diff --git a/tensorrt_llm/_torch/auto_deploy/custom_ops/mamba/cuda_backend_causal_conv.py b/tensorrt_llm/_torch/auto_deploy/custom_ops/mamba/cuda_backend_causal_conv.py
index 0803375847f..dfe39ce08dd 100644
--- a/tensorrt_llm/_torch/auto_deploy/custom_ops/mamba/cuda_backend_causal_conv.py
+++ b/tensorrt_llm/_torch/auto_deploy/custom_ops/mamba/cuda_backend_causal_conv.py
@@ -283,7 +283,7 @@ def _get_conv_cache(si: SequenceInfo):
                 in_channels,
                 max(1, kernel_size - 1),
                 device=si.device,
-                dtype=cache_config.dtype or inp_fake.dtype,
+                dtype=inp_fake.dtype,
             )
 
         return {"conv_state_cache": _get_conv_cache}
diff --git a/tensorrt_llm/_torch/auto_deploy/custom_ops/mamba/torch_backend_causal_conv.py b/tensorrt_llm/_torch/auto_deploy/custom_ops/mamba/torch_backend_causal_conv.py
index 6f0059d250d..67913a324c0 100644
--- a/tensorrt_llm/_torch/auto_deploy/custom_ops/mamba/torch_backend_causal_conv.py
+++ b/tensorrt_llm/_torch/auto_deploy/custom_ops/mamba/torch_backend_causal_conv.py
@@ -341,7 +341,7 @@ def _get_conv_cache(si: SequenceInfo):
                 in_channels,
                 kernel_size,
                 device=si.device,
-                dtype=cache_config.dtype or inp_fake.dtype,
+                dtype=inp_fake.dtype,
             )
 
         return {"conv_state_cache": _get_conv_cache}