diff --git a/markdownx/forms.py b/markdownx/forms.py
index 4cd60a3..9792f2e 100755
--- a/markdownx/forms.py
+++ b/markdownx/forms.py
@@ -24,7 +24,7 @@ class ImageForm(forms.Form):
 
     def save(self, commit=True):
         img = scale_and_crop(self.files['image'], **MARKDOWNX_IMAGE_MAX_SIZE)
-        thumb_io = StringIO.StringIO()
+        thumb_io = StringIO()
         img.save(thumb_io,  self.files['image'].content_type.split('/')[-1].upper())
 
         file_name = str(self.files['image'])