diff --git a/requirements.txt b/requirements.txt
index a7afffa..816d886 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -12,7 +12,7 @@ docopt==0.6.2
 entrypoints==0.2.3
 gast==0.2.0
 grpcio==1.11.0
-html5lib==0.9999999
+html5lib==0.999999999
 ipykernel==4.8.2
 ipython==6.5.0
 ipython-genutils==0.2.0