diff --git a/scripts/fetch-github-projects.mjs b/scripts/fetch-github-projects.mjs
index fb0281b..9022eb7 100644
--- a/scripts/fetch-github-projects.mjs
+++ b/scripts/fetch-github-projects.mjs
@@ -53,6 +53,12 @@ export function truncate(text, max) {
   return t.length <= max ? t : t.slice(0, max - 1).trimEnd() + '…';
 }
 
+// An image or link with an inline `(url)` or a reference `[label]` target, optionally wrapped in a link.
+// Alt text, labels and URLs exclude brackets, and URLs allow only one level of parentheses,
+// so every match attempt stops at the next bracket and matching stays linear.
+const TARGET = String.raw`(?:\((?:[^()[\]\s]|\([^()[\]\s]*\))*\)|\[[^[\]]*\])`;
+const BADGE = new RegExp(String.raw`\[?!?\[[^[\]]*\]${TARGET}(?:\]${TARGET})?`, 'g');
+
 /** Pull the first real paragraph out of a README, skipping title/badges/code. */
 export function readmeExcerpt(md) {
   const lines = String(md).split('\n');
@@ -69,8 +75,8 @@ export function readmeExcerpt(md) {
     if (fence) continue;
     if (!line) { if (para.length) break; else continue; }
     if (line.startsWith('#')) continue; // heading
-    // line of images or linked badges; alt and URL exclude brackets so matching stays linear
-    if (!line.replace(/\[?!?\[[^[\]]*\]\([^()\s]*\)(?:\]\([^()\s]*\))?/g, '').trim()) continue;
+    if (!line.replace(BADGE, '').trim()) continue; // line of images or (linked) badges
+    if (/^\[[^[\]]+\]:\s/.test(line)) continue; // link reference definition
     if (/^[-=]{3,}$/.test(line)) continue; // setext underline / hr
     para.push(line);
   }
diff --git a/scripts/fetch-github-projects.test.mjs b/scripts/fetch-github-projects.test.mjs
index 2b84a8d..322dcbb 100644
--- a/scripts/fetch-github-projects.test.mjs
+++ b/scripts/fetch-github-projects.test.mjs
@@ -53,10 +53,22 @@ test('the excerpt skips linked badges, tilde fences and plain link lines', () =>
   assert.equal(readmeExcerpt(`# T\n\n${badges}\n\n~~~\ncode\n~~~\n\n[Docs](https://x/docs)\n\nReal text.`), 'Real text.');
   assert.equal(readmeExcerpt('See [the docs](https://x/docs) for more.'), 'See [the docs](https://x/docs) for more.');
   assert.equal(readmeExcerpt('~~~md\n```js\nx\n~~~\n\nReal text.'), 'Real text.');
-  // CodeQL's backtracking input: took seconds with the old badge pattern
-  const start = performance.now();
-  readmeExcerpt(`[]()${'[[]()'.repeat(28)}x`);
-  assert.ok(performance.now() - start < 100);
+});
+
+test('the excerpt skips reference-style badges and URLs with parentheses', () => {
+  const refs = '[![CI][ci-badge]][ci] ![Cov][cov]\n\n[ci-badge]: https://x/ci.svg';
+  assert.equal(readmeExcerpt(`${refs}\n\nReal text.`), 'Real text.');
+  assert.equal(readmeExcerpt('[![W](https://x/w_(a).svg)](https://x/w_(a))\n\nReal text.'), 'Real text.');
+  assert.equal(readmeExcerpt('See [a][b] for more.'), 'See [a][b] for more.');
+});
+
+test('badge matching stays fast on crafted lines', () => {
+  // the first is CodeQL's backtracking input, which took seconds with an earlier pattern
+  for (const line of [`[]()${'[[]()'.repeat(28)}x`, '[a]('.repeat(5000), '[a]['.repeat(5000), `[a](${'(b'.repeat(5000)}`]) {
+    const start = performance.now();
+    readmeExcerpt(line);
+    assert.ok(performance.now() - start < 100, line.slice(0, 8));
+  }
 });
 
 test('a repo link is found in a file with Windows line endings', () => {