diff --git a/scss/_variables.scss b/scss/_variables.scss
index f0949eaffe..21c96b5d24 100644
--- a/scss/_variables.scss
+++ b/scss/_variables.scss
@@ -189,6 +189,7 @@ $grid-breakpoints: (
 // Define the maximum width of `.container` for different screen sizes.
 
 $container-max-widths: (
+  xs: 100%,
   sm: 540px,
   md: 720px,
   lg: 960px,