diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 9552d0551..61b1d3034 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -389,6 +389,9 @@ stages:
       - bash: |
           if [[ $OSNAME == "Mac" ]]; then
           url=https://github.com/mozilla/geckodriver/releases/download/v0.24.0/geckodriver-v0.24.0-macos.tar.gz
+          brew update
+          brew tap caskroom/cask
+          brew cask install firefox
           elif [[ $OSNAME == "Linux" ]]; then
           url=https://github.com/mozilla/geckodriver/releases/download/v0.24.0/geckodriver-v0.24.0-linux64.tar.gz
           else