diff --git a/MiRCARTToolFill.py b/MiRCARTToolFill.py
index 9235275..c1adc8c 100644
--- a/MiRCARTToolFill.py
+++ b/MiRCARTToolFill.py
@@ -31,7 +31,7 @@ class MiRCARTToolFill(MiRCARTTool):
     #
     # onMouseEvent(self, event, atPoint, brushColours, brushSize, isDragging, isLeftDown, isRightDown, dispatchFn, eventDc): XXX
     def onMouseEvent(self, event, atPoint, brushColours, brushSize, isDragging, isLeftDown, isRightDown, dispatchFn, eventDc):
-        pointStack = [list(atPoint)]
+        pointStack = [list(atPoint)]; pointsDone = [];
         testColour = self.parentCanvas.canvasMap[atPoint[1]][atPoint[0]][0][1]
         if isLeftDown or isRightDown:
             if isRightDown:
@@ -40,15 +40,17 @@ class MiRCARTToolFill(MiRCARTTool):
                 point = pointStack.pop()
                 pointCell = self.parentCanvas.canvasMap[point[1]][point[0]]
                 if pointCell[0][1] == testColour:
-                    dispatchFn(eventDc, False, [point.copy(),   \
-                        [brushColours[0], brushColours[0]], 0, " "])
-                    if point[0] > 0:
-                        pointStack.append([point[0] - 1, point[1]])
-                    if point[0] < (self.parentCanvas.canvasSize[0] - 1):
-                        pointStack.append([point[0] + 1, point[1]])
-                    if point[1] > 0:
-                        pointStack.append([point[0], point[1] - 1])
-                    if point[1] < (self.parentCanvas.canvasSize[1] - 1):
-                        pointStack.append([point[0], point[1] + 1])
+                    if not point in pointsDone:
+                        dispatchFn(eventDc, False, [point.copy(),   \
+                            [brushColours[0], brushColours[0]], 0, " "])
+                        if point[0] > 0:
+                            pointStack.append([point[0] - 1, point[1]])
+                        if point[0] < (self.parentCanvas.canvasSize[0] - 1):
+                            pointStack.append([point[0] + 1, point[1]])
+                        if point[1] > 0:
+                            pointStack.append([point[0], point[1] - 1])
+                        if point[1] < (self.parentCanvas.canvasSize[1] - 1):
+                            pointStack.append([point[0], point[1] + 1])
+                        pointsDone += [point]
 
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