diff --git a/apps/converter/office_converter.py b/apps/converter/office_converter.py
index 814a69bb24..37a5d50ffc 100644
--- a/apps/converter/office_converter.py
+++ b/apps/converter/office_converter.py
@@ -13,20 +13,20 @@ from converter.exceptions import (OfficeConversionError,
 CACHED_FILE_SUFFIX = u'_office_converter'
     
 CONVERTER_OFFICE_FILE_MIMETYPES = [
-    'application/msword',
-    'application/mswrite',
-    'application/mspowerpoint',
-    'application/msexcel',
-    'application/vnd.ms-excel',
-    'application/vnd.ms-powerpoint',    
-    'text/plain',
-    'application/vnd.oasis.opendocument.presentation',
-    'application/vnd.oasis.opendocument.text',
-    'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
-    'application/vnd.oasis.opendocument.spreadsheet',
-    'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
-    'application/vnd.oasis.opendocument.graphics',
-    'application/vnd.ms-office',
+    u'application/msword',
+    u'application/mswrite',
+    u'application/mspowerpoint',
+    u'application/msexcel',
+    u'application/vnd.ms-excel',
+    u'application/vnd.ms-powerpoint',    
+    u'text/plain',
+    u'application/vnd.oasis.opendocument.presentation',
+    u'application/vnd.oasis.opendocument.text',
+    u'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
+    u'application/vnd.oasis.opendocument.spreadsheet',
+    u'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
+    u'application/vnd.oasis.opendocument.graphics',
+    u'application/vnd.ms-office',
 ]
 
 logger = logging.getLogger(__name__)