diff --git a/tensorflow-client/python/requirements.txt b/tensorflow-client/python/requirements.txt
index 43f1250..273805a 100644
--- a/tensorflow-client/python/requirements.txt
+++ b/tensorflow-client/python/requirements.txt
@@ -2,4 +2,4 @@ requests==2.20.0
 tensorflow==1.7.1
 tensorflow-serving-api==1.7.1
 numpy==1.14.2
-protobuf==3.5.2
+protobuf==3.15.0
diff --git a/tensorflow-client/python/requirements_py3.txt b/tensorflow-client/python/requirements_py3.txt
index 9740268..5671abe 100644
--- a/tensorflow-client/python/requirements_py3.txt
+++ b/tensorflow-client/python/requirements_py3.txt
@@ -2,4 +2,4 @@ tensorflow==1.7.1
 tensorflow-serving-api-python3~=1.7.1
 requests==2.20.0
 numpy==1.14.2
-protobuf==3.5.2
+protobuf==3.15.0