diff --git a/SketchWidget.py b/SketchWidget.py
index f71e08c..0758eb4 100644
--- a/SketchWidget.py
+++ b/SketchWidget.py
@@ -500,6 +500,7 @@ class SketchWidget:
                 self.sketch.constraints.append(self.drawingConstraints[c])
         self.drawingShape = None
         self.drawingConstraints = {}
+        self.invalidate()
 
     def dist_bw(self, pt1, pt2):
         x = pt2[0] - pt1[0]
@@ -557,6 +558,10 @@ class SketchWidget:
                 self.hover_snap_ptref = None
                 self.queue_redraw()
 
+    def invalidate(self):
+        self.solved = False
+        self.solve()
+
     def solve(self):
         if not self.solved:
             result = self.sketch.solve()