diff --git a/Lesson01/activity_1/requirements.txt b/Lesson01/activity_1/requirements.txt
index c9eebbf..350ffa7 100644
--- a/Lesson01/activity_1/requirements.txt
+++ b/Lesson01/activity_1/requirements.txt
@@ -18,7 +18,7 @@ Flask-Cors==3.0.3
 Flask-Testing==0.7.1
 graphviz==0.8.1
 h5py==2.7.1
-html5lib==0.9999999
+html5lib==0.999999999
 idna==2.6
 ipykernel==4.7.0
 ipython==6.2.1