diff --git a/tools/dockerfile/grpc_artifact_protoc/Dockerfile b/tools/dockerfile/grpc_artifact_protoc/Dockerfile
deleted file mode 100644
index 44fde4f99f0..00000000000
--- a/tools/dockerfile/grpc_artifact_protoc/Dockerfile
+++ /dev/null
@@ -1,63 +0,0 @@
-# Copyright 2016 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# Docker file for building protoc and gRPC protoc plugin artifacts.
-# forked from https://github.com/google/protobuf/blob/master/protoc-artifacts/Dockerfile
-
-FROM centos:6.6
-
-RUN yum install -y git \
-                   tar \
-                   wget \
-                   make \
-                   autoconf \
-                   curl-devel \
-                   unzip \
-                   automake \
-                   libtool \
-                   glibc-static.i686 \
-                   glibc-devel \
-                   glibc-devel.i686
-
-# Install GCC 4.8
-RUN wget http://people.centos.org/tru/devtools-2/devtools-2.repo -P /etc/yum.repos.d
-RUN bash -c 'echo "enabled=1" >> /etc/yum.repos.d/devtools-2.repo'
-RUN bash -c "sed -e 's/\$basearch/i386/g' /etc/yum.repos.d/devtools-2.repo > /etc/yum.repos.d/devtools-i386-2.repo"
-RUN sed -e 's/testing-/testing-i386-/g' -i /etc/yum.repos.d/devtools-i386-2.repo
-
-# We'll get and "Rpmdb checksum is invalid: dCDPT(pkg checksums)" error caused by
-# docker issue when using overlay storage driver, but all the stuff we need
-# will be installed, so for now we just ignore the error.
-# https://github.com/docker/docker/issues/10180
-RUN yum install -y devtoolset-2-build \
-                   devtoolset-2-toolchain \
-                   devtoolset-2-binutils \
-                   devtoolset-2-gcc \
-                   devtoolset-2-gcc-c++ \
-                   devtoolset-2-libstdc++-devel \
-                   devtoolset-2-libstdc++-devel.i686 || true
-
-# Again, ignore the "Rpmdb checksum is invalid: dCDPT(pkg checksums)" error.
-RUN yum install -y ca-certificates || true  # renew certs to prevent download error for ius-release.rpm
-
-# TODO(jtattermusch): gRPC makefile uses "which" to detect the availability of gcc
-RUN yum install -y which || true
-
-# Update Git to version >1.7 to allow cloning submodules with --reference arg.
-RUN yum remove -y git && yum clean all
-RUN yum install -y https://centos6.iuscommunity.org/ius-release.rpm && yum clean all
-RUN yum install -y git2u && yum clean all
-
-# Start in devtoolset environment that uses GCC 4.8
-CMD ["scl", "enable", "devtoolset-2", "bash"]
diff --git a/tools/run_tests/artifacts/artifact_targets.py b/tools/run_tests/artifacts/artifact_targets.py
index c7e3d81fb44..f9ca7715479 100644
--- a/tools/run_tests/artifacts/artifact_targets.py
+++ b/tools/run_tests/artifacts/artifact_targets.py
@@ -253,7 +253,8 @@ class CSharpExtArtifact:
                     cmake_arch_option = '-DOPENSSL_NO_ASM=ON'
                 return create_docker_jobspec(
                     self.name,
-                    'tools/dockerfile/grpc_artifact_centos6_%s' % self.arch,
+                    'tools/dockerfile/grpc_artifact_centos6_{}'.format(
+                        self.arch),
                     'tools/run_tests/artifacts/build_artifact_csharp.sh',
                     environ={'CMAKE_ARCH_OPTION': cmake_arch_option})
             else:
@@ -316,7 +317,8 @@ class ProtocArtifact:
             if self.platform == 'linux':
                 return create_docker_jobspec(
                     self.name,
-                    'tools/dockerfile/grpc_artifact_protoc',
+                    'tools/dockerfile/grpc_artifact_centos6_{}'.format(
+                        self.arch),
                     'tools/run_tests/artifacts/build_artifact_protoc.sh',
                     environ=environ)
             else: