diff --git a/vllm/model_executor/layers/mamba/ops/causal_conv1d.py b/vllm/model_executor/layers/mamba/ops/causal_conv1d.py
index 6793f6def2b7..a8bd0067bf45 100644
--- a/vllm/model_executor/layers/mamba/ops/causal_conv1d.py
+++ b/vllm/model_executor/layers/mamba/ops/causal_conv1d.py
@@ -92,7 +92,8 @@ def _causal_conv1d_fwd_kernel(  # continuous batching
 
     if IS_CONTINUOUS_BATCHING:
         # cache_idx
-        conv_state_batch_coord = tl.load(conv_state_indices_ptr + idx_seq)
+        conv_state_batch_coord = tl.load(conv_state_indices_ptr + idx_seq).to(
+            tl.int64)
     else:
         # cache_idx
         conv_state_batch_coord = idx_seq