diff --git a/requirements.txt b/requirements.txt
index 8c26eee4f2bc1a296c67af806c592d45720cd735..a134d2e7a3903536dc7f373959e53c76283d5077 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -27,8 +27,8 @@ django-sitetree>=1.8.0
 django-taggit==0.18.0
 django-timezone-field>=2.0
 easy-thumbnails>=2.4.1
-bleach
-pytz==2015.7
+bleach==2.1.3
+pytz==2018.4
 django-ical==1.4