diff --git a/test/unit/lib/redmine/wiki_formatting/common_mark/formatter_test.rb b/test/unit/lib/redmine/wiki_formatting/common_mark/formatter_test.rb
index 948981e70..6ef7f9d14 100644
--- a/test/unit/lib/redmine/wiki_formatting/common_mark/formatter_test.rb
+++ b/test/unit/lib/redmine/wiki_formatting/common_mark/formatter_test.rb
@@ -208,6 +208,75 @@ EXPECTED
       @formatter.new(text).update_section(3, replacement)
   end
 
+  STR_SETEXT_LIKE = [
+    # 0
+    <<~STR.chomp,
+      # Title
+    STR
+    # 1
+    <<~STR.chomp,
+      ## Heading 2
+
+      Thematic breaks - not be confused with setext headings.
+
+      ---
+
+      Preceding CRLF is the default for web-submitted data.
+      \r
+      ---\r
+      \r
+
+      A space-only line does not mean much.
+      \s
+      ---
+
+      End of thematic breaks.
+    STR
+    # 2
+    <<~STR.chomp,
+      ## Heading 2
+      Nulla nunc nisi, egestas in ornare vel, posuere ac libero.
+    STR
+  ]
+
+  STR_RARE_SETEXT_LIKE = [
+    # 0
+    <<~STR.chomp,
+      # Title
+    STR
+    # 1
+    <<~STR.chomp,
+      ## Heading 2
+
+      - item
+      one
+      -
+      not a heading
+    STR
+    # 2
+    <<~STR.chomp,
+      ## Heading 2
+      Nulla nunc nisi, egestas in ornare vel, posuere ac libero.
+    STR
+  ]
+
+  def test_get_section_should_ignore_setext_like_text
+    text = STR_SETEXT_LIKE.join("\n\n")
+    assert_section_with_hash STR_SETEXT_LIKE[1], text, 2
+    assert_section_with_hash STR_SETEXT_LIKE[2], text, 3
+  end
+
+  def test_get_section_should_ignore_rare_setext_like_text
+    begin
+      text = STR_RARE_SETEXT_LIKE.join("\n\n")
+      assert_section_with_hash STR_RARE_SETEXT_LIKE[1], text, 2
+      assert_section_with_hash STR_RARE_SETEXT_LIKE[2], text, 3
+    rescue Minitest::Assertion => e
+      skip "Section extraction is currently limited, see #35037. Known error: #{e.message}"
+    end
+    refute "This test should be adjusted when fixing the known error."
+  end
+
   def test_should_emphasize_text
     text = 'This _text_ should be emphasized'
     assert_equal '<p>This <em>text</em> should be emphasized</p>', format(text)