3 files changed, 12 insertions, 7 deletions
diff --git a/app/models/concerns/issuable.rb b/app/models/concerns/issuable.rb
index 4db4ffb2e79..feee8460b86 100644
--- a/app/models/concerns/issuable.rb
+++ b/app/models/concerns/issuable.rb
@@ -6,8 +6,8 @@
 #
 module Issuable
   extend ActiveSupport::Concern
-  include Mentionable
   include Participable
+  include Mentionable
 
   included do
     belongs_to :author, class_name: "User"
@@ -47,7 +47,7 @@ module Issuable
              prefix: true
 
     attr_mentionable :title, :description
-    participant :author, :assignee, :notes, :mentioned_users
+    participant :author, :assignee, :notes
   end
 
   module ClassMethods
diff --git a/app/models/concerns/mentionable.rb b/app/models/concerns/mentionable.rb
index 9339ecc4bce..715fc6f689d 100644
--- a/app/models/concerns/mentionable.rb
+++ b/app/models/concerns/mentionable.rb
@@ -20,6 +20,12 @@ module Mentionable
     end
   end
 
+  included do
+    if self < Participable
+      participant ->(current_user) { mentioned_users(current_user, load_lazy_references: false) }
+    end
+  end
+
   # Returns the text used as the body of a Note when this object is referenced
   #
   # By default this will be the class name and the result of calling
diff --git a/app/models/concerns/participable.rb b/app/models/concerns/participable.rb
index 7a2bea567df..0888de62f0a 100644
--- a/app/models/concerns/participable.rb
+++ b/app/models/concerns/participable.rb
@@ -12,7 +12,7 @@
 #
 #       # ...
 #
-#       participant :author, :assignee, :mentioned_users, :notes
+#       participant :author, :assignee, :notes, ->(current_user) { mentioned_users(current_user) }
 #     end
 #
 #     issue = Issue.last
@@ -39,12 +39,11 @@ module Participable
   # Save result into variable if you are going to reuse it inside same request
   def participants(current_user = self.author, project = self.project, load_lazy_references: true)
     participants = self.class.participant_attrs.flat_map do |attr|
-      meth = method(attr)
       value =
-        if attr == :mentioned_users
-          meth.call(current_user, load_lazy_references: false)
+        if attr.respond_to?(:call)
+          instance_exec(current_user, &attr)
         else
-          meth.call
+          send(attr)
         end
 
       participants_for(value, current_user, project)