diff --git a/12.temporary_ins/05.coordinates-systems/20.cartesian-coordinates/10.main/textbook.en.md b/12.temporary_ins/05.coordinates-systems/20.cartesian-coordinates/10.main/textbook.en.md
index 98bc3062e..7c9dc253a 100644
--- a/12.temporary_ins/05.coordinates-systems/20.cartesian-coordinates/10.main/textbook.en.md
+++ b/12.temporary_ins/05.coordinates-systems/20.cartesian-coordinates/10.main/textbook.en.md
@@ -4,8 +4,6 @@ published: true
 routable: false
 visible: false
 lessons:
-    - slug:
-      order:
     - slug: cartesian-coordinates-linear
       order: 1
 ---