diff --git a/grpc-django-book-service/requirements.txt b/grpc-django-book-service/requirements.txt
index 8e06fe8..17448b1 100644
--- a/grpc-django-book-service/requirements.txt
+++ b/grpc-django-book-service/requirements.txt
@@ -67,7 +67,7 @@ pexpect==4.6.0
 pickleshare==0.7.4
 poyo==0.4.1
 prompt-toolkit==1.0.15
-protobuf==3.6.0
+protobuf==3.18.3
 ptyprocess==0.6.0
 Pygments==2.2.0
 pykerberos==1.2.1