diff --git a/app/models/concerns/assignment_handler.rb b/app/models/concerns/assignment_handler.rb
index dde962ba1..9f9b7a79e 100644
--- a/app/models/concerns/assignment_handler.rb
+++ b/app/models/concerns/assignment_handler.rb
@@ -4,7 +4,7 @@ module AssignmentHandler
 
   included do
     before_save :ensure_assignee_is_from_team
-    after_commit :notify_assignment_change, :process_assignment_activities
+    after_commit :notify_assignment_change, :process_assignment_changes
   end
 
   private
@@ -36,6 +36,11 @@ module AssignmentHandler
     end
   end
 
+  def process_assignment_changes
+    process_assignment_activities
+    process_participant_assignment
+  end
+
   def process_assignment_activities
     user_name = Current.user.name if Current.user.present?
     if saved_change_to_team_id?
@@ -44,4 +49,9 @@ module AssignmentHandler
       create_assignee_change_activity(user_name)
     end
   end
+
+  def process_participant_assignment
+    return unless saved_change_to_assignee_id? && assignee_id.present?
+    self.conversation_participants.find_or_create_by!(user_id: assignee_id)
+  end
 end
diff --git a/spec/models/concerns/assignment_handler_shared.rb b/spec/models/concerns/assignment_handler_shared.rb
index 816351248..0fff7777a 100644
--- a/spec/models/concerns/assignment_handler_shared.rb
+++ b/spec/models/concerns/assignment_handler_shared.rb
@@ -85,6 +85,10 @@ shared_examples_for 'assignment_handler' do
       expect(update_assignee).to be(true)
     end
 
+    it 'adds assignee to conversation participants' do
+      expect { update_assignee }.to change { conversation.conversation_participants.count }.by(1)
+    end
+
     context 'when agent is current user' do
       before do
         Current.user = agent