diff --git a/flake.nix b/flake.nix
index 057a196..0348cba 100644
--- a/flake.nix
+++ b/flake.nix
@@ -58,7 +58,8 @@
       latest-modified-timestamp = head
         (sort (a: b: a > b)
           (filter (timestamp: timestamp != null)
-            (map (input: toInt input.lastModifiedDate) inputs)));
+            (map (input: toInt input.lastModifiedDate)
+              (attrValues inputs))));
 
       concat-timestamp = timestamp:
         toInt (substring 0 10 (toString timestamp));