diff --git a/pcdet/ops/iou3d_nms/src/iou3d_cpu.h b/pcdet/ops/iou3d_nms/src/iou3d_cpu.h
new file mode 100644
index 0000000..4d93bb6
--- /dev/null
+++ b/pcdet/ops/iou3d_nms/src/iou3d_cpu.h
@@ -0,0 +1,11 @@
+#ifndef IOU3D_CPU_H
+#define IOU3D_CPU_H
+
+#include <torch/serialize/tensor.h>
+#include <vector>
+#include <cuda.h>
+#include <cuda_runtime_api.h>
+
+int boxes_iou_bev_cpu(at::Tensor boxes_a_tensor, at::Tensor boxes_b_tensor, at::Tensor ans_iou_tensor);
+int boxes_aligned_iou_bev_cpu(at::Tensor boxes_a_tensor, at::Tensor boxes_b_tensor, at::Tensor ans_iou_tensor);
+#endif