diff --git a/package.json b/package.json
index 1aafd442..a619a740 100644
--- a/package.json
+++ b/package.json
@@ -4,8 +4,8 @@
   "description": "",
   "main": "index.js",
   "scripts": {
-    "postinstall": "xattr -w com.apple.fileprovider.ignore#P 1 node_modules 2>/dev/null || true && node scripts/patch-lightningcss.mjs && node scripts/patch-endpoint-media-scope.mjs && node scripts/patch-endpoint-media-sharp-runtime.mjs && node scripts/patch-frontend-sharp-runtime.mjs && node scripts/patch-endpoint-files-upload-route.mjs && node scripts/patch-endpoint-files-upload-locales.mjs && node scripts/patch-endpoint-activitypub-locales.mjs && node scripts/patch-endpoint-homepage-locales.mjs && node scripts/patch-endpoint-homepage-identity-defaults.mjs && node scripts/patch-federation-unlisted-guards.mjs && node scripts/patch-endpoint-micropub-where-note-visibility.mjs && node scripts/patch-endpoint-posts-ai-fields.mjs && node scripts/patch-endpoint-posts-ai-cleanup.mjs && node scripts/patch-endpoint-podroll-opml-upload.mjs && node scripts/patch-preset-eleventy-ai-frontmatter.mjs && node scripts/patch-micropub-ai-block-resync.mjs && node scripts/patch-frontend-serviceworker-file.mjs && node scripts/patch-endpoint-comments-locales.mjs && node scripts/patch-conversations-collection-guards.mjs && node scripts/patch-indiekit-routes-rate-limits.mjs && node scripts/patch-indiekit-error-production-stack.mjs && node scripts/patch-indieauth-devmode-guard.mjs && node scripts/patch-listening-endpoint-runtime-guards.mjs && node scripts/patch-endpoint-github-changelog-categories.mjs && node scripts/patch-microsub-reader-ap-dispatch.mjs && node scripts/patch-endpoint-blogroll-feeds-alias.mjs && node scripts/patch-endpoint-posts-uid-lookup.mjs && node scripts/patch-endpoint-posts-prefill-url.mjs && node scripts/patch-microsub-feed-discovery.mjs && node scripts/patch-conversations-bluesky-self-filter.mjs && node scripts/patch-conversations-bluesky-cursor-fix.mjs && node scripts/patch-inbox-ignore-view-activity.mjs && node scripts/patch-inbox-skip-view-activity-parse.mjs && node scripts/patch-webmention-sender-content-scope.mjs && node scripts/patch-endpoint-micropub-source-filter.mjs && node scripts/patch-endpoint-posts-search-tags.mjs",
-    "serve": "export NODE_ENV=${NODE_ENV:-production} INDIEKIT_DEBUG=${INDIEKIT_DEBUG:-0} && node scripts/preflight-production-security.mjs && node scripts/preflight-mongo-connection.mjs && node scripts/preflight-activitypub-rsa-key.mjs && node scripts/preflight-activitypub-profile-urls.mjs && node scripts/patch-lightningcss.mjs && node scripts/patch-endpoint-media-scope.mjs && node scripts/patch-endpoint-media-sharp-runtime.mjs && node scripts/patch-frontend-sharp-runtime.mjs && node scripts/patch-endpoint-files-upload-route.mjs && node scripts/patch-endpoint-files-upload-locales.mjs && node scripts/patch-endpoint-activitypub-locales.mjs && node scripts/patch-endpoint-homepage-locales.mjs && node scripts/patch-endpoint-homepage-identity-defaults.mjs && node scripts/patch-federation-unlisted-guards.mjs && node scripts/patch-endpoint-micropub-where-note-visibility.mjs && node scripts/patch-endpoint-posts-ai-fields.mjs && node scripts/patch-endpoint-posts-ai-cleanup.mjs && node scripts/patch-endpoint-podroll-opml-upload.mjs && node scripts/patch-preset-eleventy-ai-frontmatter.mjs && node scripts/patch-micropub-ai-block-resync.mjs && node scripts/patch-frontend-serviceworker-file.mjs && node scripts/patch-endpoint-comments-locales.mjs && node scripts/patch-conversations-collection-guards.mjs && node scripts/patch-indiekit-routes-rate-limits.mjs && node scripts/patch-indiekit-error-production-stack.mjs && node scripts/patch-indieauth-devmode-guard.mjs && node scripts/patch-listening-endpoint-runtime-guards.mjs && node scripts/patch-endpoint-github-changelog-categories.mjs && node scripts/patch-microsub-reader-ap-dispatch.mjs && node scripts/patch-endpoint-blogroll-feeds-alias.mjs && node scripts/patch-endpoint-posts-uid-lookup.mjs && node scripts/patch-endpoint-posts-prefill-url.mjs && node scripts/patch-microsub-feed-discovery.mjs && node scripts/patch-conversations-bluesky-self-filter.mjs && node scripts/patch-conversations-bluesky-cursor-fix.mjs && node scripts/patch-webmention-sender-content-scope.mjs && node scripts/patch-endpoint-micropub-source-filter.mjs && node scripts/patch-endpoint-posts-search-tags.mjs && node node_modules/@indiekit/indiekit/bin/cli.js serve --config indiekit.config.mjs",
+    "postinstall": "xattr -w com.apple.fileprovider.ignore#P 1 node_modules 2>/dev/null || true && node scripts/patch-lightningcss.mjs && node scripts/patch-endpoint-media-scope.mjs && node scripts/patch-endpoint-media-sharp-runtime.mjs && node scripts/patch-frontend-sharp-runtime.mjs && node scripts/patch-endpoint-files-upload-route.mjs && node scripts/patch-endpoint-files-upload-locales.mjs && node scripts/patch-endpoint-activitypub-locales.mjs && node scripts/patch-endpoint-homepage-locales.mjs && node scripts/patch-endpoint-homepage-identity-defaults.mjs && node scripts/patch-federation-unlisted-guards.mjs && node scripts/patch-endpoint-micropub-where-note-visibility.mjs && node scripts/patch-endpoint-posts-ai-fields.mjs && node scripts/patch-endpoint-posts-ai-cleanup.mjs && node scripts/patch-endpoint-podroll-opml-upload.mjs && node scripts/patch-preset-eleventy-ai-frontmatter.mjs && node scripts/patch-micropub-ai-block-resync.mjs && node scripts/patch-frontend-serviceworker-file.mjs && node scripts/patch-endpoint-comments-locales.mjs && node scripts/patch-conversations-collection-guards.mjs && node scripts/patch-indiekit-routes-rate-limits.mjs && node scripts/patch-indiekit-error-production-stack.mjs && node scripts/patch-indieauth-devmode-guard.mjs && node scripts/patch-listening-endpoint-runtime-guards.mjs && node scripts/patch-endpoint-github-changelog-categories.mjs && node scripts/patch-microsub-reader-ap-dispatch.mjs && node scripts/patch-endpoint-blogroll-feeds-alias.mjs && node scripts/patch-endpoint-posts-uid-lookup.mjs && node scripts/patch-endpoint-posts-prefill-url.mjs && node scripts/patch-microsub-feed-discovery.mjs && node scripts/patch-conversations-bluesky-self-filter.mjs && node scripts/patch-conversations-bluesky-cursor-fix.mjs && node scripts/patch-inbox-ignore-view-activity.mjs && node scripts/patch-inbox-skip-view-activity-parse.mjs && node scripts/patch-webmention-sender-content-scope.mjs && node scripts/patch-endpoint-micropub-source-filter.mjs && node scripts/patch-endpoint-posts-search-tags.mjs && node scripts/patch-syndicate-force-checked-default.mjs",
+    "serve": "export NODE_ENV=${NODE_ENV:-production} INDIEKIT_DEBUG=${INDIEKIT_DEBUG:-0} && node scripts/preflight-production-security.mjs && node scripts/preflight-mongo-connection.mjs && node scripts/preflight-activitypub-rsa-key.mjs && node scripts/preflight-activitypub-profile-urls.mjs && node scripts/patch-lightningcss.mjs && node scripts/patch-endpoint-media-scope.mjs && node scripts/patch-endpoint-media-sharp-runtime.mjs && node scripts/patch-frontend-sharp-runtime.mjs && node scripts/patch-endpoint-files-upload-route.mjs && node scripts/patch-endpoint-files-upload-locales.mjs && node scripts/patch-endpoint-activitypub-locales.mjs && node scripts/patch-endpoint-homepage-locales.mjs && node scripts/patch-endpoint-homepage-identity-defaults.mjs && node scripts/patch-federation-unlisted-guards.mjs && node scripts/patch-endpoint-micropub-where-note-visibility.mjs && node scripts/patch-endpoint-posts-ai-fields.mjs && node scripts/patch-endpoint-posts-ai-cleanup.mjs && node scripts/patch-endpoint-podroll-opml-upload.mjs && node scripts/patch-preset-eleventy-ai-frontmatter.mjs && node scripts/patch-micropub-ai-block-resync.mjs && node scripts/patch-frontend-serviceworker-file.mjs && node scripts/patch-endpoint-comments-locales.mjs && node scripts/patch-conversations-collection-guards.mjs && node scripts/patch-indiekit-routes-rate-limits.mjs && node scripts/patch-indiekit-error-production-stack.mjs && node scripts/patch-indieauth-devmode-guard.mjs && node scripts/patch-listening-endpoint-runtime-guards.mjs && node scripts/patch-endpoint-github-changelog-categories.mjs && node scripts/patch-microsub-reader-ap-dispatch.mjs && node scripts/patch-endpoint-blogroll-feeds-alias.mjs && node scripts/patch-endpoint-posts-uid-lookup.mjs && node scripts/patch-endpoint-posts-prefill-url.mjs && node scripts/patch-microsub-feed-discovery.mjs && node scripts/patch-conversations-bluesky-self-filter.mjs && node scripts/patch-conversations-bluesky-cursor-fix.mjs && node scripts/patch-webmention-sender-content-scope.mjs && node scripts/patch-endpoint-micropub-source-filter.mjs && node scripts/patch-endpoint-posts-search-tags.mjs && node scripts/patch-syndicate-force-checked-default.mjs && node node_modules/@indiekit/indiekit/bin/cli.js serve --config indiekit.config.mjs",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "keywords": [],
diff --git a/scripts/patch-syndicate-force-checked-default.mjs b/scripts/patch-syndicate-force-checked-default.mjs
new file mode 100644
index 00000000..0b68829b
--- /dev/null
+++ b/scripts/patch-syndicate-force-checked-default.mjs
@@ -0,0 +1,78 @@
+/**
+ * Patch: when the backend "Syndicate" button is pressed for a post that has
+ * no `mp-syndicate-to` and no existing syndication URLs, fall back to targets
+ * that have `checked: true` in their options (e.g. ActivityPub) instead of
+ * doing nothing.
+ *
+ * Without this patch, force-syndicating a post that was published without
+ * any syndication targets pre-selected would silently no-op.
+ */
+import { access, readFile, writeFile } from "node:fs/promises";
+
+const candidates = [
+  "node_modules/@indiekit/endpoint-syndicate/lib/utils.js",
+  "node_modules/@rmdes/indiekit-endpoint-syndicate/lib/utils.js",
+  "node_modules/@indiekit/indiekit/node_modules/@indiekit/endpoint-syndicate/lib/utils.js",
+  "node_modules/@indiekit/indiekit/node_modules/@rmdes/indiekit-endpoint-syndicate/lib/utils.js",
+];
+
+const marker = "// syndicate-force-checked-default patch";
+
+const oldSnippet = `    }
+    // If no existing syndication URLs, don't default to all — leave empty
+  }`;
+
+const newSnippet = `    } else {
+      // syndicate-force-checked-default patch
+      syndicateTo = syndicationTargets
+        .filter((t) => t?.options?.checked)
+        .map((t) => t.info.uid);
+    }
+  }`;
+
+async function exists(filePath) {
+  try {
+    await access(filePath);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+let checked = 0;
+let patched = 0;
+
+for (const filePath of candidates) {
+  if (!(await exists(filePath))) {
+    continue;
+  }
+
+  checked += 1;
+
+  const source = await readFile(filePath, "utf8");
+
+  if (source.includes(marker)) {
+    continue;
+  }
+
+  if (!source.includes(oldSnippet)) {
+    console.warn(
+      `[postinstall] Skipping syndicate-force-checked-default patch for ${filePath}: upstream format changed`,
+    );
+    continue;
+  }
+
+  const updated = source.replace(oldSnippet, newSnippet);
+  await writeFile(filePath, updated, "utf8");
+  patched += 1;
+}
+
+if (checked === 0) {
+  console.log("[postinstall] No endpoint-syndicate utils files found");
+} else if (patched === 0) {
+  console.log("[postinstall] syndicate-force-checked-default patch already applied");
+} else {
+  console.log(
+    `[postinstall] Patched syndicate-force-checked-default in ${patched} file(s)`,
+  );
+}