diff --git a/CHANGELOG.md b/CHANGELOG.md
index e21dd13..3ecd8a7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.1.2] - 2026-09-04
+
+### Fixed
+
+- Database integration tests now serialize direct extension provisioning with
+  `createIndex`, preventing concurrent `CREATE EXTENSION` calls from racing on
+  fresh CI databases.
+
 ## [0.1.1] - 2026-09-04
 
 ### Fixed
diff --git a/bun.lock b/bun.lock
index 66f31a0..4193b12 100644
--- a/bun.lock
+++ b/bun.lock
@@ -32,7 +32,7 @@
     },
     "packages/core": {
       "name": "searchgres",
-      "version": "0.1.1",
+      "version": "0.1.2",
       "dependencies": {
         "@opentelemetry/api": "^1.9.1",
         "ai": "^7.0.79",
diff --git a/packages/core/package.json b/packages/core/package.json
index 2bc158a..8cae090 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -1,6 +1,6 @@
 {
   "name": "searchgres",
-  "version": "0.1.1",
+  "version": "0.1.2",
   "description": "Postgres-native hybrid search: semantic + BM25 retrieval with composable hierarchy, metadata, temporal, and regex filtering.",
   "license": "Apache-2.0",
   "type": "module",
diff --git a/packages/core/src/create-index.ts b/packages/core/src/create-index.ts
index d835857..907e01e 100644
--- a/packages/core/src/create-index.ts
+++ b/packages/core/src/create-index.ts
@@ -1,7 +1,7 @@
 import type postgres from "postgres";
 import { type IndexConfig, normalizeIndexConfig } from "./config.ts";
 import { ensureExtension } from "./db/extensions.ts";
-import { acquireAdvisoryLock, advisoryLockKey } from "./db/lock.ts";
+import { acquireAdvisoryLock, CREATE_INDEX_LOCK_KEY } from "./db/lock.ts";
 import { ensurePostgresVersion } from "./db/preflight.ts";
 import { createBatchUpsertRoutine } from "./db/routines/batch-upsert.ts";
 import { createRecordRoutines } from "./db/routines/records.ts";
@@ -43,7 +43,7 @@ export async function createIndex(
       ...DEFAULT_MIGRATION_TIMEOUTS,
       lockTimeout: DEFAULT_MIGRATION_LOCK_TIMEOUT,
     });
-    await acquireAdvisoryLock(tx, advisoryLockKey("searchgres:create-index"));
+    await acquireAdvisoryLock(tx, CREATE_INDEX_LOCK_KEY);
     await setLockTimeout(tx, DEFAULT_MIGRATION_TIMEOUTS.lockTimeout);
     await ensurePostgresVersion(tx);
 
diff --git a/packages/core/src/db/lock.ts b/packages/core/src/db/lock.ts
index 0db9351..f3d972e 100644
--- a/packages/core/src/db/lock.ts
+++ b/packages/core/src/db/lock.ts
@@ -10,6 +10,9 @@ export function advisoryLockKey(name: string): AdvisoryLockKey {
   return [digest.readInt32BE(0), digest.readInt32BE(4)];
 }
 
+/** Serializes index provisioning, including required extension installation. */
+export const CREATE_INDEX_LOCK_KEY = advisoryLockKey("searchgres:create-index");
+
 /** Block transaction-locally until an advisory lock is acquired or times out. */
 export async function acquireAdvisoryLock(
   sql: postgres.ISql,
diff --git a/packages/core/src/version.ts b/packages/core/src/version.ts
index cd724f4..f44ad77 100644
--- a/packages/core/src/version.ts
+++ b/packages/core/src/version.ts
@@ -10,4 +10,4 @@
  * This is package metadata only. Immutable index schemas use their own format
  * marker and never derive compatibility from the library package version.
  */
-export const LIBRARY_VERSION = "0.1.1";
+export const LIBRARY_VERSION = "0.1.2";
diff --git a/packages/core/test/db.integration.test.ts b/packages/core/test/db.integration.test.ts
index ac103c4..a6d3c59 100644
--- a/packages/core/test/db.integration.test.ts
+++ b/packages/core/test/db.integration.test.ts
@@ -5,7 +5,11 @@ import {
   type ExtensionRequirement,
   ensureExtension,
 } from "../src/db/extensions.ts";
-import { acquireAdvisoryLock, advisoryLockKey } from "../src/db/lock.ts";
+import {
+  acquireAdvisoryLock,
+  advisoryLockKey,
+  CREATE_INDEX_LOCK_KEY,
+} from "../src/db/lock.ts";
 import {
   ensurePostgresVersion,
   MINIMUM_POSTGRES_VERSION_NUM,
@@ -39,6 +43,11 @@ test("accepts PostgreSQL 18", async () => {
 
 test("ensures supplied extensions with an empty search path", async () => {
   const extensions = await sql.begin(async (tx) => {
+    // This test provisions extensions directly while other test files may call
+    // createIndex against the same fresh database. Honor ensureExtension's
+    // caller-owned locking contract so those CREATE EXTENSION statements
+    // cannot race.
+    await acquireAdvisoryLock(tx, CREATE_INDEX_LOCK_KEY);
     await tx.unsafe("set local search_path to ''");
     const results = [];
     for (const requirement of requiredExtensions) {