diff --git a/chaco/shell/plot_window.py b/chaco/shell/plot_window.py
index 4e78c4447..6877cd5ba 100644
--- a/chaco/shell/plot_window.py
+++ b/chaco/shell/plot_window.py
@@ -243,7 +243,7 @@ def closeEvent(self, event):
     class PlotWindow(object):
 
         def __init__(self, *args, **kwargs):
-            raise NotImplmentedError(
+            raise NotImplementedError(
                 'PlotWindow not implemented for `null` toolkit')
 
 # EOF