diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorContraction.h b/unsupported/Eigen/CXX11/src/Tensor/TensorContraction.h
index fa62b25c2..9e208934b 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorContraction.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorContraction.h
@@ -495,7 +495,7 @@ struct TensorContractionEvaluatorBase
       internal::array_size<typename TensorEvaluator<EvalLeftArgType, Device>::Dimensions>::value;
   static const int RDims =
       internal::array_size<typename TensorEvaluator<EvalRightArgType, Device>::Dimensions>::value;
-  static const unsigned int ContractDims = internal::array_size<Indices>::value;
+  static const int ContractDims = internal::array_size<Indices>::value;
   static const int NumDims = max_n_1<LDims + RDims - 2 * ContractDims>::size;
 
   typedef array<Index, LDims> left_dim_mapper_t;
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorDimensions.h b/unsupported/Eigen/CXX11/src/Tensor/TensorDimensions.h
index 114871f49..f3c9a3148 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorDimensions.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorDimensions.h
@@ -265,10 +265,10 @@ struct tensor_index_linearization_helper<Index, NumIndices, 0, RowMajor>
 
 
 // Dynamic size
-template <typename DenseIndex, std::size_t NumDims>
+template <typename DenseIndex, int NumDims>
 struct DSizes : array<DenseIndex, NumDims> {
   typedef array<DenseIndex, NumDims> Base;
-  static const std::size_t count = NumDims;
+  static const int count = NumDims;
 
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE size_t rank() const {
     return NumDims;
@@ -278,8 +278,8 @@ struct DSizes : array<DenseIndex, NumDims> {
     return internal::array_prod(*static_cast<const Base*>(this));
   }
 
-  EIGEN_DEVICE_FUNC DSizes() {
-    for (std::size_t i = 0 ; i < NumDims; ++i) {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE DSizes() {
+    for (int i = 0 ; i < NumDims; ++i) {
       (*this)[i] = 0;
     }
   }
@@ -369,10 +369,10 @@ struct tensor_vsize_index_linearization_helper<Index, NumIndices, 0, RowMajor>
 
 namespace internal {
 
-template <typename DenseIndex, std::size_t NumDims> struct array_size<const DSizes<DenseIndex, NumDims> > {
+template <typename DenseIndex, int NumDims> struct array_size<const DSizes<DenseIndex, NumDims> > {
   static const size_t value = NumDims;
 };
-template <typename DenseIndex, std::size_t NumDims> struct array_size<DSizes<DenseIndex, NumDims> > {
+template <typename DenseIndex, int NumDims> struct array_size<DSizes<DenseIndex, NumDims> > {
   static const size_t value = NumDims;
 };
 #ifndef EIGEN_EMULATE_CXX11_META_H
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorStorage.h b/unsupported/Eigen/CXX11/src/Tensor/TensorStorage.h
index ee6f14b8f..98631fc7f 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorStorage.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorStorage.h
@@ -63,7 +63,7 @@ class TensorStorage<T, FixedDimensions, Options_>
 
 
 // pure dynamic
-template<typename T, int Options_, typename IndexType, std::size_t NumIndices_>
+template<typename T, int Options_, typename IndexType, int NumIndices_>
 class TensorStorage<T, DSizes<IndexType, NumIndices_>, Options_>
 {
   public: