diff --git a/python/sglang/srt/layers/attention/aiter_backend.py b/python/sglang/srt/layers/attention/aiter_backend.py
index 44427ec81a2e..7833c2494cb1 100755
--- a/python/sglang/srt/layers/attention/aiter_backend.py
+++ b/python/sglang/srt/layers/attention/aiter_backend.py
@@ -2503,7 +2503,7 @@ def forward_decode(
 
                 o = torch.empty_like(q, dtype=self.input_dtype)
 
-                max_kv_len = page_table.shape[1]
+                max_kv_len = page_table.shape[1] * self.page_size
 
                 unified_attention(
                     q=q.view(-1, layer.tp_q_head_num, layer.qk_head_dim),