diff --git a/app/assets/stylesheets/zammad.scss b/app/assets/stylesheets/zammad.scss
index 74603a465..d132262e3 100644
--- a/app/assets/stylesheets/zammad.scss
+++ b/app/assets/stylesheets/zammad.scss
@@ -4295,7 +4295,7 @@ footer {
 
 .tabsSidebar-sidebarSpacer {
   margin-right: $sidebarWidth;
-  transition: marginRight 500ms;
+  transition: margin-right 500ms;
 }
 
 .tabsSidebar-sidebarSpacer.is-closed {