diff --git a/src/TiledArray/external/btas.h b/src/TiledArray/external/btas.h
index fe84e6f0c6..c22afd3813 100644
--- a/src/TiledArray/external/btas.h
+++ b/src/TiledArray/external/btas.h
@@ -62,6 +62,13 @@ class boxrange_iteration_order<TiledArray::Range> {
   static constexpr int value = row_major;
 };
 
+template <typename T, typename A>
+class is_tensor<TiledArray::Tensor<T, A>> : public std::true_type {};
+
+template <typename T, typename R, typename O>
+class is_tensor<TiledArray::detail::TensorInterface<T, R, O>>
+    : public std::true_type {};
+
 }  // namespace btas
 
 namespace TiledArray {
diff --git a/tests/btas.cpp b/tests/btas.cpp
index 9c15540e9a..4e972cfc28 100644
--- a/tests/btas.cpp
+++ b/tests/btas.cpp
@@ -256,6 +256,21 @@ BOOST_AUTO_TEST_CASE_TEMPLATE(tensor_ctor, Tensor, tensor_types) {
   BOOST_REQUIRE_NO_THROW(Tensor t1 = t0);
   Tensor t1 = t0;
   BOOST_CHECK(t1.empty());
+
+  // can copy TA::Tensor to btas::Tensor
+  TA::Tensor<typename Tensor::value_type> ta_tensor(r);
+  BOOST_REQUIRE_NO_THROW(Tensor(ta_tensor));
+  Tensor t2(ta_tensor);
+  for (auto i : r) {
+    BOOST_CHECK_EQUAL(ta_tensor(i), t2(i));
+  }
+
+  // can copy TA::TensorInterface to btas::Tensor
+  BOOST_REQUIRE_NO_THROW(Tensor(ta_tensor.block(r.lobound(), r.upbound())));
+  Tensor t3(ta_tensor.block(r.lobound(), r.upbound()));
+  for (auto i : r) {
+    BOOST_CHECK_EQUAL(ta_tensor(i), t3(i));
+  }
 }
 
 BOOST_AUTO_TEST_CASE_TEMPLATE(copy, Array, array_types) {
diff --git a/tests/expressions_btas.cpp b/tests/expressions_btas.cpp
index 83ff4b1ed0..7b1ae422ce 100644
--- a/tests/expressions_btas.cpp
+++ b/tests/expressions_btas.cpp
@@ -23,6 +23,8 @@
  *
  */
 
+#include <TiledArray/config.h>
+
 #ifdef TILEDARRAY_HAS_BTAS
 #include "expressions_fixture.h"