diff --git a/GPU_version/vio/src/sparse_img_align_gpu.cpp b/GPU_version/vio/src/sparse_img_align_gpu.cpp
index f21c4e3..7f1e175 100644
--- a/GPU_version/vio/src/sparse_img_align_gpu.cpp
+++ b/GPU_version/vio/src/sparse_img_align_gpu.cpp
@@ -90,7 +90,8 @@ double SparseImgAlignGpu::computeResiduals(
     float H[9*300]={0};
     cl_float3 J[300]={0.0};
     float chi2_[300]={0.0};
-    residual_->write_buf(1,11,scale_);
+    float scale=(float)scale_;
+    residual_->write_buf(1,11,scale);
     residual_->reload_buf(1,10,chi2_);
     residual_->reload_buf(1,8,H);
     residual_->reload_buf(1,9,J);