diff --git a/src/proto/grpc/testing/echo.proto b/src/proto/grpc/testing/echo.proto
index c596aabfcc445f06f7c6c7f44efdad2b3b7db1a8..ca60a41b4fffded28418fe8425380f57879e9738 100644
--- a/src/proto/grpc/testing/echo.proto
+++ b/src/proto/grpc/testing/echo.proto
@@ -42,7 +42,7 @@ service EchoTestService {
   rpc Unimplemented(EchoRequest) returns (EchoResponse);
 }
 
-service UnimplementedService {
+service UnimplementedEchoService {
   rpc Unimplemented(EchoRequest) returns (EchoResponse);
 }
 
diff --git a/test/cpp/end2end/async_end2end_test.cc b/test/cpp/end2end/async_end2end_test.cc
index 4a8936d281020bbd4986eceb26c8ead83d177d46..27673c4ea1981c0656329fb50f345588feb0aaa5 100644
--- a/test/cpp/end2end/async_end2end_test.cc
+++ b/test/cpp/end2end/async_end2end_test.cc
@@ -898,8 +898,8 @@ TEST_P(AsyncEnd2endTest, UnimplementedRpc) {
       GetChannelCredentials(GetParam().credentials_type, &args);
   std::shared_ptr<Channel> channel =
       CreateCustomChannel(server_address_.str(), channel_creds, args);
-  std::unique_ptr<grpc::testing::UnimplementedService::Stub> stub;
-  stub = grpc::testing::UnimplementedService::NewStub(channel);
+  std::unique_ptr<grpc::testing::UnimplementedEchoService::Stub> stub;
+  stub = grpc::testing::UnimplementedEchoService::NewStub(channel);
   EchoRequest send_request;
   EchoResponse recv_response;
   Status recv_status;
diff --git a/test/cpp/end2end/end2end_test.cc b/test/cpp/end2end/end2end_test.cc
index 0f87ae3e440df2261972defb574d06cda96c0caa..683a71583af659b6fa001684ecb97ac44fda609b 100644
--- a/test/cpp/end2end/end2end_test.cc
+++ b/test/cpp/end2end/end2end_test.cc
@@ -967,8 +967,8 @@ TEST_P(End2endTest, ChannelStateTimeout) {
 // Talking to a non-existing service.
 TEST_P(End2endTest, NonExistingService) {
   ResetChannel();
-  std::unique_ptr<grpc::testing::UnimplementedService::Stub> stub;
-  stub = grpc::testing::UnimplementedService::NewStub(channel_);
+  std::unique_ptr<grpc::testing::UnimplementedEchoService::Stub> stub;
+  stub = grpc::testing::UnimplementedEchoService::NewStub(channel_);
 
   EchoRequest request;
   EchoResponse response;
diff --git a/test/cpp/end2end/hybrid_end2end_test.cc b/test/cpp/end2end/hybrid_end2end_test.cc
index 7e0c0e8a7ca3bf8326f749aefe17db0b3cbeab44..77b0e1f40ecbcea5eadffdab0cddaf49f199eb9e 100644
--- a/test/cpp/end2end/hybrid_end2end_test.cc
+++ b/test/cpp/end2end/hybrid_end2end_test.cc
@@ -346,7 +346,7 @@ class HybridEnd2endTest : public ::testing::Test {
     EXPECT_TRUE(s.ok());
   }
 
-  grpc::testing::UnimplementedService::Service unimplemented_service_;
+  grpc::testing::UnimplementedEchoService::Service unimplemented_service_;
   std::vector<std::unique_ptr<ServerCompletionQueue>> cqs_;
   std::unique_ptr<grpc::testing::EchoTestService::Stub> stub_;
   std::unique_ptr<Server> server_;