diff --git a/Lesson04/activity_9/requirements.txt b/Lesson04/activity_9/requirements.txt
index df528f0..2238c8b 100644
--- a/Lesson04/activity_9/requirements.txt
+++ b/Lesson04/activity_9/requirements.txt
@@ -23,7 +23,7 @@ MarkupSafe==1.0
 nose==1.3.7
 numpy==1.13.3
 pandas==0.21.1
-protobuf==3.5.0.post1
+protobuf==3.18.3
 python-dateutil==2.6.1
 pytz==2017.3
 PyYAML==3.12