diff --git a/package/govuk/components/checkboxes/fixtures.json b/package/govuk/components/checkboxes/fixtures.json
index dc1c0f683d..795f12935c 100644
--- a/package/govuk/components/checkboxes/fixtures.json
+++ b/package/govuk/components/checkboxes/fixtures.json
@@ -181,6 +181,7 @@
                 "fieldset": {
                     "legend": {
                         "text": "How do you want to sign in?",
+                        "classes": "govuk-fieldset__legend--l",
                         "isPageHeading": true
                     }
                 },
@@ -206,7 +207,7 @@
                     }
                 ]
             },
-            "html": "<div class=\"govuk-form-group\">\n\n  <fieldset class=\"govuk-fieldset\">\n  \n  <legend class=\"govuk-fieldset__legend\">\n  \n    <h1 class=\"govuk-fieldset__heading\">\n      How do you want to sign in?\n    </h1>\n  \n  </legend>\n  \n\n  <div class=\"govuk-checkboxes\"\n    data-module=\"govuk-checkboxes\">\n    \n      \n        \n          \n          \n          \n          \n          <div class=\"govuk-checkboxes__item\">\n            <input class=\"govuk-checkboxes__input\" id=\"government-gateway\" name=\"gateway\" type=\"checkbox\" value=\"gov-gateway\" aria-describedby=\"government-gateway-item-hint\">\n            <label class=\"govuk-label govuk-checkboxes__label\" for=\"government-gateway\">\n        Sign in with Government Gateway\n      </label>\n            \n            <div id=\"government-gateway-item-hint\" class=\"govuk-hint govuk-checkboxes__hint\">\n        You&#39;ll have a user ID if you&#39;ve registered for Self Assessment or filed a tax return online before.\n      </div>\n            \n          </div>\n          \n        \n      \n    \n      \n        \n          \n          \n          \n          \n          <div class=\"govuk-checkboxes__item\">\n            <input class=\"govuk-checkboxes__input\" id=\"govuk-verify\" name=\"verify\" type=\"checkbox\" value=\"gov-verify\" disabled aria-describedby=\"govuk-verify-item-hint\">\n            <label class=\"govuk-label govuk-checkboxes__label\" for=\"govuk-verify\">\n        Sign in with GOV.UK Verify\n      </label>\n            \n            <div id=\"govuk-verify-item-hint\" class=\"govuk-hint govuk-checkboxes__hint\">\n        You&#39;ll have an account if you&#39;ve already proved your identity with either Barclays, CitizenSafe, Digidentity, Experian, Post Office, Royal Mail or SecureIdentity.\n      </div>\n            \n          </div>\n          \n        \n      \n    \n  </div>\n  \n\n</fieldset>\n\n\n</div>",
+            "html": "<div class=\"govuk-form-group\">\n\n  <fieldset class=\"govuk-fieldset\">\n  \n  <legend class=\"govuk-fieldset__legend govuk-fieldset__legend--l\">\n  \n    <h1 class=\"govuk-fieldset__heading\">\n      How do you want to sign in?\n    </h1>\n  \n  </legend>\n  \n\n  <div class=\"govuk-checkboxes\"\n    data-module=\"govuk-checkboxes\">\n    \n      \n        \n          \n          \n          \n          \n          <div class=\"govuk-checkboxes__item\">\n            <input class=\"govuk-checkboxes__input\" id=\"government-gateway\" name=\"gateway\" type=\"checkbox\" value=\"gov-gateway\" aria-describedby=\"government-gateway-item-hint\">\n            <label class=\"govuk-label govuk-checkboxes__label\" for=\"government-gateway\">\n        Sign in with Government Gateway\n      </label>\n            \n            <div id=\"government-gateway-item-hint\" class=\"govuk-hint govuk-checkboxes__hint\">\n        You&#39;ll have a user ID if you&#39;ve registered for Self Assessment or filed a tax return online before.\n      </div>\n            \n          </div>\n          \n        \n      \n    \n      \n        \n          \n          \n          \n          \n          <div class=\"govuk-checkboxes__item\">\n            <input class=\"govuk-checkboxes__input\" id=\"govuk-verify\" name=\"verify\" type=\"checkbox\" value=\"gov-verify\" disabled aria-describedby=\"govuk-verify-item-hint\">\n            <label class=\"govuk-label govuk-checkboxes__label\" for=\"govuk-verify\">\n        Sign in with GOV.UK Verify\n      </label>\n            \n            <div id=\"govuk-verify-item-hint\" class=\"govuk-hint govuk-checkboxes__hint\">\n        You&#39;ll have an account if you&#39;ve already proved your identity with either Barclays, CitizenSafe, Digidentity, Experian, Post Office, Royal Mail or SecureIdentity.\n      </div>\n            \n          </div>\n          \n        \n      \n    \n  </div>\n  \n\n</fieldset>\n\n\n</div>",
