diff --git a/docs/customize.html b/docs/customize.html
index 7ba9eb8e03..f41e0f1e07 100644
--- a/docs/customize.html
+++ b/docs/customize.html
@@ -25,6 +25,11 @@ lead: Customize Bootstrap's components, Less variables, and jQuery plugins to ge
 
 <!-- Customizer form -->
 
+<div id="defaults-change-alert" class="alert alert-warning alert-dismissible" role="alert">
+  <button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">&times;</span></button>
+  <strong>Heads up!</strong> The default value for <code>@brand-primary</code> has changed in the latest release to improve contrast and accessibility. Please double check your compiled CSS when upgrading.
+</div>
+
 <div class="bs-docs-section bs-customizer-import">
   <div id="import-drop-target" class="bs-dropzone">
     <h2>✍</h2>