diff --git a/README.markdown b/README.markdown
index b4c4f11..623c8cd 100644
--- a/README.markdown
+++ b/README.markdown
@@ -49,7 +49,8 @@ At any time, configuration can be modified with `Ipizza::Config.configure` block
       # Path to bank's public key file. Can be specified
       # relatively to YAML file
       file_cert: ./certificates/bank_public.crt
-      snd_id: dealer
+      snd_id: merchant
+      rec_id: bank
       encoding: UTF-8
 
 ## Payment requests
diff --git a/lib/ipizza/provider/base.rb b/lib/ipizza/provider/base.rb
index 9b97cce..4cf36c7 100644
--- a/lib/ipizza/provider/base.rb
+++ b/lib/ipizza/provider/base.rb
@@ -60,7 +60,7 @@ def authentication_request(service_no = 4011, param = {})
       when '4011'
         req.sign_params['VK_REPLY'] = '3012'
       when '4012'
-        req.sign_params.merge(
+        req.sign_params.merge!(
           'VK_REC_ID' => self.class.rec_id,
           'VK_NONCE' => param[:vk_nonce]
         )