diff --git a/btas/generic/gemm_impl.h b/btas/generic/gemm_impl.h
index bbd3a357..b17f3b21 100644
--- a/btas/generic/gemm_impl.h
+++ b/btas/generic/gemm_impl.h
@@ -508,7 +508,7 @@ void gemm (
       scal(beta, C);
       return;
    }
-   
+
    typedef typename _TensorA::value_type value_type;
    assert(not ((transA == CblasConjTrans || transB == CblasConjTrans) && std::is_fundamental<value_type>::value));
 
diff --git a/btas/generic/permute.h b/btas/generic/permute.h
index 55ede85c..f50aadb3 100644
--- a/btas/generic/permute.h
+++ b/btas/generic/permute.h
@@ -21,8 +21,8 @@ namespace btas {
                                            is_boxtensor<_TensorY>::value
                                           >::type
           >
-  void 
-  permute(const _TensorX& X, const _Permutation& p, _TensorY& Y) 
+  void
+  permute(const _TensorX& X, const _Permutation& p, _TensorY& Y)
     {
     const auto pr = permute(X.range(),p);
     Y.resize(pr);
diff --git a/btas/storage_traits.h b/btas/storage_traits.h
index ebf0ea30..0c10ae6f 100644
--- a/btas/storage_traits.h
+++ b/btas/storage_traits.h
@@ -8,6 +8,8 @@
 #ifndef BTAS_STORAGE_TRAITS_H_
 #define BTAS_STORAGE_TRAITS_H_
 
+#include <valarray>
+
 #include <btas/index_traits.h>
 
 namespace btas {
@@ -43,6 +45,18 @@ namespace btas {
       typedef const_pointer const_iterator;
   };
 
+  template <typename _T>
+  struct storage_traits<std::valarray<_T>> {
+      typedef _T value_type;
+      typedef _T& reference;
+      typedef const _T& const_reference;
+      typedef size_t size_type;
+      typedef ptrdiff_t difference_type;
+
+      typedef _T* iterator;
+      typedef typename std::add_const<_T*>::type const_iterator;
+  };
+
   template <typename _Storage>
   struct storage_traits {
       typedef typename _Storage::value_type value_type;
diff --git a/btas/tensor.h b/btas/tensor.h
index 35e68976..d86ab811 100644
--- a/btas/tensor.h
+++ b/btas/tensor.h
@@ -54,13 +54,13 @@ namespace btas {
       typedef const value_type& const_reference;
 
       /// element iterator
-      typedef typename storage_type::iterator iterator;
+      typedef typename storage_traits<storage_type>::iterator iterator;
 
       /// constant element iterator
-      typedef typename storage_type::const_iterator const_iterator;
+      typedef typename storage_traits<storage_type>::const_iterator const_iterator;
 
       /// size type
-      typedef typename storage_type::size_type size_type;
+      typedef typename storage_traits<storage_type>::size_type size_type;
 
       ///@}
 
diff --git a/unittest/tensor_test.cc b/unittest/tensor_test.cc
index cf118e35..3d0961f1 100644
--- a/unittest/tensor_test.cc
+++ b/unittest/tensor_test.cc
@@ -160,7 +160,35 @@ TEST_CASE("Tensor Constructors")
         }
     }
 
-TEST_CASE("Tensor")
+TEST_CASE("Custom Tensor")
+    {
+
+    SECTION("Storage")
+        {
+          {
+          typedef Tensor<double, btas::DEFAULT::range, std::vector<double> > Tensor;
+          Tensor T0;
+          Tensor T1(2,3,4);
+          }
+          {
+          typedef Tensor<double, btas::DEFAULT::range, btas::varray<double> > Tensor;
+          Tensor T0;
+          Tensor T1(2,3,4);
+          }
+          {
+          typedef Tensor<double, btas::DEFAULT::range, std::array<double, 24> > Tensor;
+          Tensor T0;
+          Tensor T1(2,3,4);
+          }
+          {
+          typedef Tensor<double, btas::DEFAULT::range, std::valarray<double> > Tensor;
+          Tensor T0;
+          Tensor T1(2,3,4);
+          }
+        }
+    }
+
+TEST_CASE("Tensor Operations")
     {
     DTensor T2(3,2);
     fillEls(T2);