diff --git a/src/graph/edge.cc b/src/graph/edge.cc
index a08134704f3a917f6d92ef82917a71afab733e18..f08aa4bc8442e088fb8cd3f7ef285631bf65798b 100644
--- a/src/graph/edge.cc
+++ b/src/graph/edge.cc
@@ -124,6 +124,7 @@ namespace hpp {
         }
         if (securityMargins_(row, col) != margin) {
           securityMargins_(row, col) = margin;
+          securityMargins_(col, row) = margin;
           isInit_ = false;
         }
       }