diff --git a/test/distrib/cpp/run_distrib_test.sh b/test/distrib/cpp/run_distrib_test.sh
index dfe9867a602ca604bd3e63246347e17024f098de..bc84b84b8f37ab90e9130eb811de4bc9c394a091 100755
--- a/test/distrib/cpp/run_distrib_test.sh
+++ b/test/distrib/cpp/run_distrib_test.sh
@@ -30,13 +30,13 @@
 
 set -ex
 
-git clone $EXTERNAL_GIT_ROOT
-cd grpc && git submodule update --init
+git clone --recursive $EXTERNAL_GIT_ROOT
+cd grpc
 
 cd third_party/protobuf && ./autogen.sh && \
-./configure && make -j12 && make check && make install && ldconfig
+./configure && make -j4 && make check && make install && ldconfig
 
-cd ../.. && make -j12 && make install
+cd ../.. && make -j4 && make install
 
 cd examples/cpp/helloworld
 
diff --git a/tools/dockerfile/distribtest/cpp_jessie_x64/Dockerfile b/tools/dockerfile/distribtest/cpp_jessie_x64/Dockerfile
index b02208faed1ae968c64d961191f9383bb0ab8523..c24b1c451d3b56568de7dd1c4ae5e905a0432ad6 100644
--- a/tools/dockerfile/distribtest/cpp_jessie_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/cpp_jessie_x64/Dockerfile
@@ -29,7 +29,7 @@
 
 FROM debian:jessie
 
-# Install packages for gRPC and protobuf
+# Install packages needed for gRPC and protobuf
 RUN apt-get update && apt-get install -y \
       autoconf \
       automake \