diff --git a/docs/en/02_Developer_Guides/15_Customising_the_Admin_Interface/How_Tos/Extend_CMS_Interface.md b/docs/en/02_Developer_Guides/15_Customising_the_Admin_Interface/How_Tos/Extend_CMS_Interface.md
index 024257b33..c26fd24ef 100644
--- a/docs/en/02_Developer_Guides/15_Customising_the_Admin_Interface/How_Tos/Extend_CMS_Interface.md
+++ b/docs/en/02_Developer_Guides/15_Customising_the_Admin_Interface/How_Tos/Extend_CMS_Interface.md
@@ -60,7 +60,7 @@ Load the new CSS file into the CMS, by setting the `LeftAndMain.extra_requiremen
 	:::yml
 	LeftAndMain:
 	  extra_requirements_css:
-	    - mysite/css/BookmarkedPages.css:
+	    - mysite/css/BookmarkedPages.css
 
 ## Create a "bookmark" flag on pages ##