diff --git a/requirements.txt b/requirements.txt
index 1566323..8a65d90 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -12,7 +12,7 @@ google-cloud-dns==0.33.0
 googleapis-common-protos==1.53.0
 httplib2==0.19.1
 idna==3.2
-protobuf==3.17.3
+protobuf==3.18.3
 pyasn1==0.4.8
 pyasn1-modules==0.2.8
 pyparsing==2.4.7