diff --git a/vllm/model_executor/models/bert.py b/vllm/model_executor/models/bert.py
index 06051c81b301d..3df089e49e391 100644
--- a/vllm/model_executor/models/bert.py
+++ b/vllm/model_executor/models/bert.py
@@ -387,7 +387,7 @@ def __init__(
         config: BertConfig,
         cache_config: Optional[CacheConfig] = None,
         quant_config: Optional[QuantizationConfig] = None,
-        pooling_type
+        pooling_type: Optional = None
     ) -> None:
         super().__init__()
         self.model = BertModel(config, cache_config, quant_config)