diff --git a/python/sglang/test/attention/test_prefix_chunk_info.py b/python/sglang/test/attention/test_prefix_chunk_info.py
index 2b85b695b..c02d4d1d6 100644
--- a/python/sglang/test/attention/test_prefix_chunk_info.py
+++ b/python/sglang/test/attention/test_prefix_chunk_info.py
@@ -2,6 +2,8 @@ import unittest
 
 import torch
 
+from sglang.srt.layers.attention.flashattention_backend import FlashAttentionBackend
+from sglang.srt.layers.radix_attention import RadixAttention
 from sglang.srt.mem_cache.memory_pool import MLATokenToKVPool
 from sglang.srt.model_executor.forward_batch_info import ForwardBatch, ForwardMode
 from sglang.test.test_utils import CustomTestCase