diff --git a/lib/govuk_tech_docs/warning_text_extension.rb b/lib/govuk_tech_docs/warning_text_extension.rb
index 63030691..055782e4 100644
--- a/lib/govuk_tech_docs/warning_text_extension.rb
+++ b/lib/govuk_tech_docs/warning_text_extension.rb
@@ -10,7 +10,7 @@ def warning_text(text)
         <div class="govuk-warning-text">
           <span class="govuk-warning-text__icon" aria-hidden="true">!</span>
           <strong class="govuk-warning-text__text">
-            <span class="govuk-warning-text__assistive">Warning</span>
+            <span class="govuk-visually-hidden">Warning</span>
             #{text}
           </strong>
         </div>