diff --git a/boxes.py b/boxes.py
index 65a168a..922de22 100755
--- a/boxes.py
+++ b/boxes.py
@@ -3,6 +3,8 @@
 import cairo
 import math
 
+def dist(dx, dy):
+    return (dx*dx+dy*dy)**0.5
 
 class Boxes:
 
@@ -301,12 +303,25 @@ class Boxes:
 
     def __skipcircle(self, x, y, r, b, posx, posy):
         cx, cy = x/2.0, y/2.0
-        return ((((posx-cx)**2+(posy-cy)**2)**0.5) > (cx-r))
+        return (dist(posx-cx, posy-cy) > (cx-r))
 
     def hexHolesCircle(self, d, r, b, style="circle"):
         d2 = d/2.0
         self.hexHolesRectangle(d, d, r, b, style, self.__skipcircle)
 
+    def hexHolesPlate(self, x, y, er, r, b, style='circle'):
+        def skip(x, y, r, b, posx, posy):
+            posx = abs(posx-(x/2.0))
+            posy = abs(posy-(y/2.0))
+
+            wx = 0.5*x-er-r
+            wy = 0.5*y-er-r
+
+            if (posx <= wx) or (posy <= wx):
+                return 0
+            return dist(posx-wx, posy-wy) > er
+
+        self.hexHolesRectangle(x, y, r, b, style, skip=skip)
 
     def hexHolesHex(self, h, r, b, style="circle", grow=None):
         self.ctx.rectangle(0, 0, h, h)
diff --git a/lamp.py b/lamp.py
index 72fa813..413f69e 100755
--- a/lamp.py
+++ b/lamp.py
@@ -21,7 +21,7 @@ class Lamp(Boxes):
         d = 2*(r+w)
         self.roundedPlate(d, d, r)
         self.moveTo(w/2.0, w/2.0)
-        self.hexHolesCircle(d-w, 5, 3)
+        self.hexHolesPlate(d-w, d-w, r-w/2.0, 5, 3)
         self.ctx.restore()
 
     def render(self, r, w):