diff --git a/src/preprocess_kernels.cu b/src/preprocess_kernels.cu
index 030c683..5228d19 100644
--- a/src/preprocess_kernels.cu
+++ b/src/preprocess_kernels.cu
@@ -146,6 +146,8 @@ __global__ void generateBaseFeatures_kernel(unsigned int *mask, float *voxels,
   unsigned int current_pillarId = 0;
   current_pillarId = atomicAdd(pillar_num, 1);
 
+  if( current_pillarId >= MAX_VOXELS ) return;
+  
   voxel_num[current_pillarId] = count;
 
   uint4 idx = {0, 0, voxel_idy, voxel_idx};
@@ -194,10 +196,10 @@ __global__ void generateFeatures_kernel(float* voxel_features,
     int pillar_idx = blockIdx.x * WARPS_PER_BLOCK + threadIdx.x/WARP_SIZE;
     int point_idx = threadIdx.x % WARP_SIZE;
 
-    int pillar_idx_inBlock = threadIdx.x/32;
+    int pillar_idx_inBlock = threadIdx.x/WARP_SIZE;
     unsigned int num_pillars = params[0];
 
-    if (pillar_idx >= num_pillars) return;
+    if (pillar_idx >= num_pillars || pillar_idx >= MAX_VOXELS) return;
 
     __shared__ float4 pillarSM[WARPS_PER_BLOCK][WARP_SIZE];
     __shared__ float4 pillarSumSM[WARPS_PER_BLOCK];