diff --git a/src/configwrapper.h b/src/configwrapper.h
index 87bb7e5..c22313d 100644
--- a/src/configwrapper.h
+++ b/src/configwrapper.h
@@ -21,9 +21,6 @@ class ConfigWrapper : public ConfigWrapperInterface
     CPP_DISABLE_COPY_MOVE(ConfigWrapper)
 
 public:
-    using DefaultValueCallbackRef = T(&)();
-    using DefaultValueCallbackPtr = T(*)();
-
     using value_t = typename std::conditional<std::is_same<T, std::string>::value, const T &, T>::type;
     using ConstraintCallback = ConfigConstraintReturnType(*)(value_t);