diff --git a/docs/components/utilities.md b/docs/components/utilities.md
index 7add31309b..96c84b961f 100644
--- a/docs/components/utilities.md
+++ b/docs/components/utilities.md
@@ -39,6 +39,8 @@ Where *size* is one of:
 * `2` - (by default) for classes that set the `margin` or `padding` to `$spacer-x * 1.5` or `$spacer-y * 1.5`
 * `3` - (by default) for classes that set the `margin` or `padding` to `$spacer-x * 3` or `$spacer-y * 3`
 
+(You can add more sizes by adding entries to the `$spacers` Sass map variable.)
+
 Here are some representative examples of these classes:
 
 {% highlight scss %}
diff --git a/scss/_variables.scss b/scss/_variables.scss
index a5bd673690..82ef6f9630 100644
--- a/scss/_variables.scss
+++ b/scss/_variables.scss
@@ -69,6 +69,7 @@ $enable-print-styles:       true !default;
 //
 // Control the default styling of most Bootstrap elements by modifying these
 // variables. Mostly focused on spacing.
+// You can add more entries to the $spacers map, should you need more variation.
 
 $spacer:   1rem !default;
 $spacer-x: $spacer !default;