             "hidden": false
         },
         {
diff --git a/package/govuk/components/radios/fixtures.json b/package/govuk/components/radios/fixtures.json
index ab5abc2bd5..5eebe18f30 100644
--- a/package/govuk/components/radios/fixtures.json
+++ b/package/govuk/components/radios/fixtures.json
@@ -60,6 +60,7 @@
                 "fieldset": {
                     "legend": {
                         "text": "How do you want to sign in?",
+                        "classes": "govuk-fieldset__legend--l",
                         "isPageHeading": true
                     }
                 },
@@ -83,7 +84,7 @@
                     }
                 ]
             },
-            "html": "<div class=\"govuk-form-group\">\n\n  <fieldset class=\"govuk-fieldset\">\n  \n  <legend class=\"govuk-fieldset__legend\">\n  \n    <h1 class=\"govuk-fieldset__heading\">\n      How do you want to sign in?\n    </h1>\n  \n  </legend>\n  \n\n  <div class=\"govuk-radios\"\n    data-module=\"govuk-radios\">\n    \n      \n        \n        \n        <div class=\"govuk-radios__item\">\n          <input class=\"govuk-radios__input\" id=\"gateway\" name=\"gov\" type=\"radio\" value=\"gateway\" aria-describedby=\"gateway-item-hint\">\n          <label class=\"govuk-label govuk-radios__label\" for=\"gateway\">\n        Sign in with Government Gateway\n      </label>\n          \n          <div id=\"gateway-item-hint\" class=\"govuk-hint govuk-radios__hint\">\n        You’ll have a user ID if you’ve registered for Self Assessment or filed a tax return online before.\n      </div>\n          \n        </div>\n        \n        \n      \n    \n      \n        \n        \n        <div class=\"govuk-radios__item\">\n          <input class=\"govuk-radios__input\" id=\"verify\" name=\"gov\" type=\"radio\" value=\"verify\" disabled aria-describedby=\"verify-item-hint\">\n          <label class=\"govuk-label govuk-radios__label\" for=\"verify\">\n        Sign in with GOV.UK Verify\n      </label>\n          \n          <div id=\"verify-item-hint\" class=\"govuk-hint govuk-radios__hint\">\n        You’ll have an account if you’ve already proved your identity with either Barclays, CitizenSafe, Digidentity, Experian, Post Office, Royal Mail or SecureIdentity.\n      </div>\n          \n        </div>\n        \n        \n      \n    \n  </div>\n  \n\n</fieldset>\n\n\n</div>",
+            "html": "<div class=\"govuk-form-group\">\n\n  <fieldset class=\"govuk-fieldset\">\n  \n  <legend class=\"govuk-fieldset__legend govuk-fieldset__legend--l\">\n  \n    <h1 class=\"govuk-fieldset__heading\">\n      How do you want to sign in?\n    </h1>\n  \n  </legend>\n  \n\n  <div class=\"govuk-radios\"\n    data-module=\"govuk-radios\">\n    \n      \n        \n        \n        <div class=\"govuk-radios__item\">\n          <input class=\"govuk-radios__input\" id=\"gateway\" name=\"gov\" type=\"radio\" value=\"gateway\" aria-describedby=\"gateway-item-hint\">\n          <label class=\"govuk-label govuk-radios__label\" for=\"gateway\">\n        Sign in with Government Gateway\n      </label>\n          \n          <div id=\"gateway-item-hint\" class=\"govuk-hint govuk-radios__hint\">\n        You’ll have a user ID if you’ve registered for Self Assessment or filed a tax return online before.\n      </div>\n          \n        </div>\n        \n        \n      \n    \n      \n        \n        \n        <div class=\"govuk-radios__item\">\n          <input class=\"govuk-radios__input\" id=\"verify\" name=\"gov\" type=\"radio\" value=\"verify\" disabled aria-describedby=\"verify-item-hint\">\n          <label class=\"govuk-label govuk-radios__label\" for=\"verify\">\n        Sign in with GOV.UK Verify\n      </label>\n          \n          <div id=\"verify-item-hint\" class=\"govuk-hint govuk-radios__hint\">\n        You’ll have an account if you’ve already proved your identity with either Barclays, CitizenSafe, Digidentity, Experian, Post Office, Royal Mail or SecureIdentity.\n      </div>\n          \n        </div>\n        \n        \n      \n    \n  </div>\n  \n\n</fieldset>\n\n\n</div>",
             "hidden": false
         },
         {