diff --git a/rogueviz/graphs.cpp b/rogueviz/graphs.cpp
index 0a77f17a..c2b4001b 100644
--- a/rogueviz/graphs.cpp
+++ b/rogueviz/graphs.cpp
@@ -584,6 +584,7 @@ void draw_edge(const shiftmatrix &V, cell *c, edgeinfo *ei) {
 
   vertexdata& vd1 = vdata[ei->i];
   vertexdata& vd2 = vdata[ei->j];
+  if(!vd1.m || !vd2.m) return;
 
   int oi = ei->i, oj = ei->j;
   bool hilite = false;