diff --git a/css.html b/css.html
index 692ae38ae8..f1679c703c 100644
--- a/css.html
+++ b/css.html
@@ -1567,7 +1567,7 @@ For example, <code>&lt;section&gt;</code> should be wrapped as inline.
 
 
     <h2 id="forms-inline">Inline form</h2>
-    <p>Add <code>.form-inline</code> for left-aligned and inline-block controls for a compact layout.</p>
+    <p>Add <code>.form-inline</code> to your <code>&lt;form&gt;</code> for left-aligned and inline-block controls. <strong>This only applies to forms within viewports that are at least 768px wide.</strong></p>
     <div class="bs-callout bs-callout-danger">
       <h4>Requires custom widths</h4>
       <p>Inputs, selects, and textareas are 100% wide by default in Bootstrap. To use the inline form, you'll have to set a width on the form controls used within.</p>