diff --git a/include/turtle/config.hpp b/include/turtle/config.hpp
index 54000f6e..451d61ad 100644
--- a/include/turtle/config.hpp
+++ b/include/turtle/config.hpp
@@ -82,4 +82,10 @@
 #   endif
 #endif
 
+#if defined(MOCK_RVALUE_REFERENCES) && defined(MOCK_THREAD_SAFE)
+#   ifndef MOCK_NO_ASYNC
+#       define MOCK_ASYNC
+#   endif
+#endif
+
 #endif // MOCK_CONFIG_HPP_INCLUDED
diff --git a/include/turtle/detail/action.hpp b/include/turtle/detail/action.hpp
index db98aad0..0dabb5d3 100644
--- a/include/turtle/detail/action.hpp
+++ b/include/turtle/detail/action.hpp
@@ -127,7 +127,7 @@ namespace detail
             value_imp( BOOST_RV_REF( value_type ) t )
                 : t_( boost::move( t ) )
             {}
-            value_imp( const T& t )
+            value_imp( const typename boost::remove_reference<T>::type & t )
                 : t_( t )
             {}
             template< typename Y >
@@ -150,10 +150,10 @@ namespace detail
             return static_cast< value_imp< T >& >( *v_ ).t_;
         }
         template< typename T >
-        Result& store( T* t )
+        typename boost::remove_reference<Result>::type & store( T* t )
         {
             v_.reset( new value_imp< Result >( t ) );
-            return static_cast< value_imp< Result >& >( *v_ ).t_;
+            return static_cast< value_imp< typename boost::remove_reference< Result >::type >& >( *v_ ).t_;
         }
 
         boost::shared_ptr< value > v_;
diff --git a/include/turtle/detail/expectation_template.hpp b/include/turtle/detail/expectation_template.hpp
index a4f14a06..d1c8761e 100644
--- a/include/turtle/detail/expectation_template.hpp
+++ b/include/turtle/detail/expectation_template.hpp
@@ -7,6 +7,7 @@
 // http://www.boost.org/LICENSE_1_0.txt)
 
 #include "matcher_base_template.hpp"
+#include <boost/atomic.hpp>
 
 #define MOCK_EXPECTATION_INITIALIZE(z, n, d) \
     BOOST_PP_COMMA_IF(n) c##n##_( c##n )
@@ -133,7 +134,10 @@ namespace detail
                 > () )
             , file_( "unknown location" )
             , line_( 0 )
-        {}
+#if defined(MOCK_ASYNC)
+            , blocked(false)
+#endif
+        { }
         expectation( const char* file, int line )
             : invocation_( boost::make_shared< unlimited >() )
             , matcher_(
@@ -144,8 +148,32 @@ namespace detail
                 > () )
             , file_( file )
             , line_( line )
+#if defined(MOCK_ASYNC)
+            , blocked(false)
+#endif
+        { }
+
+        expectation(BOOST_RV_REF(expectation) e)
+            : invocation_ ( e.invocation_)
+            , matcher_(e.matcher_)
+            , file_(e.file_)
+            , line_(e.line_)
+#if defined(MOCK_ASYNC)
+            , blocked(false)
+#endif
         {}
 
