diff --git a/Geo/discreteDiskFace.h b/Geo/discreteDiskFace.h
index 3929f8f18b0b496d9ae17a0d344a520d57b6b199..23a01ebf4d2a2c1a021a5b2aa21cf52a1f17e95c 100644
--- a/Geo/discreteDiskFace.h
+++ b/Geo/discreteDiskFace.h
@@ -58,10 +58,11 @@ class triangulation {
   int idNum; // number of identification, for hashing purposes
 
   std::list<GEdge*> my_GEdges;
-  
+
   //methods
-  int genus(){
-    return ( -vert.size() + ed2tri.size() - tri.size() + 2 - bord.size() )/2;
+  int genus()
+  {
+    return ( ed2tri.size() - vert.size() - tri.size() + 2 - bord.size() )/2;
   }
 
   void assignVert()