diff --git a/Library/Homebrew/utils/ruby.sh b/Library/Homebrew/utils/ruby.sh
index d596ce2d91..284a8e581b 100644
--- a/Library/Homebrew/utils/ruby.sh
+++ b/Library/Homebrew/utils/ruby.sh
@@ -13,7 +13,7 @@ setup-ruby-path() {
   # When bumping check if HOMEBREW_MACOS_SYSTEM_RUBY_NEW_ENOUGH (in brew.sh)
   # also needs to be changed.
   local required_ruby_version="2.6"
-  local old_ruby_path ruby_clean_path ruby_user_path
+  local ruby_exec
   local advice="
 If there's no Homebrew Portable Ruby available for your processor:
 - install Ruby $required_ruby_version with your system package manager (or rbenv/ruby-build)
@@ -25,8 +25,6 @@ If there's no Homebrew Portable Ruby available for your processor:
   vendor_ruby_current_version="$vendor_dir/portable-ruby/current"
   vendor_ruby_path="$vendor_ruby_current_version/bin/ruby"
 
-  [[ -n $HOMEBREW_RUBY_PATH ]] && old_ruby_path=$HOMEBREW_RUBY_PATH
-
   unset HOMEBREW_RUBY_PATH
 
   if [[ "$HOMEBREW_COMMAND" != "vendor-install" ]]
@@ -52,17 +50,16 @@ If there's no Homebrew Portable Ruby available for your processor:
       then
         HOMEBREW_RUBY_PATH="/System/Library/Frameworks/Ruby.framework/Versions/Current/usr/bin/ruby"
       else
-        ruby_clean_path=$(type -P ruby)
-        ruby_user_path=$(PATH="$HOMEBREW_PATH" type -P ruby)
-        if [[ $(test-ruby "$old_ruby_path") == "true" ]]; then
-          HOMEBREW_RUBY_PATH=$old_ruby_path
-        elif [[ $(test-ruby "$ruby_clean_path") == "true" ]]; then
-          HOMEBREW_RUBY_PATH=$ruby_clean_path
-        elif [[ $(test-ruby "$ruby_user_path") == "true" ]]; then
-          HOMEBREW_RUBY_PATH=$ruby_user_path
-        else
-          onoe "Failed to find usable Ruby $required_ruby_version!"
-        fi
+        IFS=$'\n'
+        for ruby_exec in $(which -a ruby) $(PATH=$HOMEBREW_PATH which -a ruby)
+        do
+          if [[ $(test-ruby "$ruby_exec") == "true" ]]; then
+            HOMEBREW_RUBY_PATH=$ruby_exec
+            break
+          fi
+        done
+        IFS=$' \t\n'
+        [[ -z $HOMEBREW_RUBY_PATH ]] && onoe "Failed to find usable Ruby $required_ruby_version!"
       fi
 
       if [[ -n "$HOMEBREW_MACOS_SYSTEM_RUBY_NEW_ENOUGH" ]]