diff --git a/word-o-mat.glyphsPlugin/Contents/Resources/WordOMat.py b/word-o-mat.glyphsPlugin/Contents/Resources/WordOMat.py
index 668d2ef..97b9b81 100755
--- a/word-o-mat.glyphsPlugin/Contents/Resources/WordOMat.py
+++ b/word-o-mat.glyphsPlugin/Contents/Resources/WordOMat.py
@@ -810,8 +810,11 @@ def fontClosed(self, info):
          
     def windowClose(self, sender):
         """Remove observers when the extension window is closed."""
-        removeObserver(self, "fontDidOpen")
-        removeObserver(self, "fontWillClose")
+        try:
+            removeObserver(self, "fontDidOpen")
+            removeObserver(self, "fontWillClose")
+        except:
+            pass
 
 GlyphsPlugin = objc.protocolNamed('GlyphsPlugin')
 class WordOMat(NSObject, GlyphsPlugin):
@@ -844,4 +847,4 @@ def showWindow(self):
         if not self.wordomat or not self.wordomat.w._window:
             self.wordomat = WordomatWindow()
         else:
-            self.wordomat.w.show()
\ No newline at end of file
+            self.wordomat.w.show()