diff --git a/scss/_custom-forms.scss b/scss/_custom-forms.scss
index b19e0b45eb..9088662fda 100644
--- a/scss/_custom-forms.scss
+++ b/scss/_custom-forms.scss
@@ -328,7 +328,7 @@
   &:focus {
     outline: none;
 
-    // Pseudo-elements must be split across multiple rulesets to have an affect.
+    // Pseudo-elements must be split across multiple rulesets to have an effect.
     // No box-shadow() mixin for focus accessibility.
     &::-webkit-slider-thumb { box-shadow: $custom-range-thumb-focus-box-shadow; }
     &::-moz-range-thumb     { box-shadow: $custom-range-thumb-focus-box-shadow; }