diff --git a/src/laybasic/laybasic/layFinder.cc b/src/laybasic/laybasic/layFinder.cc
index 313a480e0..e70ab6a06 100644
--- a/src/laybasic/laybasic/layFinder.cc
+++ b/src/laybasic/laybasic/layFinder.cc
@@ -479,6 +479,9 @@ ShapeFinder::visit_cell (const db::Cell &cell, const db::Box &hit_box, const db:
 {
   checkpoint ();
 
+  //  Viewport in current cell coordinate space (DBU)
+  db::Box viewport_box = (vp * db::CplxTrans (layout ().dbu ()) * t).inverted () * db::DBox (0, 0, view ()->viewport ().width (), view ()->viewport ().height ());
+
   if (! m_context_layers.empty ()) {
 
     std::map<db::cell_index_type, bool>::const_iterator ctx = m_cells_with_context.find (cell.cell_index ());
@@ -569,32 +572,40 @@ ShapeFinder::visit_cell (const db::Cell &cell, const db::Box &hit_box, const db:
           bool match = false;
           double d = std::numeric_limits<double>::max ();
 
-          checkpoint ();
-
           db::Point point (hit_box.center ());
 
           //  in point mode, test the edges and use a "closest" criterion
           if (shape->is_polygon ()) {
 
+            bool any_valid_edge = false;
             for (db::Shape::polygon_edge_iterator e = shape->begin_edge (); ! e.at_end (); ++e) {
-              test_edge (t, *e, d, match);
+              if ((*e).clipped (viewport_box).first) {
+                any_valid_edge = true;
+                test_edge (t, *e, d, match);
+              }
             }
 
             //  test if inside the polygon
-            if (! match && inside_poly (shape->begin_edge (), point) >= 0) { 
+            if (! match && any_valid_edge && inside_poly (shape->begin_edge (), point) >= 0) {
               d = t.ctrans (poly_dist (shape->begin_edge (), point)); 
               match = true;
             }
 
           } else if (shape->is_path ()) {
 
+            bool any_valid_edge = false;
+
             //  test the "spine"
-            db::Shape::point_iterator pt = shape->begin_point (); 
+            db::Shape::point_iterator pt = shape->begin_point ();
             if (pt != shape->end_point ()) {
               db::Point p (*pt);
               ++pt;
               for (; pt != shape->end_point (); ++pt) {
-                test_edge (t, db::Edge (p, *pt), d, match);
+                db::Edge e (p, *pt);
+                if (e.clipped (viewport_box).first) {
+                  any_valid_edge = true;
+                  test_edge (t, e, d, match);
+                }
                 p = *pt;
               }
             }
@@ -603,11 +614,14 @@ ShapeFinder::visit_cell (const db::Cell &cell, const db::Box &hit_box, const db:
             db::Polygon poly;
             shape->polygon (poly);
             for (db::Polygon::polygon_edge_iterator e = poly.begin_edge (); ! e.at_end (); ++e) {
-              test_edge (t, *e, d, match);
+              if ((*e).clipped (viewport_box).first) {
+                any_valid_edge = true;
+                test_edge (t, *e, d, match);
+              }
             }
 
             //  test if inside the polygon
-            if (! match && inside_poly (poly.begin_edge (), point) >= 0) { 
+            if (! match && any_valid_edge && inside_poly (poly.begin_edge (), point) >= 0) {
               d = t.ctrans (poly_dist (poly.begin_edge (), point));
               match = true;
             }
@@ -628,13 +642,18 @@ ShapeFinder::visit_cell (const db::Cell &cell, const db::Box &hit_box, const db:
               match = true;
             } else {
 
+              bool any_valid_edge = false;
+
               //  convert to polygon and test those edges
               db::Polygon poly (box);
               for (db::Polygon::polygon_edge_iterator e = poly.begin_edge (); ! e.at_end (); ++e) {
-                test_edge (t, *e, d, match);
+                if ((*e).clipped (viewport_box).first) {
+                  any_valid_edge = true;
+                  test_edge (t, *e, d, match);
+                }
               }
 
-              if (! match && box.contains (hit_box.center ())) {
+              if (! match && any_valid_edge && box.contains (hit_box.center ())) {
                 d = t.ctrans (poly_dist (poly.begin_edge (), point));
                 match = true;
               }
@@ -785,6 +804,8 @@ InstFinder::checkpoint ()
 void 
 InstFinder::visit_cell (const db::Cell &cell, const db::Box &search_box, const db::Box & /*scan_box*/, const db::DCplxTrans &vp, const db::ICplxTrans &t, int level)
 {
+  checkpoint ();
+
   //  Viewport in current cell coordinate space (DBU)
   db::Box viewport_box = (vp * db::CplxTrans (layout ().dbu ()) * t).inverted () * db::DBox (0, 0, view ()->viewport ().width (), view ()->viewport ().height ());
 
@@ -867,8 +888,6 @@ InstFinder::visit_cell (const db::Cell &cell, const db::Box &search_box, const d
 
   } else {
 
-    checkpoint ();
-
     //  look for instances to check here ..
     db::Cell::touching_iterator inst = cell.begin_touching (search_box); 
     while (! inst.at_end ()) {