diff --git a/requirements.txt b/requirements.txt
index ddee595..b34baac 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -9,7 +9,7 @@ Markdown==2.6.11
 numpy==1.14.2
 pandas==0.22.0
 patsy==0.5.0
-protobuf==3.5.2.post1
+protobuf==3.18.3
 python-dateutil==2.7.2
 pytz==2018.4
 scipy==1.0.1