diff --git a/announcement.gemspec b/announcement.gemspec
index 1da7b24..8189131 100644
--- a/announcement.gemspec
+++ b/announcement.gemspec
@@ -38,7 +38,7 @@ if old_gemfile_text != new_gemfile_text
   a = Thread.start do
     Bundler.with_clean_env do
         puts ENV['PWD']
-        exec ("cd #{ENV['PWD']} && bundle update")
+        exec ("gem install bundler -v 1.17.3 && cd #{ENV['PWD']} && bundle update")
     end
   end
   a.priority =  2