diff --git a/test/test_convert_from_cpp_int.cpp b/test/test_convert_from_cpp_int.cpp
new file mode 100644
index 00000000..1ab65d94
--- /dev/null
+++ b/test/test_convert_from_cpp_int.cpp
@@ -0,0 +1,220 @@
+///////////////////////////////////////////////////////////////
+//  Copyright 2012 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_
+
+#ifdef _MSC_VER
+#  define _SCL_SECURE_NO_WARNINGS
+#endif
+
+#include <boost/multiprecision/cpp_int.hpp>
+#include <boost/random/mersenne_twister.hpp>
+#include "test.hpp"
+
+#if defined(HAS_GMP)
+#include <boost/multiprecision/gmp.hpp>
+#endif
+#if defined(HAS_MPFR)
+#include <boost/multiprecision/mpfr.hpp>
+#endif
+#if defined(HAS_MPFI)
+#include <boost/multiprecision/mpfi.hpp>
+#endif
+#ifdef HAS_TOMMATH
+#include <boost/multiprecision/tommath.hpp>
+#endif
+#ifdef HAS_FLOAT128
+#include <boost/multiprecision/float128.hpp>
+#endif
+#include <boost/multiprecision/cpp_bin_float.hpp>
+#include <boost/multiprecision/cpp_dec_float.hpp>
+
+
+using namespace boost::multiprecision;
+
+template <class T>
+T generate_random(unsigned bits_wanted)
+{
+   static boost::random::mt19937 gen;
+   typedef boost::random::mt19937::result_type random_type;
+
+   T max_val;
+   unsigned digits;
+   if(std::numeric_limits<T>::is_bounded && (bits_wanted == (unsigned)std::numeric_limits<T>::digits))
+   {
+      max_val = (std::numeric_limits<T>::max)();
+      digits = std::numeric_limits<T>::digits;
+   }
+   else
+   {
+      max_val = T(1) << bits_wanted;
+      digits = bits_wanted;
+   }
+
+   unsigned bits_per_r_val = std::numeric_limits<random_type>::digits - 1;
+   while((random_type(1) << bits_per_r_val) > (gen.max)()) --bits_per_r_val;
+
+   unsigned terms_needed = digits / bits_per_r_val + 1;
+
+   T val = 0;
+   for(unsigned i = 0; i < terms_needed; ++i)
+   {
+      val *= (gen.max)();
+      val += gen();
+   }
+   val %= max_val;
+   return val;
+}
+
+template <class From, class To>
+void test_convert_neg_int(From from, const boost::mpl::true_&)
+{
+   from = -from;
+   To t3(from);
+   To t4 = from.template convert_to<To>();
+   BOOST_CHECK_EQUAL(from.str(), t3.str());
+   BOOST_CHECK_EQUAL(from.str(), t4.str());
+}
+template <class From, class To>
+void test_convert_neg_int(From const&, const boost::mpl::false_&)
+{
+}
+
+template <class From, class To>
+void test_convert_imp(boost::mpl::int_<number_kind_integer> const&, boost::mpl::int_<number_kind_integer> const&)
+{
+   int bits_wanted = (std::min)((std::min)(std::numeric_limits<From>::digits, std::numeric_limits<To>::digits), 2000);
+
+   for(unsigned i = 0; i < 100; ++i)
+   {
+      From from = generate_random<From>(bits_wanted);
+      To t1(from);
+      To t2 = from.template convert_to<To>();
+      BOOST_CHECK_EQUAL(from.str(), t1.str());
+      BOOST_CHECK_EQUAL(from.str(), t2.str());
+      test_convert_neg_int<From, To>(from, boost::mpl::bool_<std::numeric_limits<From>::is_signed && std::numeric_limits<To>::is_signed>());
+   }
+}
+
+template <class From, class To>
+void test_convert_neg_rat(From from, const boost::mpl::true_&)
+{
+   from = -from;
+   To t3(from);
+   To t4 = from.template convert_to<To>();
+   BOOST_CHECK_EQUAL(from.str(), numerator(t3).str());
+   BOOST_CHECK_EQUAL(from.str(), numerator(t4).str());
+}
+template <class From, class To>
+void test_convert_neg_rat(From const&, const boost::mpl::false_&)
+{
+}
+
+template <class From, class To>
