diff --git a/scripts/patch-ap-followers-count-estimate.mjs b/scripts/patch-ap-followers-count-estimate.mjs
new file mode 100644
index 00000000..3cd1d095
--- /dev/null
+++ b/scripts/patch-ap-followers-count-estimate.mjs
@@ -0,0 +1,52 @@
+/**
+ * Patch: replace ap_followers.countDocuments() with estimatedDocumentCount()
+ * in syndicator.js log statement.
+ *
+ * countDocuments() runs an aggregate({$match:{}, $group:{n:$sum:1}}) scan.
+ * For a logging call this is unnecessary — estimatedDocumentCount() reads
+ * collection metadata (O(1), no lock contention).
+ */
+
+import { access, readFile, writeFile } from "node:fs/promises";
+
+const candidates = [
+  "node_modules/@rmdes/indiekit-endpoint-activitypub/lib/syndicator.js",
+  "node_modules/@indiekit/indiekit/node_modules/@rmdes/indiekit-endpoint-activitypub/lib/syndicator.js",
+];
+
+const MARKER = "// [patch] followers-count-estimate";
+
+const OLD = `        // Count followers for logging
+        const followerCount =
+          await plugin._collections.ap_followers.countDocuments();`;
+
+const NEW = `        // Count followers for logging
+        const followerCount =
+          await plugin._collections.ap_followers.estimatedDocumentCount(); ${MARKER}`;
+
+async function exists(p) {
+  try { await access(p); return true; } catch { return false; }
+}
+
+let patched = false;
+for (const filePath of candidates) {
+  if (!(await exists(filePath))) continue;
+  const src = await readFile(filePath, "utf8");
+  if (src.includes(MARKER)) {
+    console.log(`[postinstall] patch-ap-followers-count-estimate: already applied in ${filePath}`);
+    patched = true;
+    break;
+  }
+  if (!src.includes(OLD)) {
+    console.log(`[postinstall] patch-ap-followers-count-estimate: target snippet not found in ${filePath}`);
+    continue;
+  }
+  await writeFile(filePath, src.replace(OLD, NEW), "utf8");
+  console.log(`[postinstall] patch-ap-followers-count-estimate: applied to ${filePath}`);
+  patched = true;
+  break;
+}
+
+if (!patched) {
+  console.log("[postinstall] patch-ap-followers-count-estimate: no target file found");
+}