diff --git a/BGL/include/CGAL/boost/graph/graph_traits_PolyMesh_ArrayKernelT.h b/BGL/include/CGAL/boost/graph/graph_traits_PolyMesh_ArrayKernelT.h
index ddc3f15289b..997e101d9e5 100644
--- a/BGL/include/CGAL/boost/graph/graph_traits_PolyMesh_ArrayKernelT.h
+++ b/BGL/include/CGAL/boost/graph/graph_traits_PolyMesh_ArrayKernelT.h
@@ -60,6 +60,11 @@ public:
     }
   }
 
+  bool operator<(const OMesh_edge& other) const
+  { 
+    return this->idx() < other.idx();
+  }
+
   bool
   operator!=(const OMesh_edge& other) { return !(*this == other); }