diff --git a/requirements.txt b/requirements.txt
index 4df880b..c45884a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -20,7 +20,7 @@ itsdangerous==1.1.0
 Jinja2==2.11.3
 MarkupSafe==1.1.1
 oauth2client==4.1.3
-protobuf==3.15.0
+protobuf==3.18.3
 pyasn1==0.4.8
 pyasn1-modules==0.2.8
 pytz==2020.1