diff --git a/pcbnew/router/pns_diff_pair.cpp b/pcbnew/router/pns_diff_pair.cpp
index 0279e1bd9f..60889072fd 100644
--- a/pcbnew/router/pns_diff_pair.cpp
+++ b/pcbnew/router/pns_diff_pair.cpp
@@ -410,6 +410,10 @@ static VECTOR2I makeGapVector( VECTOR2I dir, int length )
 {
     int l = length / 2;
     VECTOR2I rv;
+
+    if( dir.EuclideanNorm() == 0 )
+        return dir;
+
     do
 	{
         rv = dir.Resize( l );