diff --git a/app/lib/activitypub/activity/create.rb b/app/lib/activitypub/activity/create.rb
index cc2536578f..2cc6be4d75 100644
--- a/app/lib/activitypub/activity/create.rb
+++ b/app/lib/activitypub/activity/create.rb
@@ -529,7 +529,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   end
 
   def instance_info
-    @instance_info ||= InstanceInfo.find_by(@account.domain)
+    @instance_info ||= InstanceInfo.find_by(domain: @account.domain)
   end
 
   def misskey_software?
diff --git a/app/services/activitypub/process_account_service.rb b/app/services/activitypub/process_account_service.rb
index 18af495e35..eb986fc88e 100644
--- a/app/services/activitypub/process_account_service.rb
+++ b/app/services/activitypub/process_account_service.rb
@@ -294,7 +294,7 @@ class ActivityPub::ProcessAccountService < BaseService
   end
 
   def instance_info
-    @instance_info ||= InstanceInfo.find_by(@domain)
+    @instance_info ||= InstanceInfo.find_by(domain: @domain)
   end
 
   def misskey_software?