diff --git a/manifest.toml b/manifest.toml
index 06376f1..5aac5cb 100644
--- a/manifest.toml
+++ b/manifest.toml
@@ -48,10 +48,9 @@ ram.runtime = "50M"
     [resources.apt]
     packages = "postgresql"
 
-    [[resources.apt.extras]]
-    repo = "deb https://dl.yarnpkg.com/debian/ stable main"
-    key = "https://dl.yarnpkg.com/debian/pubkey.gpg"
-    packages = "yarn"
+    extras.yarn.repo = "deb https://dl.yarnpkg.com/debian/ stable main"
+    extras.yarn.key = "https://dl.yarnpkg.com/debian/pubkey.gpg"
+    extras.yarn.packages = "yarn"
 
     [resources.database]
     type = "postgresql"