diff --git a/include/gp-bnb/partition.hpp b/include/gp-bnb/partition.hpp
index b2e2cb34f267022f41d51c960a7bd4f636aadf10..bea434abbe11e275bceb8b5c63313c3325dfa620 100644
--- a/include/gp-bnb/partition.hpp
+++ b/include/gp-bnb/partition.hpp
@@ -21,7 +21,7 @@ public:
      *  @param  Subgraph A, B or none
      *  @return Number of vertices of sg
      */
-    unsigned int num_vertices(subgraph sg);
+    unsigned int num_vertices_of(subgraph sg);
     
     /** @brief  Assigns a vertex to a subgraph
      *  @param  Vertex Id