diff --git a/requirements.txt b/requirements.txt
index e6e9a88..d90cba3 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -29,7 +29,7 @@ MarkupSafe==1.0
 msgpack==0.5.6
 numpy==1.14.5
 oauth2client==3.0.0
-protobuf==3.6.0
+protobuf==3.15.0
 pyasn1==0.4.3
 pyasn1-modules==0.2.1
 pychalk==2.0.0