1 files changed, 10 insertions, 9 deletions
diff --git a/stdlib/source/library/lux/data/collection/tree/finger.lux b/stdlib/source/library/lux/data/collection/tree/finger.lux
index b0dcece05..3f807f49f 100644
--- a/stdlib/source/library/lux/data/collection/tree/finger.lux
+++ b/stdlib/source/library/lux/data/collection/tree/finger.lux
@@ -20,15 +20,16 @@
     #root (Or v
               [(Tree @ t v) (Tree @ t v)])})
 
-  (interface: .public (Builder @ t)
-    (: (All [v]
-         (-> t v (Tree @ t v)))
-       leaf)
-    (: (All [v]
-         (-> (Tree @ t v)
-             (Tree @ t v)
-             (Tree @ t v)))
-       branch))
+  (type: .public (Builder @ t)
+    (Interface
+     (: (All [v]
+          (-> t v (Tree @ t v)))
+        leaf)
+     (: (All [v]
+          (-> (Tree @ t v)
+              (Tree @ t v)
+              (Tree @ t v)))
+        branch)))
 
   (template [<name> <tag> <output>]
     [(def: .public <name>