diff --git a/tests/fix-2138-ship-note-lost-on-merge.test.cjs b/tests/fix-2138-ship-note-lost-on-merge.test.cjs
new file mode 100644
index 000000000..c6e75a264
--- /dev/null
+++ b/tests/fix-2138-ship-note-lost-on-merge.test.cjs
@@ -0,0 +1,63 @@
+'use strict';
+
+/**
+ * #2138 — track_shipping ship-note must be pushed onto the PR branch.
+ *
+ * ship.md's track_shipping step committed the STATE ship-note (Phase N shipped —
+ * PR #N) AFTER create_pr and never pushed it. The commit stayed local-only, so
+ * when the GitHub PR merged (especially fast/auto-merge) the ship-note was not in
+ * the source branch and never reached the default branch — STATE's ship-status
+ * was silently lost.
+ *
+ * The fix pushes the ship-note commit onto the PR branch with a `[ci skip]`
+ * trailer (honored by GitHub) so it lands on merge without triggering a redundant
+ * pipeline. This test is a source-text regression guard: ship.md IS the product
+ * the runtime loads, so asserting its track_shipping step pushes (with [ci skip])
+ * guards the deployed contract.
+ */
+
+const { describe, test } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+
+const SHIP_MD = path.join(__dirname, '..', 'gsd-core', 'workflows', 'ship.md');
+
+function extractStep(name) {
+  const content = fs.readFileSync(SHIP_MD, 'utf8');
+  const open = `<step name="${name}">`;
+  const start = content.indexOf(open);
+  assert.notEqual(start, -1, `ship.md must contain a ${name} step`);
+  const end = content.indexOf('</step>', start);
+  assert.notEqual(end, -1, `${name} step must close`);
+  return content.slice(start, end);
+}
+
+describe('#2138 ship.md track_shipping pushes the ship-note onto the PR branch', () => {
+  const step = extractStep('track_shipping');
+
+  test('track_shipping pushes the committed ship-note (not local-only)', () => {
+    // The bug was that the ship-note commit was never pushed. The fix adds a
+    // `git push origin ${CURRENT_BRANCH}` inside track_shipping.
+    assert.ok(
+      /git push origin \$\{CURRENT_BRANCH\}/.test(step),
+      'track_shipping must push the ship-note commit onto the PR branch so it survives merge (#2138)',
+    );
+  });
+
+  test('the ship-note commit carries a [ci skip] trailer to avoid a redundant pipeline', () => {
+    // GitHub honors `[ci skip]` / `[skip ci]`; the trailer suppresses the second
+    // pipeline the post-create_pr push would otherwise trigger.
+    assert.ok(
+      /\[ci skip\]|\[skip ci\]/.test(step),
+      'track_shipping ship-note commit must include a [ci skip] trailer',
+    );
+  });
+
+  test('the ship-note commit still records the phase + PR number in STATE', () => {
+    assert.ok(
+      /ship phase \$\{PHASE_NUMBER\}.*PR #\$\{PR_NUMBER\}/.test(step),
+      'track_shipping must still commit the phase + PR-number ship-note into STATE',
+    );
+  });
+});