+        expectation &operator=(BOOST_RV_REF(expectation) e)
+        {
+            invocation_ = e.invocation_;
+             matcher_ =e.matcher_;
+             file_ = e.file_;
+             line_ = e.line_;
+#if defined(MOCK_ASYNC)
+            blocked.store(false, boost::memory_order_release);
+#endif
+        }
+
         ~expectation()
         {
             for( sequences_cit it = sequences_.begin();
@@ -185,7 +213,15 @@ namespace detail
         }
 #endif
 #endif
-
+#if defined(MOCK_ASYNC)
+        template < typename duration>
+        expectation &async(const duration timeout)
+        {
+            timeout_ = timeout;
+            blocked.store(false,boost::memory_order_release);
+            return *this;
+        }
+#endif
         void add( sequence& s )
         {
             s.impl_->add( this );
@@ -196,16 +232,41 @@ namespace detail
         {
             return invocation_->verify();
         }
-
+#if defined(MOCK_ASYNC)
+        bool verify(const boost::shared_ptr< condition_variable> &cv, lock &lk) const
+        {
+            if (timeout_)
+            {
+                while (!invocation_->verify())
+                {
+                    if (MOCK_THREAD_NAMESPACE::cv_status::timeout == cv->wait_for(lk.get_unique_lock(), *timeout_))
+                    {
+                        blocked.store(true, boost::memory_order_release);
+                        return false;
+                    }
+                }
+            }
+            return invocation_->verify();
+        }
+#endif
         bool is_valid(
             BOOST_PP_ENUM_BINARY_PARAMS(MOCK_NUM_ARGS, T, a) ) const
         {
+#if defined(MOCK_ASYNC)
+            return !blocked.load(boost::memory_order_acquire) && !invocation_->exhausted()
+                && (*matcher_)( BOOST_PP_ENUM_PARAMS(MOCK_NUM_ARGS, a) );
+#else
             return !invocation_->exhausted()
                 && (*matcher_)( BOOST_PP_ENUM_PARAMS(MOCK_NUM_ARGS, a) );
+#endif
         }
 
         bool invoke() const
         {
+#if defined(MOCK_ASYNC)
+            if (blocked.load(boost::memory_order_acquire))
+                return false;
+#endif
             for( sequences_cit it = sequences_.begin();
                 it != sequences_.end(); ++it )
                 if( ! (*it)->is_valid( this ) )
@@ -252,6 +313,10 @@ namespace detail
         sequences_type sequences_;
         const char* file_;
         int line_;
+#if defined(MOCK_ASYNC)
+        boost::optional<nanoseconds> timeout_;
+        mutable boost::atomic<bool> blocked;
+#endif
     };
 }
 } // mock
diff --git a/include/turtle/detail/function.hpp b/include/turtle/detail/function.hpp
index 4a482204..19a016c9 100644
--- a/include/turtle/detail/function.hpp
+++ b/include/turtle/detail/function.hpp
@@ -49,6 +49,10 @@ namespace detail
             : e_( &e )
         {}
 
+        wrapper_base( BOOST_RV_REF(wrapper_base) w )
+            : e_( w.e_ )
+        {}
+
         template< typename T >
         void returns( T t )
         {
@@ -64,6 +68,11 @@ namespace detail
             : e_( &e )
         {}
 
+        wrapper_base( BOOST_RV_REF(wrapper_base) w )
+            : e_( w.e_ )
+        {}
+
+
         E* e_;
     };
     template< typename R, typename E >
@@ -73,6 +82,10 @@ namespace detail
             : e_( &e )
         {}
 
+        wrapper_base( BOOST_RV_REF(wrapper_base) w )
+            : e_( w.e_ )
+        {}
+
         void returns( R* r )
         {
             e_->returns( r );
diff --git a/include/turtle/detail/function_impl_template.hpp b/include/turtle/detail/function_impl_template.hpp
index 32f04b3b..a8fa1e2f 100644
--- a/include/turtle/detail/function_impl_template.hpp
+++ b/include/turtle/detail/function_impl_template.hpp
@@ -7,6 +7,9 @@
 // http://www.boost.org/LICENSE_1_0.txt)
 
 #include "expectation_template.hpp"
+#include <boost/move/utility.hpp>
+#include <boost/atomic.hpp>
+#include <iostream>
 
