diff --git a/requirements.txt b/requirements.txt
index 5c491f98e..19d4eea57 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -29,5 +29,5 @@ pytz>=2014.7
 six>=1.8.0
 Unidecode>=0.4.18
 #wsgiref>=0.1.2
-xml2rfc>=2.5.0
-xym>=0.1.2
+xml2rfc>=2.5.
+xym>=0.1.2,!=0.3