diff --git a/src/libprs500/ebooks/__init__.py b/src/libprs500/ebooks/__init__.py
index 41830329fb..25a6c4c315 100644
--- a/src/libprs500/ebooks/__init__.py
+++ b/src/libprs500/ebooks/__init__.py
@@ -24,5 +24,6 @@ class ConversionError(Exception):
 class UnknownFormatError(Exception):
     pass
 
-BOOK_EXTENSIONS = ['lrf', 'lrx', 'rar', 'zip', 'rtf', 'lit', 'txt', 'htm', 
-                   'html', 'xhtml', 'epub', 'pdf', 'prc', 'mobi', 'azw', 'epub']
+BOOK_EXTENSIONS = ['lrf', 'lrx', 'rar', 'zip', 'rtf', 'lit', 'txt', 'htm', 'xhtm', 
+                   'html', 'xhtml', 'epub', 'pdf', 'prc', 'mobi', 'azw', 
+                   'epub']