diff --git a/bindings/javascript/packages/browser/promise-bundle.ts b/bindings/javascript/packages/browser/promise-bundle.ts
index 8166baff1..cfff570e2 100644
--- a/bindings/javascript/packages/browser/promise-bundle.ts
+++ b/bindings/javascript/packages/browser/promise-bundle.ts
@@ -11,29 +11,29 @@ async function init(): Promise<Worker> {
 }
 
 class Database extends DatabasePromise {
-    worker: Worker | null;
+    #worker: Worker | null;
     constructor(path: string, opts: DatabaseOpts = {}) {
         super(new NativeDatabase(path, opts) as unknown as any)
     }
     override async connect() {
-        if (!this.db.memory) {
+        if (!this.memory) {
             const worker = await init();
             await Promise.all([
                 registerFileAtWorker(worker, this.name),
                 registerFileAtWorker(worker, `${this.name}-wal`)
             ]);
-            this.worker = worker;
+            this.#worker = worker;
         }
         await super.connect();
     }
     async close() {
-        if (this.name != null && this.worker != null) {
+        if (this.name != null && this.#worker != null) {
             await Promise.all([
-                unregisterFileAtWorker(this.worker, this.name),
-                unregisterFileAtWorker(this.worker, `${this.name}-wal`)
+                unregisterFileAtWorker(this.#worker, this.name),
+                unregisterFileAtWorker(this.#worker, `${this.name}-wal`)
             ]);
         }
-        this.db.close();
+        await super.close();
     }
 }
 
diff --git a/bindings/javascript/packages/browser/promise-default.ts b/bindings/javascript/packages/browser/promise-default.ts
index ddc4e3ab0..7c96e4fbf 100644
--- a/bindings/javascript/packages/browser/promise-default.ts
+++ b/bindings/javascript/packages/browser/promise-default.ts
@@ -11,29 +11,29 @@ async function init(): Promise<Worker> {
 }
 
 class Database extends DatabasePromise {
-    worker: Worker | null;
+    #worker: Worker | null;
     constructor(path: string, opts: DatabaseOpts = {}) {
         super(new NativeDatabase(path, opts) as unknown as any)
     }
     override async connect() {
-        if (!this.db.memory) {
+        if (!this.memory) {
             const worker = await init();
             await Promise.all([
                 registerFileAtWorker(worker, this.name),
                 registerFileAtWorker(worker, `${this.name}-wal`)
             ]);
-            this.worker = worker;
+            this.#worker = worker;
         }
         await super.connect();
     }
     async close() {
-        if (this.name != null && this.worker != null) {
+        if (this.name != null && this.#worker != null) {
             await Promise.all([
-                unregisterFileAtWorker(this.worker, this.name),
-                unregisterFileAtWorker(this.worker, `${this.name}-wal`)
+                unregisterFileAtWorker(this.#worker, this.name),
+                unregisterFileAtWorker(this.#worker, `${this.name}-wal`)
             ]);
         }
-        this.db.close();
+        await super.close();
     }
 }
 
diff --git a/bindings/javascript/packages/browser/promise-turbopack-hack.ts b/bindings/javascript/packages/browser/promise-turbopack-hack.ts
index 507172004..7870b74f5 100644
--- a/bindings/javascript/packages/browser/promise-turbopack-hack.ts
+++ b/bindings/javascript/packages/browser/promise-turbopack-hack.ts
@@ -11,29 +11,29 @@ async function init(): Promise<Worker> {
 }
 
 class Database extends DatabasePromise {
-    worker: Worker | null;
+    #worker: Worker | null;
     constructor(path: string, opts: DatabaseOpts = {}) {
         super(new NativeDatabase(path, opts) as unknown as any)
     }
     override async connect() {
-        if (!this.db.memory) {
+        if (!this.memory) {
             const worker = await init();
             await Promise.all([
                 registerFileAtWorker(worker, this.name),
                 registerFileAtWorker(worker, `${this.name}-wal`)
             ]);
-            this.worker = worker;
+            this.#worker = worker;
         }
         await super.connect();
     }
     async close() {
-        if (this.name != null && this.worker != null) {
+        if (this.name != null && this.#worker != null) {
             await Promise.all([
-                unregisterFileAtWorker(this.worker, this.name),
-                unregisterFileAtWorker(this.worker, `${this.name}-wal`)
+                unregisterFileAtWorker(this.#worker, this.name),
+                unregisterFileAtWorker(this.#worker, `${this.name}-wal`)
             ]);
         }
-        this.db.close();
+        await super.close();
     }
 }
 
