diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h b/unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h
index 0d34f7ee6..981515f4b 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h
@@ -33,24 +33,19 @@ struct TensorUInt128
   HIGH high;
   LOW low;
 
+  template<typename OTHER_HIGH, typename OTHER_LOW>
   EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
-  TensorUInt128(int32_t x) : high(0), low(x) {
+  TensorUInt128(const TensorUInt128<OTHER_HIGH, OTHER_LOW>& other) : high(other.high), low(other.low) {
+    static_assert(sizeof(OTHER_HIGH) <= sizeof(HIGH), "high too wide");
+    static_assert(sizeof(OTHER_LOW) <= sizeof(LOW), "low too wide");
+  }
+
+  template<typename T>
+  EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
+  explicit TensorUInt128(const T& x) : high(0), low(x) {
     eigen_assert(x >= 0);
   }
-  EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
-  TensorUInt128(uint32_t x) : high(0), low(x) { }
-  EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
-  TensorUInt128(long x) : high(0), low(x) {
-    eigen_assert(x >= 0);
-  }
-  EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
-  TensorUInt128(unsigned long x) : high(0), low(x) { }
-  EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
-  TensorUInt128(int64_t x) : high(0), low(x) {
-    eigen_assert(x >= 0);
-  }
-  EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
-  TensorUInt128(uint64_t x) : high(0), low(x) { }
+
   EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   TensorUInt128(uint64_t y, uint64_t x) : high(y), low(x) { }
 
diff --git a/unsupported/test/cxx11_tensor_uint128.cpp b/unsupported/test/cxx11_tensor_uint128.cpp
index ee3767e58..424c70197 100644
--- a/unsupported/test/cxx11_tensor_uint128.cpp
+++ b/unsupported/test/cxx11_tensor_uint128.cpp
@@ -127,7 +127,7 @@ void test_misc2() {
 
       TensorUInt128<uint64_t, uint64_t> result = (TensorUInt128<uint64_t, static_val<0> >(shift, 0) / TensorUInt128<static_val<0>, uint64_t>(divider) - TensorUInt128<static_val<1>, static_val<0> >(1, 0) + TensorUInt128<static_val<0>, static_val<1> >(1));
       uint64_t actual = static_cast<uint64_t>(result);
-      VERIFY_EQUAL(actual, expected);
+      VERIFY_IS_EQUAL(actual, expected);
     }
   }
 }