diff --git a/app/controllers/api/v1/announcements_controller.rb b/app/controllers/api/v1/announcements_controller.rb
index 1e692ff75..ee79fc19f 100644
--- a/app/controllers/api/v1/announcements_controller.rb
+++ b/app/controllers/api/v1/announcements_controller.rb
@@ -11,7 +11,7 @@ class Api::V1::AnnouncementsController < Api::BaseController
   end
 
   def dismiss
-    AnnouncementMute.create!(account: current_account, announcement: @announcement)
+    AnnouncementMute.find_or_create_by!(account: current_account, announcement: @announcement)
     render_empty
   end