diff --git a/mshadow/extension/slice_ex.h b/mshadow/extension/slice_ex.h
index 7f0052d5..7f464097 100644
--- a/mshadow/extension/slice_ex.h
+++ b/mshadow/extension/slice_ex.h
@@ -114,7 +114,7 @@ struct Plan<SliceExExp<SrcExp, Device, DType, srcdim>, DType> {
     }
     return src_.Eval(idx, j + begin_[srcdim-1]);
   }
-  MSHADOW_XINLINE DType &REval(index_t i, index_t j) const {
+  MSHADOW_XINLINE DType &REval(index_t i, index_t j) {
     index_t idx = 0;
     index_t stride = 1;
     #pragma unroll