diff --git a/wagtail/admin/tests/test_pages_views.py b/wagtail/admin/tests/test_pages_views.py
index 32354063c..4945e8610 100644
--- a/wagtail/admin/tests/test_pages_views.py
+++ b/wagtail/admin/tests/test_pages_views.py
@@ -4868,7 +4868,7 @@ class TestInlineStreamField(TestCase, WagtailTestUtils):
         self.assertEqual(response.status_code, 200)
 
         # response should include HTML declarations for streamfield child blocks
-        self.assertContains(response, '<li id="__PREFIX__-container" class="sequence-member">')
+        self.assertContains(response, '<div id="__PREFIX__-container" aria-hidden="false">')
 
 
 class TestRecentEditsPanel(TestCase, WagtailTestUtils):
diff --git a/wagtail/core/tests/test_blocks.py b/wagtail/core/tests/test_blocks.py
index 41e55817e..7ab2a507a 100644
--- a/wagtail/core/tests/test_blocks.py
+++ b/wagtail/core/tests/test_blocks.py
@@ -1200,7 +1200,7 @@ class TestStructBlock(SimpleTestCase):
 
         self.assertIn('<div class="struct-block">', html)
         self.assertIn('<div class="field char_field widget-text_input fieldname-title">', html)
-        self.assertIn('<label for="mylink-title">Title:</label>', html)
+        self.assertIn('<label class="field__label" for="mylink-title">Title</label>', html)
         self.assertInHTML(
             '<input id="mylink-title" name="mylink-title" placeholder="Title" type="text" value="Wagtail site" />', html
         )
@@ -1225,7 +1225,7 @@ class TestStructBlock(SimpleTestCase):
             'link': 'http://www.wagtail.io',
         }), prefix='mylink')
 
-        self.assertIn('<li class="required">', html)
+        self.assertIn('<div class="field required">', html)
 
     def test_render_form_unknown_field(self):
         class LinkBlock(blocks.StructBlock):
@@ -1290,7 +1290,7 @@ class TestStructBlock(SimpleTestCase):
             'link': 'http://www.wagtail.io',
         }), prefix='mylink')
 
-        self.assertIn('<div class="sequence-member__help help"><span class="icon-help-inverse" aria-hidden="true"></span>Self-promotion is encouraged</div>', html)
+        self.assertInHTML('<div class="help"><span class="icon-help-inverse" aria-hidden="true"></span> Self-promotion is encouraged</div>', html)
 
         # check it can be overridden in the block constructor
         block = LinkBlock(help_text="Self-promotion is discouraged")
@@ -1299,7 +1299,7 @@ class TestStructBlock(SimpleTestCase):
             'link': 'http://www.wagtail.io',
         }), prefix='mylink')
 
-        self.assertIn('<div class="sequence-member__help help"><span class="icon-help-inverse" aria-hidden="true"></span>Self-promotion is discouraged</div>', html)
+        self.assertInHTML('<div class="help"><span class="icon-help-inverse" aria-hidden="true"></span> Self-promotion is discouraged</div>', html)
 
     def test_media_inheritance(self):
         class ScriptedCharBlock(blocks.CharBlock):
@@ -1734,7 +1734,7 @@ class TestListBlock(WagtailTestUtils, SimpleTestCase):
     def test_render_form_wrapper_class(self):
         html = self.render_form()
 
-        self.assertIn('<div class="sequence-container sequence-type-list">', html)
+        self.assertIn('<div class="c-sf-container">', html)
 
     def test_render_form_count_field(self):
         html = self.render_form()
@@ -1755,8 +1755,8 @@ class TestListBlock(WagtailTestUtils, SimpleTestCase):
     def test_render_form_labels(self):
         html = self.render_form()
 
-        self.assertIn('<label for="links-0-value-title">Title:</label>', html)
-        self.assertIn('<label for="links-0-value-link">Link:</label>', html)
+        self.assertIn('<label class="field__label" for="links-0-value-title">Title</label>', html)
+        self.assertIn('<label class="field__label" for="links-0-value-link">Link</label>', html)
 
     def test_render_form_values(self):
         html = self.render_form()
@@ -2231,7 +2231,7 @@ class TestStreamBlock(WagtailTestUtils, SimpleTestCase):
     def test_render_form_wrapper_class(self):
         html = self.render_form()
 
-        self.assertIn('<div class="sequence-container sequence-type-stream">', html)
+        self.assertIn('<div class="c-sf-container">', html)
 
     def test_render_form_count_field(self):
         html = self.render_form()
@@ -2662,7 +2662,7 @@ class TestStreamBlock(WagtailTestUtils, SimpleTestCase):
         self.assertTrue(value1 != value3)
 
     def test_render_considers_group_attribute(self):
-        """If group attributes are set in Block Meta classes, render a <h3> for each different block"""
+        """If group attributes are set in Block Meta classes, render a <h4> for each different block"""
 
         class Group1Block1(blocks.CharBlock):
             class Meta:
@@ -2691,9 +2691,9 @@ class TestStreamBlock(WagtailTestUtils, SimpleTestCase):
             ('ngb', NoGroupBlock()),
         ])
         html = block.render_form('')
-        self.assertNotIn('<h3></h3>', block.render_form(''))
-        self.assertIn('<h3>group1</h3>', html)
-        self.assertIn('<h3>group2</h3>', html)
+        self.assertNotIn('<h4 class="c-sf-add-panel__group-title"></h4>', block.render_form(''))
+        self.assertIn('<h4 class="c-sf-add-panel__group-title">group1</h4>', html)
+        self.assertIn('<h4 class="c-sf-add-panel__group-title">group2</h4>', html)
 
     def test_value_from_datadict(self):
         class ArticleBlock(blocks.StreamBlock):