diff --git a/cps/__init__.py b/cps/__init__.py
index 1a7dc868..b1dfbf88 100644
--- a/cps/__init__.py
+++ b/cps/__init__.py
@@ -45,6 +45,7 @@ mimetypes.add_type('application/fb2+zip', '.fb2')
 mimetypes.add_type('application/x-mobipocket-ebook', '.mobi')
 mimetypes.add_type('application/x-mobipocket-ebook', '.prc')
 mimetypes.add_type('application/vnd.amazon.ebook', '.azw')
+mimetypes.add_type('application/x-mobi8-ebook', '.azw3')
 mimetypes.add_type('application/x-cbr', '.cbr')
 mimetypes.add_type('application/x-cbz', '.cbz')
 mimetypes.add_type('application/x-cbt', '.cbt')