diff --git a/fit/function.h b/fit/function.h
index 80b1f55..0c5ced4 100644
--- a/fit/function.h
+++ b/fit/function.h
@@ -35,12 +35,8 @@
 #define FIT_CONST_FOLD(x) (__builtin_constant_p(x) ? (x) : (x))
 
 #ifndef FIT_NO_UNIQUE_STATIC_FUNCTION_ADDR
-#if defined(__GNUC__) && !defined (__clang__) && __GNUC__ == 4 && __GNUC_MINOR__ < 7
-#define FIT_NO_UNIQUE_STATIC_FUNCTION_ADDR 1
-#else
 #define FIT_NO_UNIQUE_STATIC_FUNCTION_ADDR 0
 #endif
-#endif
 
 namespace fit {
 
@@ -50,7 +46,7 @@ namespace detail {
 template<class T>
 struct static_const
 {
-    static constexpr T value {};
+    static constexpr T value = T();
 };
 
 template<class T>
@@ -122,16 +118,20 @@ struct static_addr
 }}
 
 #if FIT_NO_UNIQUE_STATIC_FUNCTION_ADDR
-#define FIT_STATIC_CONST_REF
+#define FIT_DETAIL_STATIC_FUNCTION_AUTO FIT_STATIC_CONSTEXPR
 #else
-#define FIT_STATIC_CONST_REF &
+#if defined(__GNUC__) && !defined (__clang__) && __GNUC__ == 4 && __GNUC_MINOR__ < 7
+#define FIT_DETAIL_STATIC_FUNCTION_AUTO static auto&
+#else
+#define FIT_DETAIL_STATIC_FUNCTION_AUTO static constexpr auto&
+#endif
 #endif
 
 #define FIT_DETAIL_MAKE_STATIC fit::detail::static_function_wrapper_factor() += true ? nullptr : fit::detail::static_addr()
 #define FIT_DETAIL_MAKE_REVEAL_STATIC(T) fit::detail::reveal_static_function_wrapper_factor<T>() += true ? nullptr : fit::detail::static_addr()
 #define FIT_STATIC_FUNCTION(name) \
 struct fit_private_static_function_ ## name {}; \
-static constexpr auto FIT_STATIC_CONST_REF name = FIT_DETAIL_MAKE_REVEAL_STATIC(fit_private_static_function_ ## name)
+FIT_DETAIL_STATIC_FUNCTION_AUTO name = FIT_DETAIL_MAKE_REVEAL_STATIC(fit_private_static_function_ ## name)
 
 
 #endif
diff --git a/test/test.h b/test/test.h
index 74a082d..5ec6a30 100644
--- a/test/test.h
+++ b/test/test.h
@@ -39,12 +39,8 @@ struct name \
 static fit::test::auto_register FIT_PP_CAT(name, _register) = fit::test::auto_register(name()); \
 void name::operator()() const
 
-
 template<class T>
-constexpr bool is_empty(const T&)
-{
-    return std::is_empty<T>::value;
-}
+T bare(const T&);
 
 }}
 
@@ -65,7 +61,7 @@ constexpr bool is_empty(const T&)
 #else
 #define STATIC_ASSERT_NOT_DEFAULT_CONSTRUCTIBLE(T) static_assert(!std::is_default_constructible<T>::value, "Default constructible")
 #endif
-#define STATIC_ASSERT_EMPTY(x) static_assert(fit::test::is_empty(x), "Not empty");
+#define STATIC_ASSERT_EMPTY(x) static_assert(std::is_empty<decltype(fit::test::bare(x))>::value, "Not empty");
 
 
 #define FIT_TEST_CASE() FIT_DETAIL_TEST_CASE(FIT_PP_CAT(test_, __LINE__))