diff --git a/include/boost/graph/is_kuratowski_subgraph.hpp b/include/boost/graph/is_kuratowski_subgraph.hpp
index 8791b4cf..668043ab 100644
--- a/include/boost/graph/is_kuratowski_subgraph.hpp
+++ b/include/boost/graph/is_kuratowski_subgraph.hpp
@@ -301,11 +301,11 @@ namespace boost
     
     if (target_graph == detail::tg_k_5)
       {
-        return isomorphism(K_5,contracted_graph);
+        return boost::isomorphism(K_5,contracted_graph);
       }
     else //target_graph == tg_k_3_3
       {
-        return isomorphism(K_3_3,contracted_graph);
+        return boost::isomorphism(K_3_3,contracted_graph);
       }