diff --git a/.changeset/calm-fern-meadow.md b/.changeset/calm-fern-meadow.md
new file mode 100644
index 000000000..8ecf68612
--- /dev/null
+++ b/.changeset/calm-fern-meadow.md
@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 3369
+---
+**`gsd-tools validate health` no longer flags `.planning/WINDOWS.md` as an unrecognized file** — the broken-windows ledger that gsd-core's own `windows` command writes is now registered as a canonical `.planning/` artifact. Previously the W019 warning advised archiving or deleting a file that, with `workflow.windows_enforce` on, gates `/gsd-ship`. (#3224)
diff --git a/src/artifacts.cts b/src/artifacts.cts
index 7beea9853..2f2007b2e 100644
--- a/src/artifacts.cts
+++ b/src/artifacts.cts
@@ -24,6 +24,7 @@ export const CANONICAL_EXACT: ReadonlySet<string> = new Set([
   'config.json',
   'CLAUDE.md',
   'RETROSPECTIVE.md',
+  'WINDOWS.md', // #3224: broken-windows ledger (src/broken-windows.cts, LEDGER_FILE_NAME)
 ]);
 
 // Pattern-match canonical file names (regex tests on the basename)
diff --git a/tests/artifacts.test.cjs b/tests/artifacts.test.cjs
index 1fcae98e2..4f048e3ad 100644
--- a/tests/artifacts.test.cjs
+++ b/tests/artifacts.test.cjs
@@ -23,7 +23,7 @@ describe('CANONICAL_EXACT', () => {
     const expected = [
       'PROJECT.md', 'ROADMAP.md', 'STATE.md', 'REQUIREMENTS.md',
       'MILESTONES.md', 'BACKLOG.md', 'LEARNINGS.md', 'THREADS.md',
-      'config.json', 'CLAUDE.md', 'RETROSPECTIVE.md',
+      'config.json', 'CLAUDE.md', 'RETROSPECTIVE.md', 'WINDOWS.md',
     ];
     for (const name of expected) {
       assert.ok(CANONICAL_EXACT.has(name), `expected ${name} in CANONICAL_EXACT`);
@@ -58,6 +58,15 @@ describe('isCanonicalPlanningFile', () => {
     assert.strictEqual(isCanonicalPlanningFile('config.json'), true);
   });
 
+  test('#3224: WINDOWS.md (broken-windows ledger) is a canonical .planning/ artifact', () => {
+    // gsd-core itself writes .planning/WINDOWS.md (src/broken-windows.cts,
+    // LEDGER_FILE_NAME = 'WINDOWS.md'). Before #3224 it was absent from the
+    // registry, so validate health flagged it W019 "Unrecognized" with advice to
+    // delete a ledger that can gate /gsd-ship under workflow.windows_enforce.
+    assert.ok(CANONICAL_EXACT.has('WINDOWS.md'), 'WINDOWS.md must be in CANONICAL_EXACT');
+    assert.strictEqual(isCanonicalPlanningFile('WINDOWS.md'), true);
+  });
+
   test('returns false for unrecognized file', () => {
     assert.strictEqual(isCanonicalPlanningFile('random-file.md'), false);
   });