diff --git a/css/css-contain/contain-style-counters-004.html b/css/css-contain/contain-style-counters-004.html
index 40d68b4641e56a..56e7e3d87e76ed 100644
--- a/css/css-contain/contain-style-counters-004.html
+++ b/css/css-contain/contain-style-counters-004.html
@@ -1,71 +1,32 @@
 <!DOCTYPE html>
-
-  <meta charset="UTF-8">
-
-  <title>CSS Containment Test: 'contain: style' for counters (span descendants of &lt;body&gt;)</title>
-
-  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
-  <link rel="help" href="https://www.w3.org/TR/css-contain-1/#containment-style">
-  <link rel="match" href="reference/contain-style-counters-004-ref.html">
-
-
-  <style>
-  body
-    {
-      counter-reset: counter-of-span 13;
-    }
-
-    /*
-    This creates a new counter identified as "counter-of-span"
-    and initially sets such counter to 13 (an entirely
-    arbitrary number)
-    */
-
-  body
-    {
-      contain: style;
-    }
-
-    /*
-    This will reset the counter to 0.
-    */
-
-  body span
-    {
-      counter-increment: counter-of-span 5;
-    }
-
-    /*
-    This increments the counter identified as "counter-of-span"
-    of the step value of 5 (an entirely arbitrary number) each
-    and every time there is a <span> descendant within the subtree
-    of body
-    */
-
-  div
-    {
-      font-size: 3em;
-    }
-
-  div::after
-    {
-      content: counter(counter-of-span);
-    }
-
-    /*
-    Now, the generated content after the span is set to the
-    current value of the counter identified as "counter-of-span"
-    */
-  </style>
-
-  <body>
-
-  <p> <span></span> <span></span> <span></span> <span></span>
-
-  <!-- 4 span inside the <p>. However, since div isn't a sibling of spans,
-       it creates a new counter.
-  -->
-
-  <p>Test passes if there is the number 0.
-
+<meta charset="UTF-8">
+<title>CSS Containment Test: 'contain: style' for counters (span descendants of &lt;body&gt;)</title>
+<link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+<link rel="help" href="https://www.w3.org/TR/css-contain-1/#containment-style">
+<link rel="match" href="reference/contain-style-counters-004-ref.html">
+<style>
+body {
+  counter-reset: counter-of-span 13;
+  contain: style;
+}
+body span {
+  counter-increment: counter-of-span 5;
+}
+div {
+  font-size: 3em;
+}
+div::after {
+  content: counter(counter-of-span);
+}
+</style>
+<body>
+  <p><span></span> <span></span> <span></span> <span></span></p>
+
+<!-- The <span>s aren't allowed to modify the counter instantiated on the <body>,
+       so a new instance of the counter is created.
+       Since the <div> isn't a sibling of the <span>, it will not inherit this new instance,
+       and instead it will read the original counter from the <body>, with value 13.
+       This is per example at: https://drafts.csswg.org/css-contain/#containment-style  -->
+  <p>Test passes if there is the number 13.</p>
   <div></div>
+</body>
diff --git a/css/css-contain/reference/contain-style-counters-004-ref.html b/css/css-contain/reference/contain-style-counters-004-ref.html
index afe60666c02e72..c362dbbf5330f1 100644
--- a/css/css-contain/reference/contain-style-counters-004-ref.html
+++ b/css/css-contain/reference/contain-style-counters-004-ref.html
@@ -13,6 +13,6 @@
     }
   </style>
 
-  <p>Test passes if there is the number 0.
+  <p>Test passes if there is the number 13.
 
-  <div>0</div>
+  <div>13</div>
