diff --git a/requirements.txt b/requirements.txt
index 25b717a..75fe3ad 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,7 +4,7 @@ html5lib==0.9999999
 Markdown==2.6.11
 numpy==1.13.3
 pandas==0.19.0
-protobuf==3.5.1
+protobuf==3.15.0
 python-dateutil==2.6.1
 pytz==2018.3
 scikit-learn==0.19.1