5 files changed, 5 insertions, 5 deletions
diff --git a/src/csharp/Grpc.Core/Version.csproj.include b/src/csharp/Grpc.Core/Version.csproj.include
index f7a7a5cbe9..6e28c11df2 100755
--- a/src/csharp/Grpc.Core/Version.csproj.include
+++ b/src/csharp/Grpc.Core/Version.csproj.include
@@ -2,6 +2,6 @@
 <Project>
   <PropertyGroup>
     <GrpcCsharpVersion>1.12.0-dev</GrpcCsharpVersion>
-    <GoogleProtobufVersion>3.3.0</GoogleProtobufVersion>
+    <GoogleProtobufVersion>3.5.1</GoogleProtobufVersion>
   </PropertyGroup>
 </Project>
diff --git a/src/python/grpcio_health_checking/setup.py b/src/python/grpcio_health_checking/setup.py
index 60d309ec65..35c09827ba 100644
--- a/src/python/grpcio_health_checking/setup.py
+++ b/src/python/grpcio_health_checking/setup.py
@@ -57,7 +57,7 @@ PACKAGE_DIRECTORIES = {
 }
 
 INSTALL_REQUIRES = (
-    'protobuf>=3.5.0.post1',
+    'protobuf>=3.5.2.post1',
     'grpcio>={version}'.format(version=grpc_version.VERSION),
 )
 
diff --git a/src/python/grpcio_reflection/setup.py b/src/python/grpcio_reflection/setup.py
index 10c4c38f19..589d0ff556 100644
--- a/src/python/grpcio_reflection/setup.py
+++ b/src/python/grpcio_reflection/setup.py
@@ -58,7 +58,7 @@ PACKAGE_DIRECTORIES = {
 }
 
 INSTALL_REQUIRES = (
-    'protobuf>=3.5.0.post1',
+    'protobuf>=3.5.2.post1',
     'grpcio>={version}'.format(version=grpc_version.VERSION),
 )
 
diff --git a/src/python/grpcio_testing/setup.py b/src/python/grpcio_testing/setup.py
index 5a9d593ec1..eb480a5464 100644
--- a/src/python/grpcio_testing/setup.py
+++ b/src/python/grpcio_testing/setup.py
@@ -29,7 +29,7 @@ PACKAGE_DIRECTORIES = {
 }
 
 INSTALL_REQUIRES = (
-    'protobuf>=3.5.0.post1',
+    'protobuf>=3.5.2.post1',
     'grpcio>={version}'.format(version=grpc_version.VERSION),
 )
 
diff --git a/src/python/grpcio_tests/setup.py b/src/python/grpcio_tests/setup.py
index 4e0f6726fa..98ac19d188 100644
--- a/src/python/grpcio_tests/setup.py
+++ b/src/python/grpcio_tests/setup.py
@@ -41,7 +41,7 @@ INSTALL_REQUIRES = (
     'grpcio>={version}'.format(version=grpc_version.VERSION),
     'grpcio-tools>={version}'.format(version=grpc_version.VERSION),
     'grpcio-health-checking>={version}'.format(version=grpc_version.VERSION),
-    'oauth2client>=1.4.7', 'protobuf>=3.5.0.post1', 'six>=1.10',
+    'oauth2client>=1.4.7', 'protobuf>=3.5.2.post1', 'six>=1.10',
     'google-auth>=1.0.0', 'requests>=2.14.2')
 
 COMMAND_CLASS = {