diff --git a/lib/matplotlib/backends/backend_gtk.py b/lib/matplotlib/backends/backend_gtk.py
index 05d2f9d6d560..d71365244d96 100644
--- a/lib/matplotlib/backends/backend_gtk.py
+++ b/lib/matplotlib/backends/backend_gtk.py
@@ -832,7 +832,7 @@ def __init__ (self,
         hbox.pack_start (cbox)
 
         self.filetypes = filetypes
-        self.sorted_filetypes = list(six.iteritems(filetypes.items))
+        self.sorted_filetypes = list(six.iteritems(filetypes))
         self.sorted_filetypes.sort()
         default = 0
         for i, (ext, name) in enumerate(self.sorted_filetypes):