diff --git a/requirements.txt b/requirements.txt
index 68a4c4f..9f061f7 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,7 +4,7 @@ certifi==2018.8.24
 html5lib==0.9999999
 Markdown==3.0.1
 numpy==1.16.2
-protobuf==3.7.0
+protobuf==3.18.3
 scikit-learn==0.20.3
 scipy==1.2.1
 six==1.12.0