diff --git a/requirements.txt b/requirements.txt
index 9c317e6..3b0452e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -21,7 +21,7 @@ gast==0.2.2
 glfw==1.7.1
 grpcio==1.11.0
 gym==0.10.11
-html5lib==0.9999999
+html5lib==0.999999999
 idna==2.8
 imageio==2.4.1
 ipykernel==5.1.0