+void test_convert_imp(boost::mpl::int_<number_kind_integer> const&, boost::mpl::int_<number_kind_rational> const&)
+{
+   int bits_wanted = (std::min)((std::min)(std::numeric_limits<From>::digits, std::numeric_limits<To>::digits), 2000);
+
+   for(unsigned i = 0; i < 100; ++i)
+   {
+      From from = generate_random<From>(bits_wanted);
+      To t1(from);
+      To t2 = from.template convert_to<To>();
+      BOOST_CHECK_EQUAL(from.str(), numerator(t1).str());
+      BOOST_CHECK_EQUAL(from.str(), numerator(t2).str());
+      test_convert_neg_rat<From, To>(from, boost::mpl::bool_<std::numeric_limits<From>::is_signed && std::numeric_limits<To>::is_signed>());
+   }
+}
+
+template <class From, class To>
+void test_convert_neg_float(From from, const boost::mpl::true_&)
+{
+   from = -from;
+   To t3(from);
+   To t4 = from.template convert_to<To>();
+   To check(from.str() + ".0");
+   BOOST_CHECK_EQUAL(t3, check);
+   BOOST_CHECK_EQUAL(t4, check);
+}
+template <class From, class To>
+void test_convert_neg_float(From const&, const boost::mpl::false_&)
+{
+}
+
+template <class From, class To>
+void test_convert_imp(boost::mpl::int_<number_kind_integer> const&, boost::mpl::int_<number_kind_floating_point> const&)
+{
+   int bits_wanted = (std::min)((std::min)(std::numeric_limits<From>::digits, std::numeric_limits<To>::digits), 2000);
+
+   for(unsigned i = 0; i < 100; ++i)
+   {
+      From from = generate_random<From>(bits_wanted);
+      To t1(from);
+      To t2 = from.template convert_to<To>();
+      To check(from.str() + ".0");
+      BOOST_CHECK_EQUAL(t1, check);
+      BOOST_CHECK_EQUAL(t2, check);
+      test_convert_neg_float<From, To>(from, boost::mpl::bool_<std::numeric_limits<From>::is_signed && std::numeric_limits<To>::is_signed>());
+   }
+}
+
+
+template <class From, class To>
+void test_convert()
+{
+   test_convert_imp<From, To>(number_category<From>::type(), number_category<To>::type());
+}
+
+
+int main()
+{
+   test_convert<cpp_int, int128_t>();
+   test_convert<int128_t, cpp_int>();
+
+   test_convert<cpp_int, cpp_rational>();
+   test_convert<int128_t, cpp_rational>();
+   test_convert<uint128_t, cpp_rational>();
+
+   test_convert<cpp_int, cpp_bin_float_50>();
+   test_convert<int128_t, cpp_bin_float_50>();
+   test_convert<uint128_t, cpp_bin_float_50>();
+
+   test_convert<cpp_int, cpp_dec_float_50>();
+   test_convert<int128_t, cpp_dec_float_50>();
+   test_convert<uint128_t, cpp_dec_float_50>();
+
+#if defined(HAS_GMP)
+   test_convert<cpp_int, mpz_int>();
+   test_convert<int128_t, mpz_int>();
+   test_convert<uint128_t, mpz_int>();
+
+   test_convert<cpp_int, mpq_rational>();
+   test_convert<int128_t, mpq_rational>();
+   test_convert<uint128_t, mpq_rational>();
+
+   test_convert<cpp_int, mpf_float_50>();
+   test_convert<int128_t, mpf_float_50>();
+   test_convert<uint128_t, mpf_float_50>();
+#endif
+#if defined(HAS_MPFR)
+   test_convert<cpp_int, mpfr_float_50>();
+   test_convert<int128_t, mpfr_float_50>();
+   test_convert<uint128_t, mpfr_float_50>();
+#endif
+#if defined(HAS_MPFI)
+   test_convert<cpp_int, mpfi_float_50>();
+   test_convert<int128_t, mpfi_float_50>();
+   test_convert<uint128_t, mpfi_float_50>();
+#endif
+#ifdef HAS_TOMMATH
+   test_convert<cpp_int, tom_int>();
+   test_convert<int128_t, tom_int>();
+   test_convert<uint128_t, tom_int>();
+
+   test_convert<cpp_int, tom_rational>();
+   test_convert<int128_t, tom_rational>();
+   test_convert<uint128_t, tom_rational>();
+#endif
+   return boost::report_errors();
+}
+