diff --git a/src/meshTools/edgeMesh/extendedEdgeMesh/extendedEdgeMesh.C b/src/meshTools/edgeMesh/extendedEdgeMesh/extendedEdgeMesh.C
index 977cb457ca..24c13c3559 100644
--- a/src/meshTools/edgeMesh/extendedEdgeMesh/extendedEdgeMesh.C
+++ b/src/meshTools/edgeMesh/extendedEdgeMesh/extendedEdgeMesh.C
@@ -1277,13 +1277,15 @@ void Foam::extendedEdgeMesh::add(const extendedEdgeMesh& fem)
         );
     }
 
-    pointField newEdgeDirections(newEdgeI);
+    pointField newEdgeDirections
+    (
+        edgeDirections().size()
+      + fem.edgeDirections().size()
+    );
     newEdgeDirections.rmap(edgeDirections(), reverseEdgeMap);
     newEdgeDirections.rmap(fem.edgeDirections(), reverseFemEdgeMap);
 
 
-
-
     // Normals
     // ~~~~~~~