 #ifndef MOCK_ERROR_POLICY
 #   error no error policy has been set
@@ -44,20 +47,30 @@ namespace detail
             : context_( 0 )
             , valid_( true )
             , mutex_( boost::make_shared< mutex >() )
+#if defined(MOCK_ASYNC)
+            , cv_( boost::make_shared< condition_variable>() )
+#endif
         {}
         virtual ~function_impl()
         {
-            if( valid_ && ! std::uncaught_exception() )
-                for( expectations_cit it = expectations_.begin();
-                    it != expectations_.end(); ++it )
-                    if( ! it->verify() )
-                        error_type::fail( "untriggered expectation",
-                            boost::unit_test::lazy_ostream::instance()
-                                << lazy_context( this )
-                                << lazy_expectations( this ),
-                            it->file(), it->line() );
-            if( context_ )
-                context_->remove( *this );
+            if (valid_ && !std::uncaught_exception()){
+                lock _(mutex_);
+                for (expectations_cit it = expectations_.begin();
+                    it != expectations_.end(); ++it)
+#if defined(MOCK_ASYNC)
+                    if (!it->verify(cv_, _))
+#else
+                    if (!it->verify())
+#endif
+                        error_type::fail("untriggered expectation",
+                        boost::unit_test::lazy_ostream::instance()
+                        << lazy_context(this)
+                        << lazy_expectations(this),
+                        it->file(), it->line());
+            }
+            context *c = context_.load(boost::memory_order_acquire);
+            if (c)
+                c->remove( *this );
         }
 
         virtual bool verify() const
@@ -65,7 +78,11 @@ namespace detail
             lock _( mutex_ );
             for( expectations_cit it = expectations_.begin();
                 it != expectations_.end(); ++it )
+#if defined(MOCK_ASYNC)
+                if( ! it->verify(cv_,_) )
+#else
                 if( ! it->verify() )
+#endif
                 {
                     valid_ = false;
                     error_type::fail( "verification failed",
@@ -93,40 +110,52 @@ namespace detail
 
         struct wrapper : wrapper_base< R, expectation_type >
         {
+            private:
+                BOOST_MOVABLE_BUT_NOT_COPYABLE(wrapper);
+
+            public:
+
             wrapper( const boost::shared_ptr< mutex >& m, expectation_type& e )
                 : wrapper_base< R, expectation_type >( e )
                 , lock_( m )
             {}
 
-            wrapper once()
+            wrapper( BOOST_RV_REF(wrapper) w)
+                : wrapper_base< R, expectation_type > (*w.e_)
+                , lock_( boost::move(w.lock_) )
+            {
+
+            }
+
+            wrapper &once()
             {
                 this->e_->invoke( boost::make_shared< detail::once >() );
                 return *this;
             }
-            wrapper never()
+            wrapper &never()
             {
                 this->e_->invoke( boost::make_shared< detail::never >() );
                 return *this;
             }
-            wrapper exactly( std::size_t count )
+            wrapper &exactly( std::size_t count )
             {
                 this->e_->invoke(
                     boost::make_shared< detail::exactly >( count ) );
                 return *this;
             }
-            wrapper at_least( std::size_t min )
+            wrapper &at_least( std::size_t min )
             {
                 this->e_->invoke(
                     boost::make_shared< detail::at_least >( min ) );
                 return *this;
             }
-            wrapper at_most( std::size_t max )
+            wrapper &at_most( std::size_t max )
             {
                 this->e_->invoke(
                     boost::make_shared< detail::at_most >( max ) );
                 return *this;
             }
-            wrapper between( std::size_t min, std::size_t max )
+            wrapper &between( std::size_t min, std::size_t max )
             {
                 this->e_->invoke(
                     boost::make_shared< detail::between >( min, max ) );
@@ -137,7 +166,7 @@ namespace detail
             template<
                 BOOST_PP_ENUM_PARAMS(MOCK_NUM_ARGS, typename Constraint_)
             >
-            wrapper with(
+            wrapper &with(
                 BOOST_PP_ENUM_BINARY_PARAMS(MOCK_NUM_ARGS, Constraint_, c) )
             {
                 this->e_->with(
@@ -146,7 +175,7 @@ namespace detail
             }
 #if MOCK_NUM_ARGS > 1
             template< typename Constraint >
-            wrapper with( const Constraint& c )
+            wrapper &with( const Constraint& c )
             {
                 this->e_->with( c );
                 return *this;
@@ -158,7 +187,7 @@ namespace detail
     this->e_->add( s##n );
 
 #define MOCK_FUNCTION_IN(z, n, d) \
-    wrapper in( BOOST_PP_ENUM_PARAMS(n, sequence& s) ) \
+    wrapper &in( BOOST_PP_ENUM_PARAMS(n, sequence& s) ) \
     { \
         BOOST_PP_REPEAT(n, MOCK_FUNCTION_IN_ADD, _) \
         return *this; \
@@ -169,7 +198,13 @@ namespace detail
 
