diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorContractionThreadPool.h b/unsupported/Eigen/CXX11/src/Tensor/TensorContractionThreadPool.h
index 88d485f38..d6af6fedd 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorContractionThreadPool.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorContractionThreadPool.h
@@ -273,7 +273,7 @@ struct TensorEvaluator<const TensorContractionOp<Indices, LeftArgType, RightArgT
     // First, we are interested in parallel packing if there are few tasks.
     bool parallel_pack = num_threads >= nm * nn;
     // Also do parallel packing if all data fits into L2$.
-    if (m * bk * sizeof(LhsScalar) + n * bk * sizeof(RhsScalar) <=
+    if (m * bk * Index(sizeof(LhsScalar)) + n * bk * Index(sizeof(RhsScalar)) <=
         l2CacheSize() * num_threads)
       parallel_pack = true;
     // But don't do it if we will use each rhs only once. Locality seems to be
@@ -361,7 +361,7 @@ struct TensorEvaluator<const TensorContractionOp<Indices, LeftArgType, RightArgT
       packed_mem_ = static_cast<char*>(internal::aligned_malloc(
           (nm0_ * lhs_size + nn0_ * rhs_size) * std::min<size_t>(nk_, P - 1)));
       char* mem = static_cast<char*>(packed_mem_);
-      for (Index x = 0; x < numext::mini<size_t>(nk_, P - 1); x++) {
+      for (Index x = 0; x < numext::mini<Index>(nk_, P - 1); x++) {
         packed_lhs_[x].resize(nm0_);
         for (Index m = 0; m < nm0_; m++) {
           packed_lhs_[x][m] = reinterpret_cast<LhsScalar*>(mem);