diff --git a/libs/librrgraph/src/base/rr_graph_storage.cpp b/libs/librrgraph/src/base/rr_graph_storage.cpp
index a9568810e3..405139712b 100644
--- a/libs/librrgraph/src/base/rr_graph_storage.cpp
+++ b/libs/librrgraph/src/base/rr_graph_storage.cpp
@@ -235,6 +235,12 @@ class edge_sort_iterator {
         return lhs.swapper_.idx_ <= rhs.swapper_.idx_;
     }
 
+    const t_rr_edge_info operator[] (ssize_t n) const {
+      edge_sort_iterator ret = *this;
+      ret.swapper_.idx_ += n;
+      return ret.swapper_;
+    }
+
     RREdgeId edge() const {
         return RREdgeId(swapper_.idx_);
     }