diff --git a/12.temporary_ins/05.coordinates-systems/30.cylindrical-coordinates/10.main/textbook.fr.md b/12.temporary_ins/05.coordinates-systems/30.cylindrical-coordinates/10.main/textbook.fr.md
index c7a795445..60d6b11fb 100644
--- a/12.temporary_ins/05.coordinates-systems/30.cylindrical-coordinates/10.main/textbook.fr.md
+++ b/12.temporary_ins/05.coordinates-systems/30.cylindrical-coordinates/10.main/textbook.fr.md
@@ -8,7 +8,7 @@ lessons:
       order:
     - slug: cylindrical-coordinates-linear
       order: 1 
-    - slug: cylindrical-coordinates-exchange-FR_ES
+    - slug: cylindrical-coordinates-exchange-FR-ES
       order: 1
 ---