diff --git a/cmd/suggestion/skopt/v1beta1/requirements.txt b/cmd/suggestion/skopt/v1beta1/requirements.txt
index 2cd9502447d..a924e4ccb2c 100644
--- a/cmd/suggestion/skopt/v1beta1/requirements.txt
+++ b/cmd/suggestion/skopt/v1beta1/requirements.txt
@@ -4,7 +4,7 @@ numpy>=1.20.0
 scikit-learn>=0.24.0
 scipy>=1.5.4
 forestci==0.3
-protobuf==3.19.1
+protobuf==3.19.5
 googleapis-common-protos==1.6.0
 scikit-optimize>=0.9.0
 cython>=0.29.24