diff --git a/bin/setup b/bin/setup
index f1a66599..4528d72c 100755
--- a/bin/setup
+++ b/bin/setup
@@ -15,7 +15,7 @@ chdir APP_ROOT do
   # Add necessary setup steps to this file.
 
   puts "== Installing dependencies =="
-  system! "gem install bundler -v 2.5.6 --conservative"
+  system! "gem install bundler -v 2.4.20 --conservative"
   system("bundle check") || system!("bundle install")
 
   # puts "\n== Copying sample files =="