllm.logger import init_logger
 from vllm.model_executor.layers.pooler import PoolingType