diff --git a/requirements.txt b/requirements.txt
index 9352990..cb57818 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -131,7 +131,7 @@ gym==0.10.8
 h5py==2.8.0
 heapdict==1.0.0
 howdoi==1.1.13
-html5lib==0.9999999
+html5lib==0.999999999
 httplib2==0.10.3
 idna==2.6
 imageio==2.2.0