diff --git a/packages/ai/CHANGELOG.md b/packages/ai/CHANGELOG.md
index 724e1cf1a..148f96f92 100644
--- a/packages/ai/CHANGELOG.md
+++ b/packages/ai/CHANGELOG.md
@@ -15,6 +15,9 @@
 ### Fixed
 
 - Fixed Google Vertex AI multi-region locations `eu` and `us` building invalid hosts (`eu-aiplatform.googleapis.com` / `us-aiplatform.googleapis.com`) that 404. Both Gemini GenerateContent and Claude/OpenAI-compat Vertex routes now resolve the REP endpoints (`aiplatform.eu.rep.googleapis.com` / `aiplatform.us.rep.googleapis.com`).
+### Fixed
+
+- Fixed `SqliteAuthCredentialStore.close()` leaking eight prepared statements (`updateIfMatches`, `updateIfMatchesWithLease`, `deleteIfMatchesWithLease`, `deleteCachePrefix`, and the four credential-refresh-lease statements), which kept the SQLite connection alive after `close()`. On Windows the auth DB and its `-wal`/`-shm` files stayed locked, so temp-dir cleanup intermittently failed with `EBUSY`; on POSIX the handle leaked silently.
 
 ## [17.1.6] - 2026-07-27
 
diff --git a/packages/ai/src/auth-storage.ts b/packages/ai/src/auth-storage.ts
index 51b9f25ac..ba7e2ffa6 100644
--- a/packages/ai/src/auth-storage.ts
+++ b/packages/ai/src/auth-storage.ts
@@ -7923,6 +7923,14 @@ export class SqliteAuthCredentialStore implements AuthCredentialStore {
 		this.#updateUsageHistoryStmt.finalize();
 		this.#insertUsageCostStmt.finalize();
 		this.#listUsageCostsStmt.finalize();
+		this.#updateIfMatchesStmt.finalize();
+		this.#updateIfMatchesWithLeaseStmt.finalize();
+		this.#deleteIfMatchesWithLeaseStmt.finalize();
+		this.#deleteCachePrefixStmt.finalize();
+		this.#acquireCredentialRefreshLeaseStmt.finalize();
+		this.#getCredentialRefreshLeaseStmt.finalize();
+		this.#renewCredentialRefreshLeaseStmt.finalize();
+		this.#releaseCredentialRefreshLeaseStmt.finalize();
 		this.#db.close();
 	}
 }