diff --git a/lib/telegram/bot/middleware.rb b/lib/telegram/bot/middleware.rb
index e42b9d4..087069c 100644
--- a/lib/telegram/bot/middleware.rb
+++ b/lib/telegram/bot/middleware.rb
@@ -15,7 +15,7 @@ module Telegram
       def call(env)
         update = env['action_dispatch.request.request_parameters']
         controller.dispatch(bot, update)
-        [200, {}, '']
+        [200, {}, ['']]
       end
 
       def inspect
diff --git a/lib/telegram/bot/version.rb b/lib/telegram/bot/version.rb
index 8e3a1ca..939d685 100644
--- a/lib/telegram/bot/version.rb
+++ b/lib/telegram/bot/version.rb
@@ -1,6 +1,6 @@
 module Telegram
   module Bot
-    VERSION = '0.4.1'.freeze
+    VERSION = '0.4.2'.freeze
 
     def self.gem_version
       Gem::Version.new VERSION
diff --git a/spec/telegram/bot/middleware_spec.rb b/spec/telegram/bot/middleware_spec.rb
index a4c62c5..ab4b605 100644
--- a/spec/telegram/bot/middleware_spec.rb
+++ b/spec/telegram/bot/middleware_spec.rb
@@ -13,6 +13,6 @@ RSpec.describe Telegram::Bot::Middleware do
       subject
     end
 
-    it { should eq [200, {}, ''] }
+    it { should eq [200, {}, ['']] }
   end
 end