diff --git a/bindings/javascript/packages/browser/promise-vite-dev-hack.ts b/bindings/javascript/packages/browser/promise-vite-dev-hack.ts
index 66e23716f..838e253a2 100644
--- a/bindings/javascript/packages/browser/promise-vite-dev-hack.ts
+++ b/bindings/javascript/packages/browser/promise-vite-dev-hack.ts
@@ -11,29 +11,29 @@ async function init(): Promise<Worker> {
 }
 
 class Database extends DatabasePromise {
-    worker: Worker | null;
+    #worker: Worker | null;
     constructor(path: string, opts: DatabaseOpts = {}) {
         super(new NativeDatabase(path, opts) as unknown as any)
     }
     override async connect() {
-        if (!this.db.memory) {
+        if (!this.memory) {
             const worker = await init();
             await Promise.all([
                 registerFileAtWorker(worker, this.name),
                 registerFileAtWorker(worker, `${this.name}-wal`)
             ]);
-            this.worker = worker;
+            this.#worker = worker;
         }
         await super.connect();
     }
     async close() {
-        if (this.name != null && this.worker != null) {
+        if (this.name != null && this.#worker != null) {
             await Promise.all([
-                unregisterFileAtWorker(this.worker, this.name),
-                unregisterFileAtWorker(this.worker, `${this.name}-wal`)
+                unregisterFileAtWorker(this.#worker, this.name),
+                unregisterFileAtWorker(this.#worker, `${this.name}-wal`)
             ]);
         }
-        this.db.close();
+        await super.close();
     }
 }
 
diff --git a/bindings/javascript/packages/common/compat.ts b/bindings/javascript/packages/common/compat.ts
index 819889a2a..44c99e17f 100644
--- a/bindings/javascript/packages/common/compat.ts
+++ b/bindings/javascript/packages/common/compat.ts
@@ -29,7 +29,13 @@ function createErrorByName(name, message) {
  * Database represents a connection that can prepare and execute SQL statements.
  */
 class Database {
-  db: NativeDatabase;
+  name: string;
+  readonly: boolean;
+  open: boolean;
+  memory: boolean;
+  inTransaction: boolean;
+
+  private db: NativeDatabase;
   private _inTransaction: boolean = false;
 
   /**
@@ -47,10 +53,11 @@ class Database {
     this.db.connectSync();
 
     Object.defineProperties(this, {
-      inTransaction: { get: () => this._inTransaction },
       name: { get: () => this.db.path },
       readonly: { get: () => this.db.readonly },
       open: { get: () => this.db.open },
+      memory: { get: () => this.db.memory },
+      inTransaction: { get: () => this._inTransaction },
     });
   }
 
@@ -65,7 +72,7 @@ class Database {
     }
 
     try {
-      return new Statement(this.db.prepare(sql), this);
+      return new Statement(this.db.prepare(sql), this.db);
     } catch (err) {
       throw convertError(err);
     }
@@ -202,11 +209,11 @@ class Database {
  */
 class Statement {
   stmt: NativeStatement;
-  db: Database;
+  db: NativeDatabase;
 
-  constructor(stmt: NativeStatement, database: Database) {
+  constructor(stmt: NativeStatement, db: NativeDatabase) {
     this.stmt = stmt;
-    this.db = database;
+    this.db = db;
   }
 
