diff --git a/test/test_cpp_int.cpp b/test/test_cpp_int.cpp
index d28b7a1b2..13c89199c 100644
--- a/test/test_cpp_int.cpp
+++ b/test/test_cpp_int.cpp
@@ -94,6 +94,8 @@ struct tester
    boost::multiprecision::double_limb_type large_ui;
    test_type                      a1, b1, c1, d1;
 
+   BOOST_MP_CXX14_CONSTEXPR test_type z = 0;
+
    void t1()
    {
       using namespace boost::multiprecision;