diff --git a/include/boost/graph/adjacency_list_io.hpp b/include/boost/graph/adjacency_list_io.hpp
index 4b8dc037..52342b08 100644
--- a/include/boost/graph/adjacency_list_io.hpp
+++ b/include/boost/graph/adjacency_list_io.hpp
@@ -178,7 +178,7 @@ struct PropertyPrinter<Graph, no_property>
   PropertyPrinter( Graph& ){}
 
   template<class Iterator>
-  PropertyPrinter& operator () ( std::ostream&, Iterator it ){ return *this; }
+  PropertyPrinter& operator () ( std::ostream&, Iterator){ return *this; }
 };
 
 // property printer