 #undef MOCK_FUNCTION_IN
 #undef MOCK_FUNCTION_IN_ADD
-
+#if defined(MOCK_ASYNC)
+            wrapper &async(const nanoseconds &timeout)
+            {
+                this->e_->async(timeout);
+                return *this;
+            }
+#endif
             template< typename TT >
             void calls( TT t )
             {
@@ -211,6 +246,19 @@ namespace detail
             BOOST_PP_ENUM_BINARY_PARAMS(MOCK_NUM_ARGS, T, t) ) const
         {
             lock _( mutex_ );
+#if defined(MOCK_ASYNC)
+            struct notify_cv_on_exit
+            {
+                notify_cv_on_exit(condition_variable &cv)
+                    : cv(cv){}
+                ~notify_cv_on_exit()
+                {
+                    cv.notify_one();
+                }
+                condition_variable &cv;
+            };
+            notify_cv_on_exit _cv(*cv_);
+#endif
             valid_ = false;
             for( expectations_cit it = expectations_.begin();
                 it != expectations_.end(); ++it )
@@ -246,11 +294,9 @@ namespace detail
             boost::optional< type_name > type,
             boost::unit_test::const_string name )
         {
-            lock _( mutex_ );
-            if( ! context_ )
+            if (!context_.exchange(&c,boost::memory_order_release))
                 c.add( *this );
             c.add( p, *this, instance, type, name );
-            context_ = &c;
         }
 
         friend std::ostream& operator<<(
@@ -268,8 +314,10 @@ namespace detail
             friend std::ostream& operator<<(
                 std::ostream& s, const lazy_context& c )
             {
-                if( c.impl_->context_ )
-                    c.impl_->context_->serialize( s, *c.impl_ );
+
+                context *pContext = c.impl_->context_.load(boost::memory_order_acquire);
+                if( pContext )
+                    pContext->serialize( s, *c.impl_ );
                 else
                     s << '?';
                 return s;
@@ -297,9 +345,12 @@ namespace detail
         typedef typename expectations_type::const_iterator expectations_cit;
 
         expectations_type expectations_;
-        context* context_;
+        boost::atomic<context*> context_;
         mutable bool valid_;
         const boost::shared_ptr< mutex > mutex_;
+#if defined(MOCK_ASYNC)
+        const boost::shared_ptr<condition_variable> cv_;
+#endif
     };
 }
 } // mock
diff --git a/include/turtle/detail/mutex.hpp b/include/turtle/detail/mutex.hpp
index 4837c6cb..1c4deb65 100644
--- a/include/turtle/detail/mutex.hpp
+++ b/include/turtle/detail/mutex.hpp
@@ -17,45 +17,77 @@
 
 #ifdef MOCK_HDR_MUTEX
 #include <mutex>
+#include <condition_variable>
+#include <chrono>
 #else
 #include <boost/thread/recursive_mutex.hpp>
 #include <boost/thread/lock_guard.hpp>
+#include <boost/thread/condition_variable.hpp>
+#include <boost/chrono.hpp>
+#endif
+
+#ifdef MOCK_HDR_MUTEX
+#define MOCK_THREAD_NAMESPACE std
+#else
+#define MOCK_THREAD_NAMESPACE boost
 #endif
 
 namespace mock
 {
 namespace detail
 {
-#ifdef MOCK_HDR_MUTEX
-    typedef std::recursive_mutex mutex;
-    typedef std::lock_guard< mutex > scoped_lock;
-#else
-    typedef boost::recursive_mutex mutex;
-    typedef boost::lock_guard< mutex > scoped_lock;
-#endif
+    typedef MOCK_THREAD_NAMESPACE::recursive_mutex mutex;
+    typedef MOCK_THREAD_NAMESPACE::lock_guard< mutex > scoped_lock;
+    typedef MOCK_THREAD_NAMESPACE::condition_variable_any condition_variable;
+    typedef MOCK_THREAD_NAMESPACE::chrono::nanoseconds nanoseconds;
+    typedef MOCK_THREAD_NAMESPACE::unique_lock<mutex> lock_base;
+
+#if defined(MOCK_ASYNC)
+    struct lock : public lock_base
+    {
+        lock(const boost::shared_ptr< detail::mutex > &m)
+            : lock_base (*m)
+            , m_(m)
+        {}
+
+        lock(BOOST_RV_REF(lock) l)
+            : lock_base(*l.m_)
+            , m_(l.m_)
+        {
+        }
+        ~lock()
+        {
+            unlock();
+        }
+        lock_base &get_unique_lock() { return *this; }
+
+        boost::shared_ptr< detail::mutex > m_;
+    };
+#else // MOCK_ASYNC
 
