diff --git a/.travis.yml b/.travis.yml
index f3fd9b7..6ba07c2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 language: ruby
 rvm:
-  - 2.2.3
+  - 2.6.0
 services:
   - memcached
 script:
diff --git a/spec/controller_helpers_spec.rb b/spec/controller_helpers_spec.rb
index 995c403..e1fb790 100644
--- a/spec/controller_helpers_spec.rb
+++ b/spec/controller_helpers_spec.rb
@@ -31,7 +31,8 @@ describe RuCaptcha do
 
   describe '.rucaptcha_sesion_key_key' do
     it 'should work' do
-      expect(simple.rucaptcha_sesion_key_key).to eq ['rucaptcha-session', simple.session.id].join(':')
+      session_id_digest = Digest::SHA256.hexdigest(simple.session.id.inspect)
+      expect(simple.rucaptcha_sesion_key_key).to eq ['rucaptcha-session', session_id_digest].join(':')
     end
   end