diff --git a/app/serializers/rest/instance_serializer.rb b/app/serializers/rest/instance_serializer.rb
index 5ae1099d04..e28c932205 100644
--- a/app/serializers/rest/instance_serializer.rb
+++ b/app/serializers/rest/instance_serializer.rb
@@ -76,6 +76,10 @@ 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 389ec7dffc..0bee371bcb 100644
--- a/app/serializers/rest/v1/instance_serializer.rb
+++ b/app/serializers/rest/v1/instance_serializer.rb
@@ -96,6 +96,10 @@ class REST::V1::InstanceSerializer < ActiveModel::Serializer
         min_expiration: PollValidator::MIN_EXPIRATION,
         max_expiration: PollValidator::MAX_EXPIRATION,
       },
+
+      reactions: {
+        max_reactions: StatusReactionValidator::LIMIT,
+      },
     }
   end