diff --git a/include/boost/optional/detail/optional_trivially_copyable_base.hpp b/include/boost/optional/detail/optional_trivially_copyable_base.hpp
index 0734f62..5a37eac 100644
--- a/include/boost/optional/detail/optional_trivially_copyable_base.hpp
+++ b/include/boost/optional/detail/optional_trivially_copyable_base.hpp
@@ -30,7 +30,7 @@ class tc_optional_base : public optional_tag
       :
       m_initialized(false) {}
 
-    tc_optional_base ( argument_type val )
+    tc_optional_base ( init_value_tag, argument_type val )
       :
       m_initialized(true), m_storage(val) {}
 
diff --git a/include/boost/optional/optional.hpp b/include/boost/optional/optional.hpp
index 104bca4..90acd40 100644
--- a/include/boost/optional/optional.hpp
+++ b/include/boost/optional/optional.hpp
@@ -107,7 +107,9 @@ using optional_ns::in_place_init_if;
 
 namespace optional_detail {
 
-struct optional_tag {} ;
+struct init_value_tag {};
+
+struct optional_tag {};
 
 
 template<class T>
@@ -147,7 +149,7 @@ class optional_base : public optional_tag
 
     // Creates an optional<T> initialized with 'val'.
     // Can throw if T::T(T const&) does
-    optional_base ( argument_type val )
+    optional_base ( init_value_tag, argument_type val )
       :
       m_initialized(false)
     {
@@ -157,7 +159,7 @@ class optional_base : public optional_tag
 #ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // move-construct an optional<T> initialized from an rvalue-ref to 'val'.
     // Can throw if T::T(T&&) does
-    optional_base ( rval_reference_type val )
+    optional_base ( init_value_tag, rval_reference_type val )
       :
       m_initialized(false)
     {
@@ -870,12 +872,12 @@ class optional
 
     // Creates an optional<T> initialized with 'val'.
     // Can throw if T::T(T const&) does
-    optional ( argument_type val ) : base(val) {}
+    optional ( argument_type val ) : base(optional_detail::init_value_tag(), val) {}
 
 #ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // Creates an optional<T> initialized with 'move(val)'.
     // Can throw if T::T(T &&) does
-    optional ( rval_reference_type val ) : base( boost::forward<T>(val) )
+    optional ( rval_reference_type val ) : base(optional_detail::init_value_tag(), boost::forward<T>(val))
       {}
 #endif