diff --git a/doc/users/navigation_toolbar.rst b/doc/users/navigation_toolbar.rst
index 8140874775d..8902873b949 100644
--- a/doc/users/navigation_toolbar.rst
+++ b/doc/users/navigation_toolbar.rst
@@ -112,6 +112,8 @@ depends on your UI, but we have examples for every supported UI in the
 example code for GTK::
 
 
+    import gtk
+
     from matplotlib.figure import Figure
     from matplotlib.backends.backend_gtkagg import FigureCanvasGTKAgg as FigureCanvas
     from matplotlib.backends.backend_gtkagg import NavigationToolbar2GTKAgg as NavigationToolbar