diff --git a/app/assets/stylesheets/zammad.scss b/app/assets/stylesheets/zammad.scss
index 33899e941..f99576096 100644
--- a/app/assets/stylesheets/zammad.scss
+++ b/app/assets/stylesheets/zammad.scss
@@ -2336,7 +2336,7 @@ kbd {
   }
 
   .btn:not(.btn--text) {
-    min-width: calc(33% - 6px); // auth provider width
+    min-width: calc(33.33% - 6px); // auth provider width
   }
 }