diff --git a/extra/trees/trees-docs.factor b/extra/trees/trees-docs.factor
index 12bae4bac5..df04f1cb40 100644
--- a/extra/trees/trees-docs.factor
+++ b/extra/trees/trees-docs.factor
@@ -1,4 +1,5 @@
-USING: help.syntax help.markup trees assocs ;
+USING: help.syntax help.markup assocs ;
+IN: trees
 
 HELP: TREE{
 { $syntax "TREE{ { key value }... }" }