diff --git a/SketchWidget.py b/SketchWidget.py
index cf20895..4e6d923 100644
--- a/SketchWidget.py
+++ b/SketchWidget.py
@@ -367,8 +367,7 @@ class SketchWidget:
                 else:
                     self.widget.window.set_cursor(self.cursors['arrow'])
             self.mode = mode
-            self.drawingShape = None
-            self.drawingConstraints = []
+            self.cancel_drawing_shape()
 
     def do_line_left_click(self, x, y):
         start = self.screenPtToPt((x, self.size[1] - y))
@@ -380,8 +379,7 @@ class SketchWidget:
 
     def do_line_right_click(self, x, y):
         if self.drawingShape is not None:
-            # cancel line currently being drawn
-            self.drawingShape = None
+            self.cancel_drawing_shape()
             self.queue_redraw()
 
     def do_line_motion(self, x, y):
@@ -421,8 +419,7 @@ class SketchWidget:
 
     def do_circle_right_click(self, x, y):
         if self.drawingShape is not None:
-            # cancel circle currently being drawn
-            self.drawingShape = None
+            self.cancel_drawing_shape()
             self.queue_redraw()
 
     def do_circle_motion(self, x, y):
@@ -431,6 +428,10 @@ class SketchWidget:
         self.drawingShape.setRadius(r)
         self.queue_redraw()
 
+    def cancel_drawing_shape(self):
+        self.drawingShape = None
+        self.drawingConstraints = []
+
     def merge_in_drawing_shape(self):
         self.sketch.shapes.append(self.drawingShape)
         for c in self.drawingConstraints: