diff --git a/src/lib/addBlankLines.spec.ts b/src/lib/addBlankLines.spec.ts
index e4e837d..19bc6cb 100644
--- a/src/lib/addBlankLines.spec.ts
+++ b/src/lib/addBlankLines.spec.ts
@@ -33,4 +33,12 @@ describe("addBlankLines", () => {
 
     expect(result).toEqual('<a href="#">hello</a>\nparagraph');
   });
+
+  it("adds blank lines after html with a space at end", () => {
+    const markdown = "<h4>title</h4> \nparagraph";
+
+    const result = addBlankLines(markdown);
+
+    expect(result).toEqual("<h4>title</h4>\n\nparagraph");
+  });
 });
diff --git a/src/lib/addBlankLines.ts b/src/lib/addBlankLines.ts
index 6e83f71..376e018 100644
--- a/src/lib/addBlankLines.ts
+++ b/src/lib/addBlankLines.ts
@@ -1,7 +1,7 @@
 // TODO: https://github.com/beeminder/blog/issues/354
 const blockElements =
   "address|article|aside|blockquote|canvas|dd|div|dl|dt|fieldset|figcaption|figure|footer|form|h\\d|header|hr|li|main|nav|noscript|ol|p|pre|section|table|tfoot|ul|video";
-const regex = new RegExp(`(</?(${blockElements})[^>]*>)\n+`, "g");
+const regex = new RegExp(`(</?(${blockElements})[^>]*>) *\n+`, "g");
 
 export default function addBlankLines(markdown: string): string {
   return markdown.replace(regex, "$1\n\n");