diff --git a/tools/distrib/python/grpcio_tools/setup.py b/tools/distrib/python/grpcio_tools/setup.py
index 9d64782fd00d6285c691e0dc020f019f9fa1a705..bb1f1cf085b65e3bf06e08d51440fd7e3e37cc21 100644
--- a/tools/distrib/python/grpcio_tools/setup.py
+++ b/tools/distrib/python/grpcio_tools/setup.py
@@ -143,11 +143,11 @@ def extension_modules():
     plugin_sources = [os.path.join('grpc', 'tools', '_protoc_compiler.pyx')]
   else:
     plugin_sources = [os.path.join('grpc', 'tools', '_protoc_compiler.cpp')]
-    plugin_sources += [
-      os.path.join('grpc', 'tools', 'main.cc'),
-      os.path.join('grpc_root', 'src', 'compiler', 'python_generator.cc')] + [
-      os.path.join(CC_INCLUDE, cc_file)
-      for cc_file in CC_FILES]
+  plugin_sources += [
+    os.path.join('grpc', 'tools', 'main.cc'),
+    os.path.join('grpc_root', 'src', 'compiler', 'python_generator.cc')] + [
+    os.path.join(CC_INCLUDE, cc_file)
+    for cc_file in CC_FILES]
   plugin_ext = extension.Extension(
       name='grpc.tools._protoc_compiler',
       sources=plugin_sources,