     struct lock
     {
-        lock( const boost::shared_ptr< mutex >& m )
-            : m_( m )
+        lock(const boost::shared_ptr< detail::mutex > &m)
+            : m_(m)
         {
             m_->lock();
         }
-        lock( const lock& rhs )
+
+        lock( const lock & rhs)
         {
-            m_.swap( rhs.m_ );
+            m_.swap(rhs.m_);
         }
         ~lock()
         {
-            if( m_ )
-                m_->unlock();
+            if(m_)
+              m_->unlock();
         }
-
-    private:
-        lock& operator=( const lock& rhs );
-
-        mutable boost::shared_ptr< mutex > m_;
+        private:
+            lock & operator=(const lock &rhs);
+            mutable boost::shared_ptr< detail::mutex > m_;
     };
+
+#endif // MOCK_ASYNC
 }
 } // mock
 
diff --git a/include/turtle/detail/object_impl.hpp b/include/turtle/detail/object_impl.hpp
index 6aa215f5..ba85adfd 100644
--- a/include/turtle/detail/object_impl.hpp
+++ b/include/turtle/detail/object_impl.hpp
@@ -31,6 +31,7 @@ namespace detail
     public:
         object_impl()
             : mutex_( boost::make_shared< mutex >() )
+            , children_mutex_( boost::make_shared< mutex >() )
         {}
 
         virtual void add( const void* /*p*/, verifiable& v,
@@ -38,7 +39,7 @@ namespace detail
             boost::optional< type_name > type,
             boost::unit_test::const_string name )
         {
-            lock _( mutex_ );
+            lock _( children_mutex_ );
             if( children_.empty() )
                 detail::root.add( *this );
             children_[ &v ].update( parent_, instance, type, name );
@@ -50,16 +51,21 @@ namespace detail
         }
         virtual void remove( verifiable& v )
         {
-            lock _( mutex_ );
-            group_.remove( v );
-            children_.erase( &v );
-            if( children_.empty() )
-                detail::root.remove( *this );
+            {
+                lock _(mutex_);
+                group_.remove(v);
+            }
+            {
+                lock _( children_mutex_ );
+                children_.erase(&v);
+                if (children_.empty())
+                    detail::root.remove(*this);
+            }
         }
 
