diff --git a/requirements.txt b/requirements.txt
index c607615..a296df2 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -19,7 +19,7 @@ grpcio==1.30.0
 httplib2==0.18.1
 idna==2.10
 msgpack==1.0.0
-protobuf==3.12.2
+protobuf==3.18.3
 pyasn1==0.4.8
 pyasn1-modules==0.2.8
 pycparser==2.20