diff --git a/requirements.txt b/requirements.txt
index 57cf618..ae98da5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -22,7 +22,7 @@ jws==0.1.3
 MarkupSafe==1.0
 msgpack==0.5.6
 oauth2client==3.0.0
-protobuf==3.6.1
+protobuf==3.15.0
 pyasn1==0.4.4
 pyasn1-modules==0.2.2
 pycryptodome==3.7.2