diff --git a/requirements.txt b/requirements.txt
index 1b26122..5f1c924 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,5 +5,5 @@ googleapis-common-protos==1.5.3
 grpcio==1.8.4
 grpcio-tools==1.12.1
 nose==1.3.7
-protobuf==3.5.2
+protobuf==3.15.8
 six==1.11.0