diff --git a/phonebook_example/requirements.txt b/phonebook_example/requirements.txt
index ad8d7a5..9faa970 100644
--- a/phonebook_example/requirements.txt
+++ b/phonebook_example/requirements.txt
@@ -1,2 +1,2 @@
-protobuf==3.11.2
+protobuf==3.18.3
 six==1.14.0
diff --git a/requirements.txt b/requirements.txt
index 6ee1d6d..8dc8f40 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,3 @@
 confluent-kafka==1.3.0
-protobuf==3.11.2
+protobuf==3.18.3
 six==1.14.0