         virtual void serialize( std::ostream& s, const verifiable& v ) const
         {
-            lock _( mutex_ );
+            lock _( children_mutex_ );
             children_cit it = children_.find( &v );
             if( it != children_.end() )
                 s << it->second;
@@ -72,6 +78,7 @@ namespace detail
             lock _( mutex_ );
             return group_.verify();
         }
+
         virtual void reset()
         {
             lock _( mutex_ );
@@ -87,6 +94,7 @@ namespace detail
         parent parent_;
         children_t children_;
         const boost::shared_ptr< mutex > mutex_;
+        const boost::shared_ptr< mutex > children_mutex_;
     };
 }
 } // mock
diff --git a/test/test_async.cpp b/test/test_async.cpp
new file mode 100644
index 00000000..8e314be3
--- /dev/null
+++ b/test/test_async.cpp
@@ -0,0 +1,93 @@
+// http://turtle.sourceforge.net
+//
+// Copyright Mathieu Champlon 2009
+//
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+
+#include "mock_error.hpp"
+#include <turtle/mock.hpp>
+#include <boost/test/auto_unit_test.hpp>
+#include <boost/lexical_cast.hpp>
+
+#if defined(MOCK_HDR_MUTEX)
+#include <thread>
+#else
+#include <boost/thread.hpp>
+#endif
+
+namespace
+{
+    MOCK_CLASS( mock_class )
+    {
+        MOCK_METHOD_EXT( my_method, 1, void( const std::string& ), my_tag )
+        MOCK_METHOD_EXT( my_method2, 1, void( const std::string& ), my_tag2 )
+    };
+}
+
+
+BOOST_FIXTURE_TEST_CASE( mock_object_asynchonous_call_expectation, mock_error_fixture )
+{
+#if defined(MOCK_ASYNC)
+    const mock_class m{};
+    MOCK_EXPECT( m.my_tag ).async(MOCK_THREAD_NAMESPACE::chrono::milliseconds(50)).once().with( "some parameter" );
+    MOCK_THREAD_NAMESPACE::thread context([&](){
+        MOCK_THREAD_NAMESPACE::this_thread::sleep_for(MOCK_THREAD_NAMESPACE::chrono::milliseconds(10));
+        m.my_method("some parameter");
+    });
+    mock::verify();
+    CHECK_CALLS( 1 );
+    context.join();
+#endif
+
+}
+
+BOOST_FIXTURE_TEST_CASE( mock_object_asynchonous_call_expectation_in_sequence, mock_error_fixture )
+{
+#if defined(MOCK_ASYNC)
+    const mock_class m{};
+    mock::sequence s;
+    MOCK_EXPECT( m.my_tag ).async(MOCK_THREAD_NAMESPACE::chrono::milliseconds(50)).once().in(s).with( "some parameter" );
+    MOCK_EXPECT( m.my_tag ).async(MOCK_THREAD_NAMESPACE::chrono::milliseconds(150)).once().in(s).with( "some parameter2" );
+    MOCK_THREAD_NAMESPACE::thread context([&](){
+        MOCK_THREAD_NAMESPACE::this_thread::sleep_for(MOCK_THREAD_NAMESPACE::chrono::milliseconds(10));
+        m.my_method("some parameter");
+        MOCK_THREAD_NAMESPACE::this_thread::sleep_for(MOCK_THREAD_NAMESPACE::chrono::milliseconds(20));
+        m.my_method("some parameter2");
+    });
+    mock::verify();
+    CHECK_CALLS( 2 );
+    context.join();
+#endif
+
+}
+
+
+
+BOOST_AUTO_TEST_CASE( mock_object_asynchonous_call_expectation_fails )
+{
+#if defined(MOCK_ASYNC)
+    mock::reset();
+    mock_error_data.reset();
+    const mock_class m{};
+    bool unexpected_call_received = false;
+    MOCK_EXPECT( m.my_tag ).async(MOCK_THREAD_NAMESPACE::chrono::milliseconds(50)).once().with( "some parameter" );
+    MOCK_THREAD_NAMESPACE::thread context([&](){
+        MOCK_THREAD_NAMESPACE::this_thread::sleep_for(MOCK_THREAD_NAMESPACE::chrono::milliseconds(100));
+        try{
+            m.my_method("some parameter");
+        }
+        catch (std::exception &)
+        {
+            unexpected_call_received = true;
+        }
+    });
+    CHECK_ERROR(
+        BOOST_CHECK(!mock::verify()),
+        "verification failed", 0, "m.mock_class::my_tag\n. once().with( \"some parameter\" )");
+    context.join();
+    BOOST_CHECK(unexpected_call_received == true);
+#endif
+}
diff --git a/test/test_mock.cpp b/test/test_mock.cpp
index 7a41f6f2..dbb8658c 100644
--- a/test/test_mock.cpp
+++ b/test/test_mock.cpp
@@ -367,7 +367,7 @@ namespace
 
     MOCK_BASE_CLASS( variadic, base )
     {
-        MOCK_METHOD( m1, 0 )
+        MOCK_METHOD( m1, 0, void() )
         MOCK_METHOD( m2, 0, void() )
         MOCK_METHOD( m3, 0, void(), m3 )
         MOCK_CONST_METHOD( m4, 0, void() )