diff --git a/test/failed_test.cpp b/test/failed_test.cpp
index 67a317d..118d35f 100644
--- a/test/failed_test.cpp
+++ b/test/failed_test.cpp
@@ -13,6 +13,12 @@ using namespace boost::system;
 
 struct http_category_impl: public error_category
 {
+    // clang++ 3.8 and below: initialization of const object
+    // requires a user-provided default constructor
+    BOOST_SYSTEM_CONSTEXPR http_category_impl() BOOST_NOEXCEPT
+    {
+    }
+
     char const * name() const BOOST_NOEXCEPT
     {
         return "http";