diff --git a/requirements.txt b/requirements.txt
index 775a7ac..4064472 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -24,7 +24,7 @@ glfw==1.7.1
 gpflow==1.1.0
 grpcio==1.20.1
 gym==0.10.5
-html5lib==0.9999999
+html5lib==0.99999999
 idna==2.8
 imageio==2.5.0
 imagesize==1.1.0