diff --git a/app/serializers/rest/instance_serializer.rb b/app/serializers/rest/instance_serializer.rb
index e8b90d85df..aed2ac476f 100644
--- a/app/serializers/rest/instance_serializer.rb
+++ b/app/serializers/rest/instance_serializer.rb
@@ -78,6 +78,10 @@ class REST::InstanceSerializer < ActiveModel::Serializer
       translation: {
         enabled: TranslationService.configured?,
       },
+
+      reactions: {
+        max_reactions: StatusReactionValidator::LIMIT,
+      },
     }
   end
 
diff --git a/app/serializers/rest/v1/instance_serializer.rb b/app/serializers/rest/v1/instance_serializer.rb
index 0c21014046..4b3e2b86d9 100644
--- a/app/serializers/rest/v1/instance_serializer.rb
+++ b/app/serializers/rest/v1/instance_serializer.rb
@@ -97,6 +97,10 @@ class REST::V1::InstanceSerializer < ActiveModel::Serializer
         min_expiration: PollValidator::MIN_EXPIRATION,
         max_expiration: PollValidator::MAX_EXPIRATION,
       },
+
+      reactions: {
+        max_reactions: StatusReactionValidator::LIMIT,
+      },
     }
   end