diff --git a/include/boost/graph/graph_concepts.hpp b/include/boost/graph/graph_concepts.hpp
index 3dfbc506..a2688bbf 100644
--- a/include/boost/graph/graph_concepts.hpp
+++ b/include/boost/graph/graph_concepts.hpp
@@ -395,15 +395,14 @@ namespace boost {
   struct LvaluePropertyGraphConcept
   {
     typedef typename property_map<G, Property>::type Map;
+    typedef typename property_map<G, Property>::const_type const_Map;
     void constraints() {
       function_requires< ReadablePropertyGraphConcept<G, X, Property> >();
-      function_requires< LvaluePropertyMapConcept<Map, X> >();
+      function_requires< LvaluePropertyMapConcept<const_Map, X> >();
       function_requires< Mutable_LvaluePropertyMapConcept<Map, X> >();
 
-      Map pmap = get(Property(), g);
       pval = get(Property(), g, x);
       put(Property(), g, x, pval);
-      ignore_unused_variable_warning(pmap);
     }
     G g;
     X x;