diff --git a/src/operator/contrib/roi_align.cc b/src/operator/contrib/roi_align.cc
index dc4aa8b7de9e..e584ea30325d 100644
--- a/src/operator/contrib/roi_align.cc
+++ b/src/operator/contrib/roi_align.cc
@@ -157,10 +157,9 @@ void ROIAlignForward(
   int n_rois = nthreads / channels / pooled_width / pooled_height;
   // (n, c, ph, pw) is an element in the pooled output
   // can be parallelized using omp
-  int n;
-#pragma omp parallel for private(n) \
+#pragma omp parallel for \
 num_threads(engine::OpenMP::Get()->GetRecommendedOMPThreadCount())
-  for (n = 0; n < n_rois; n++) {
+  for (int n = 0; n < n_rois; n++) {
     int index_n = n * channels * pooled_width * pooled_height;
 
     // roi could have 4 or 5 columns
@@ -564,7 +563,8 @@ He, Kaiming, et al. "Mask R-CNN." ICCV, 2017
   out_shape->clear();
   if (param.position_sensitive) {
     CHECK_EQ(dshape[1] % (param.pooled_size[0]*param.pooled_size[1]), 0) <<
-      "Input channels should be divided by pooled_size[0]*pooled_size[1]";
+      "Input channels should be divided by pooled_size[0]*pooled_size[1]"
+      "when position_sensitive is true.";
     out_shape->push_back(
          Shape4(bshape[0], dshape[1]/param.pooled_size[0]/param.pooled_size[1],
                 param.pooled_size[0], param.pooled_size[1]));