diff --git a/src/libraries/turtle/check.hpp b/src/libraries/turtle/check.hpp
index 0314036..0299708 100644
--- a/src/libraries/turtle/check.hpp
+++ b/src/libraries/turtle/check.hpp
@@ -9,13 +9,20 @@
 #ifndef MOCK_CHECK_HPP_INCLUDED
 #define MOCK_CHECK_HPP_INCLUDED
 
+#include "config.hpp"
 #include "is_functor.hpp"
 #include "constraints.hpp"
 #include "operators.hpp"
 #include "format.hpp"
-#include <boost/function.hpp>
 #include <boost/utility/enable_if.hpp>
 #include <boost/concept_check.hpp>
+#ifdef MOCK_USE_BOOST_BIND
+#include <boost/bind.hpp>
+#else
+#include <boost/spirit/home/phoenix/bind.hpp>
+#include <boost/spirit/home/phoenix/core/argument.hpp>
+#endif
+#include <boost/function.hpp>
 #include <stdexcept>
 #include <ostream>
 
@@ -30,8 +37,8 @@ namespace detail
         BOOST_CONCEPT_USAGE( FunctorCompatible )
         {
             boost::require_boolean_expr(
-                // if an error is generated by the line below it means an argument
-                // passed to 'with' was of the wrong type.
+                // if an error is generated by the line below it means
+                // an argument passed to 'with' was of the wrong type.
                 functor_accepts( actual_argument_type )
             );
         }
@@ -48,8 +55,8 @@ namespace detail
         BOOST_CONCEPT_USAGE( EqualityComparable )
         {
             boost::require_boolean_expr(
-                // if an error is generated by the line below it means an argument
-                // passed to 'with' was of the wrong type.
+                // if an error is generated by the line below it means
+                // an argument passed to 'with' was of the wrong type.
                 actual_argument_type == expected_argument_type
             );
         }
@@ -59,6 +66,28 @@ namespace detail
         Actual actual_argument_type;
     };
 
+    template< typename T >
+    void log( std::ostream& s, const T& t )
+    {
+        s << mock::format( t );
+    }
+
+#ifdef MOCK_USE_BOOST_BIND
+    template< typename T >
+    boost::function< void( std::ostream& ) > lazy_format( T t )
+    {
+        return boost::bind( &log< T >, _1, t );
+    }
+#else
+    template< typename T >
+    boost::function< void( std::ostream& ) > lazy_format( T t )
+    {
+        return boost::phoenix::bind(
+            &log< T >,
+            boost::phoenix::arg_names::_1, t );
+    }
+#endif
+
     template< typename Actual >
     class check
     {
@@ -68,7 +97,7 @@ namespace detail
             BOOST_DEDUCED_TYPENAME boost::enable_if<
                     BOOST_DEDUCED_TYPENAME detail::is_functor< Functor >
             >::type* = 0 )
-            : desc_( mock::format( f ) )
+            : desc_( lazy_format( f ) )
         {
             BOOST_CONCEPT_ASSERT(( FunctorCompatible< Functor, Actual > ));
             f_ = f;
@@ -80,19 +109,19 @@ namespace detail
             BOOST_DEDUCED_TYPENAME boost::disable_if<
                     BOOST_DEDUCED_TYPENAME detail::is_functor< Expected >
             >::type* = 0 )
-            : desc_( mock::format( expected ) )
+            : desc_( lazy_format( expected ) )
         {
             BOOST_CONCEPT_ASSERT(( EqualityComparable< Expected, Actual > ));
             f_ = mock::equal( expected ).f_;
             if( ! f_ )
                 std::invalid_argument( "invalid constraint" );
         }
-        template< typename Functor >
-        explicit check( const constraint< Functor >& ph )
-            : desc_( mock::format( ph.f_ ) )
+        template< typename Constraint >
+        explicit check( const constraint< Constraint >& c )
+            : desc_( lazy_format( c.f_ ) )
         {
-            BOOST_CONCEPT_ASSERT(( FunctorCompatible< Functor, Actual > ));
-            f_ = ph.f_;
+            BOOST_CONCEPT_ASSERT(( FunctorCompatible< Constraint, Actual > ));
+            f_ = c.f_;
             if( ! f_ )
                 std::invalid_argument( "invalid constraint" );
         }
@@ -104,12 +133,13 @@ namespace detail
 
         friend std::ostream& operator<<( std::ostream& s, const check& c )
         {
-            return s << c.desc_;
+            c.desc_( s );
+            return s;
         }
 
     private:
         boost::function< bool( Actual ) > f_;
-        std::string desc_;
+        boost::function< void( std::ostream& ) > desc_;
     };
 }
 }