diff --git a/tools/internal_ci/helper_scripts/prepare_build_macos_rc b/tools/internal_ci/helper_scripts/prepare_build_macos_rc
index 22e80d2afa1d6f8316fa368fc7d6e64593555bf3..7d2c5221d1a982a766f100600466ed8bab4f9fb2 100644
--- a/tools/internal_ci/helper_scripts/prepare_build_macos_rc
+++ b/tools/internal_ci/helper_scripts/prepare_build_macos_rc
@@ -15,7 +15,12 @@
 
 # Source this rc script to prepare the environment for macos builds
 
-ulimit -n 1000
+sudo launchctl limit maxfiles unlimited unlimited
+
+# show current maxfiles
+launchctl limit maxfiles
+
+ulimit -n 10000
 
 # show current limits
 ulimit -a
@@ -37,6 +42,7 @@ gem install bundler
 # cocoapods
 export LANG=en_US.UTF-8
 gem install cocoapods
+gem install xcpretty
 pod repo update  # needed by python
 
 # python
@@ -48,4 +54,7 @@ sudo pip install -U six tox setuptools
 wget -q https://www.python.org/ftp/python/3.4.4/python-3.4.4-macosx10.6.pkg
 sudo installer -pkg python-3.4.4-macosx10.6.pkg -target /
 
+# set xcode version for Obj-C tests
+sudo xcode-select -switch /Applications/Xcode_8.2.1.app/Contents/Developer
+
 git submodule update --init