diff --git a/src/rules.ts b/src/rules.ts
index 14fd0a9cf7..cd6baf909e 100644
--- a/src/rules.ts
+++ b/src/rules.ts
@@ -12,8 +12,13 @@ const fences = /^ {0,3}(`{3,}(?=[^`\n]*(?:\n|$))|~{3,})([^\n]*)(?:\n|$)(?:|([\s\
const hr = /^ {0,3}((?:-[\t ]*){3,}|(?:_[ \t]*){3,}|(?:\*[ \t]*){3,})(?:\n+|$)/;
const heading = /^ {0,3}(#{1,6})(?=\s|$)(.*)(?:\n+|$)/;
const bullet = /(?:[*+-]|\d{1,9}[.)])/;
-const lheading = edit(/^(?!bull )((?:.|\n(?!\s*?\n|bull ))+?)\n {0,3}(=+|-+) *(?:\n+|$)/)
+const lheading = edit(/^(?!bull |blockCode|fences|blockquote|heading|html)((?:.|\n(?!\s*?\n|bull |blockCode|fences|blockquote|heading|html))+?)\n {0,3}(=+|-+) *(?:\n+|$)/)
.replace(/bull/g, bullet) // lists can interrupt
+ .replace(/blockCode/g, / {4}/) // indented code blocks can interrupt
+ .replace(/fences/g, / {0,3}(?:`{3,}|~{3,})/) // fenced code blocks can interrupt
+ .replace(/blockquote/g, / {0,3}>/) // blockquote can interrupt
+ .replace(/heading/g, / {0,3}#{1,6}/) // ATX heading can interrupt
+ .replace(/html/g, / {0,3}<[^\n>]+>\n/) // block html can interrupt
.getRegex();
const _paragraph = /^([^\n]+(?:\n(?!hr|heading|lheading|blockquote|fences|list|html|table| +\n)[^\n]+)*)/;
const blockText = /^[^\n]+/;
diff --git a/test/specs/new/setext_no_blankline.html b/test/specs/new/setext_no_blankline.html
new file mode 100644
index 0000000000..88657aa7ad
--- /dev/null
+++ b/test/specs/new/setext_no_blankline.html
@@ -0,0 +1,12 @@
+indented code block
+
+=
+fenced code block
+=
+
+blockquote
+
+heading
+=
+
+=
diff --git a/test/specs/new/setext_no_blankline.md b/test/specs/new/setext_no_blankline.md
new file mode 100644
index 0000000000..f98ebd63a1
--- /dev/null
+++ b/test/specs/new/setext_no_blankline.md
@@ -0,0 +1,16 @@
+ indented code block
+=
+
+fenced code block
+```
+=
+```
+
+> blockquote
+=
+
+### heading
+=
+
+
+=