diff --git a/images/linux/scripts/installers/ruby.sh b/images/linux/scripts/installers/ruby.sh
index bd260a55d..49273e62c 100644
--- a/images/linux/scripts/installers/ruby.sh
+++ b/images/linux/scripts/installers/ruby.sh
@@ -4,11 +4,18 @@
 ##  Desc:  Installs Ruby requirements and ruby gems
 ################################################################################
 
+source $HELPER_SCRIPTS/os.sh
 source $HELPER_SCRIPTS/install.sh
 
 apt-get install ruby-full
 gem update
 
+# temporary fix for fastlane installation https://github.com/fastlane/fastlane/issues/18642
+if isUbuntu20 ; then
+    gem uninstall rdoc
+    gem install rdoc -v 6.3.0
+fi
+
 # Install ruby gems from toolset
 gemsToInstall=$(get_toolset_value ".rubygems[] .name")
 if [ -n "$gemsToInstall" ]; then