diff --git a/tools/internal_ci/helper_scripts/prepare_build_macos_rc b/tools/internal_ci/helper_scripts/prepare_build_macos_rc
index 5b6b2569393..7b9b02b6318 100644
--- a/tools/internal_ci/helper_scripts/prepare_build_macos_rc
+++ b/tools/internal_ci/helper_scripts/prepare_build_macos_rc
@@ -40,6 +40,7 @@ fi
 set +ex  # rvm script is very verbose and exits with errorcode
 # Advice from https://github.com/Homebrew/homebrew-cask/issues/8629#issuecomment-68641176
 brew update && brew upgrade brew-cask && brew cleanup && brew cask cleanup
+rvm --debug requirements ruby-2.5.0
 source $HOME/.rvm/scripts/rvm
 set -e  # rvm commands are very verbose
 time rvm install 2.5.0