diff --git a/app/controllers/epp_controller.rb b/app/controllers/epp_controller.rb
index 5c52b562a..d26cd83b5 100644
--- a/app/controllers/epp_controller.rb
+++ b/app/controllers/epp_controller.rb
@@ -119,24 +119,27 @@ class EppController < ApplicationController
   end
 
   def exactly_one_of(*selectors)
+    full_selectors = create_full_selectors(*selectors)
     return if element_count(*selectors) == 1
 
     epp_errors << {
       code: '2306',
-      msg: I18n.t(:exactly_one_parameter_required, params: selectors.join(' or '))
+      msg: I18n.t(:exactly_one_parameter_required, params: full_selectors.join(' OR '))
     }
   end
 
   def mutually_exclusive(*selectors)
+    full_selectors = create_full_selectors(*selectors)
     return if element_count(*selectors) <= 1
+
     epp_errors << {
       code: '2306',
-      msg: I18n.t(:mutally_exclusive_params, params: selectors.join(', '))
+      msg: I18n.t(:mutally_exclusive_params, params: full_selectors.join(', '))
     }
   end
 
   def optional(selector, *validations)
-    full_selector = [@prefix, selector].join(' ')
+    full_selector = [@prefix, selector].compact.join(' ')
     el = params[:parsed_frame].css(full_selector).first
     return unless el && el.text.present?
     value = el.text
@@ -151,13 +154,17 @@ class EppController < ApplicationController
   def element_count(*selectors)
     present_count = 0
     selectors.each do |selector|
-      full_selector = [@prefix, selector].join(' ')
+      full_selector = [@prefix, selector].compact.join(' ')
       el = params[:parsed_frame].css(full_selector).first
       present_count += 1 if el && el.text.present?
     end
     present_count
   end
 
+  def create_full_selectors(*selectors)
+    selectors.map { |x| [@prefix, x].compact.join(' ') }
+  end
+
   def xml_attrs_present?(ph, attributes) # TODO: THIS IS DEPRECATED AND WILL BE REMOVED IN FUTURE
     attributes.each do |x|
       epp_errors << {
diff --git a/spec/epp/domain_spec.rb b/spec/epp/domain_spec.rb
index ebc398ded..8effd8037 100644
--- a/spec/epp/domain_spec.rb
+++ b/spec/epp/domain_spec.rb
@@ -629,7 +629,7 @@ describe 'EPP Domain', epp: true do
         })
 
       response = epp_plain_request(xml, :xml)
-      response[:msg].should == 'Mutually exclusive parameters: keyData, dsData'
+      response[:msg].should == 'Mutually exclusive parameters: extension > create > keyData, extension > create > dsData'
       response[:result_code].should == '2306'
     end
   end
diff --git a/spec/epp/keyrelay_spec.rb b/spec/epp/keyrelay_spec.rb
index 5f9f36a45..256e46c1d 100644
--- a/spec/epp/keyrelay_spec.rb
+++ b/spec/epp/keyrelay_spec.rb
@@ -163,7 +163,7 @@ describe 'EPP Keyrelay', epp: true do
     })
 
     response = epp_request(xml, :xml, :elkdata)
-    response[:msg].should == 'Exactly one parameter required: expiry > relative or expiry > absolute'
+    response[:msg].should == 'Exactly one parameter required: keyrelay > expiry > relative OR keyrelay > expiry > absolute'
 
     @zone.messages.queued.count.should == msg_count
   end