diff --git a/app/lib/activitypub/activity/create.rb b/app/lib/activitypub/activity/create.rb
index 85195f4c395..d6516a98f62 100644
--- a/app/lib/activitypub/activity/create.rb
+++ b/app/lib/activitypub/activity/create.rb
@@ -82,6 +82,9 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     process_tags
     process_audience
 
+    # Reject the status unless all the hashtags are usable:
+    return reject_payload! unless @tags.all?(&:usable?)
+
     ApplicationRecord.transaction do
       @status = Status.create!(@params)
       attach_tags(@status)