diff --git a/tpu_inference/platforms/tpu_platform.py b/tpu_inference/platforms/tpu_platform.py
index 09522b5bcd..9f2a785264 100644
--- a/tpu_inference/platforms/tpu_platform.py
+++ b/tpu_inference/platforms/tpu_platform.py
@@ -8,7 +8,6 @@
 from tpu_info import device
 from vllm.inputs import ProcessorInputs, PromptType
 from vllm.platforms.interface import Platform, PlatformEnum
-from vllm.sampling_params import SamplingParams, SamplingType
 
 from tpu_inference import envs
 from tpu_inference.layers.common.sharding import ShardingConfigManager
@@ -19,12 +18,15 @@
     from vllm.attention.backends.registry import AttentionBackendEnum
     from vllm.config import BlockSize, ModelConfig, VllmConfig
     from vllm.pooling_params import PoolingParams
+    from vllm.sampling_params import SamplingParams, SamplingType
 else:
     BlockSize = None
     ModelConfig = None
     VllmConfig = None
     PoolingParams = None
     AttentionBackendEnum = None
+    SamplingParams = None
+    SamplingType = None
 
 logger = init_logger(__name__)
 
@@ -250,10 +252,11 @@ def supports_v1(cls, model_config: ModelConfig) -> bool:
     def validate_request(
         cls,
         prompt: PromptType,
-        params: Union[SamplingParams, PoolingParams],
+        params: Union["SamplingParams", PoolingParams],
         processed_inputs: ProcessorInputs,
     ) -> None:
         """Raises if this request is unsupported on this platform"""
+        from vllm.sampling_params import SamplingParams, SamplingType
 
         if isinstance(params, SamplingParams):
             if params.sampling_type == SamplingType.RANDOM_SEED: