diff --git a/app.json b/app.json
index 64edc4a81..055235032 100644
--- a/app.json
+++ b/app.json
@@ -48,6 +48,7 @@
       "size": "FREE"
     }
   },
+  "stack": "heroku-20",
   "image": "heroku/ruby",
   "addons": [ "heroku-redis", "heroku-postgresql"],
   "buildpacks": [
diff --git a/db/schema.rb b/db/schema.rb
index b928a570d..6b41fc443 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -395,7 +395,7 @@ ActiveRecord::Schema.define(version: 2022_08_09_104508) do
     t.datetime "agent_last_seen_at"
     t.jsonb "additional_attributes", default: {}
     t.bigint "contact_inbox_id"
-    t.uuid "uuid", default: -> { "public.gen_random_uuid()" }, null: false
+    t.uuid "uuid", default: -> { "gen_random_uuid()" }, null: false
     t.string "identifier"
     t.datetime "last_activity_at", default: -> { "CURRENT_TIMESTAMP" }, null: false
     t.bigint "team_id"