diff --git a/Lesson-1/activity_1/requirements.txt b/Lesson-1/activity_1/requirements.txt
index 424e5fb..03430b6 100644
--- a/Lesson-1/activity_1/requirements.txt
+++ b/Lesson-1/activity_1/requirements.txt
@@ -57,7 +57,7 @@ Pygments==2.2.0
 pyparsing==2.2.0
 python-dateutil==2.6.1
 pytz==2017.3
-PyYAML==3.12
+PyYAML==5.4
 pyzmq==16.0.3
 qtconsole==4.3.1
 redis==2.10.6