diff --git a/include/boost/multiprecision/detail/ublas_interop.hpp b/include/boost/multiprecision/detail/ublas_interop.hpp
new file mode 100644
index 00000000..d1aae4dc
--- /dev/null
+++ b/include/boost/multiprecision/detail/ublas_interop.hpp
@@ -0,0 +1,65 @@
+///////////////////////////////////////////////////////////////////////////////
+//  Copyright 2013 John Maddock. Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_MP_UBLAS_HPP
+#define BOOST_MP_UBLAS_HPP
+
+namespace boost { namespace numeric { namespace ublas {
+
+template<class V>
+class sparse_vector_element;
+
+template <class V, class Backend, multiprecision::expression_template_option ExpressionTemplates>
+inline bool operator == (const sparse_vector_element<V>& a, const ::boost::multiprecision::number<Backend, ExpressionTemplates>& b)
+{
+   typedef typename sparse_vector_element<V>::const_reference ref_type;
+   return static_cast<ref_type>(a) == b;
+}
+
+template<class X, class Y>
+struct promote_traits;
+
+template <class Backend1, boost::multiprecision::expression_template_option ExpressionTemplates1, class Backend2, boost::multiprecision::expression_template_option ExpressionTemplates2>
+struct promote_traits<boost::multiprecision::number<Backend1, ExpressionTemplates1>, boost::multiprecision::number<Backend2, ExpressionTemplates2> >
+{
+   typedef boost::multiprecision::number<Backend1, ExpressionTemplates1> number1_t;
+   typedef boost::multiprecision::number<Backend2, ExpressionTemplates2> number2_t;
+   typedef typename mpl::if_c<
+      is_convertible<number1_t, number2_t>::value && !is_convertible<number2_t, number1_t>::value,
+      number2_t, number1_t
+   >::type promote_type;
+};
+
+template <class Backend1, boost::multiprecision::expression_template_option ExpressionTemplates1, class tag, class Arg1, class Arg2, class Arg3, class Arg4>
+struct promote_traits<boost::multiprecision::number<Backend1, ExpressionTemplates1>, boost::multiprecision::detail::expression<tag, Arg1, Arg2, Arg3, Arg4> >
+{
+   typedef boost::multiprecision::number<Backend1, ExpressionTemplates1> number1_t;
+   typedef boost::multiprecision::detail::expression<tag, Arg1, Arg2, Arg3, Arg4> expression_type;
+   typedef typename expression_type::result_type number2_t;
+   typedef typename promote_traits<number1_t, number2_t>::promote_type promote_type;
+};
+
+template <class tag, class Arg1, class Arg2, class Arg3, class Arg4, class Backend1, boost::multiprecision::expression_template_option ExpressionTemplates1>
+struct promote_traits<boost::multiprecision::detail::expression<tag, Arg1, Arg2, Arg3, Arg4>, boost::multiprecision::number<Backend1, ExpressionTemplates1> >
+{
+   typedef boost::multiprecision::number<Backend1, ExpressionTemplates1> number1_t;
+   typedef boost::multiprecision::detail::expression<tag, Arg1, Arg2, Arg3, Arg4> expression_type;
+   typedef typename expression_type::result_type number2_t;
+   typedef typename promote_traits<number1_t, number2_t>::promote_type promote_type;
+};
+
+template <class tag, class Arg1, class Arg2, class Arg3, class Arg4, class tagb, class Arg1b, class Arg2b, class Arg3b, class Arg4b>
+struct promote_traits<boost::multiprecision::detail::expression<tag, Arg1, Arg2, Arg3, Arg4>, boost::multiprecision::detail::expression<tagb, Arg1b, Arg2b, Arg3b, Arg4b> >
+{
+   typedef boost::multiprecision::detail::expression<tag, Arg1, Arg2, Arg3, Arg4> expression1_t;
+   typedef typename expression1_t::result_type number1_t;
+   typedef boost::multiprecision::detail::expression<tagb, Arg1b, Arg2b, Arg3b, Arg4b> expression2_t;
+   typedef typename expression2_t::result_type number2_t;
+};
+
+}}} // namespace
+
+#endif
+