   /**
@@ -264,14 +271,14 @@ class Statement {
    * Executes the SQL statement and returns an info object.
    */
   run(...bindParameters) {
-    const totalChangesBefore = this.db.db.totalChanges();
+    const totalChangesBefore = this.db.totalChanges();
 
     this.stmt.reset();
     bindParams(this.stmt, bindParameters);
     for (; ;) {
       const stepResult = this.stmt.stepSync();
       if (stepResult === STEP_IO) {
-        this.db.db.ioLoopSync();
+        this.db.ioLoopSync();
         continue;
       }
       if (stepResult === STEP_DONE) {
@@ -283,8 +290,8 @@ class Statement {
       }
     }
 
-    const lastInsertRowid = this.db.db.lastInsertRowid();
-    const changes = this.db.db.totalChanges() === totalChangesBefore ? 0 : this.db.db.changes();
+    const lastInsertRowid = this.db.lastInsertRowid();
+    const changes = this.db.totalChanges() === totalChangesBefore ? 0 : this.db.changes();
 
     return { changes, lastInsertRowid };
   }
@@ -300,7 +307,7 @@ class Statement {
     for (; ;) {
       const stepResult = this.stmt.stepSync();
       if (stepResult === STEP_IO) {
-        this.db.db.ioLoopSync();
+        this.db.ioLoopSync();
         continue;
       }
       if (stepResult === STEP_DONE) {
@@ -324,7 +331,7 @@ class Statement {
     while (true) {
       const stepResult = this.stmt.stepSync();
       if (stepResult === STEP_IO) {
-        this.db.db.ioLoopSync();
+        this.db.ioLoopSync();
         continue;
       }
       if (stepResult === STEP_DONE) {
@@ -348,7 +355,7 @@ class Statement {
     for (; ;) {
       const stepResult = this.stmt.stepSync();
       if (stepResult === STEP_IO) {
-        this.db.db.ioLoopSync();
+        this.db.ioLoopSync();
         continue;
       }
       if (stepResult === STEP_DONE) {
diff --git a/bindings/javascript/packages/common/promise.ts b/bindings/javascript/packages/common/promise.ts
index 19d8e153a..bf6b1e8dd 100644
--- a/bindings/javascript/packages/common/promise.ts
+++ b/bindings/javascript/packages/common/promise.ts
@@ -30,18 +30,25 @@ function createErrorByName(name, message) {
  * Database represents a connection that can prepare and execute SQL statements.
  */
 class Database {
-  db: NativeDatabase;
-  execLock: AsyncLock;
   name: string;
+  readonly: boolean;
+  open: boolean;
+  memory: boolean;
+  inTransaction: boolean;
+
+  private db: NativeDatabase;
+  private execLock: AsyncLock;
   private _inTransaction: boolean = false;
+
   constructor(db: NativeDatabase) {
     this.db = db;
     this.execLock = new AsyncLock();
     Object.defineProperties(this, {
-      inTransaction: { get: () => this._inTransaction },
       name: { get: () => this.db.path },
       readonly: { get: () => this.db.readonly },
       open: { get: () => this.db.open },
+      memory: { get: () => this.db.memory },
+      inTransaction: { get: () => this._inTransaction },
     });
   }
 
@@ -60,7 +67,7 @@ class Database {
     }
 
     try {
-      return new Statement(this.db.prepare(sql), this);
+      return new Statement(this.db.prepare(sql), this.db, this.execLock);
     } catch (err) {
       throw convertError(err);
     }
@@ -196,11 +203,14 @@ class Database {
  * Statement represents a prepared SQL statement that can be executed.
  */
 class Statement {
-  stmt: NativeStatement;
-  db: Database;
-  constructor(stmt, database) {
+  private stmt: NativeStatement;
+  private db: NativeDatabase;
+  private execLock: AsyncLock;
+
+  constructor(stmt: NativeStatement, db: NativeDatabase, execLock: AsyncLock) {
     this.stmt = stmt;
-    this.db = database;
+    this.db = db;
+    this.execLock = execLock;
   }
 
   /**
@@ -258,17 +268,17 @@ class Statement {
    * Executes the SQL statement and returns an info object.
    */
   async run(...bindParameters) {
-    const totalChangesBefore = this.db.db.totalChanges();
+    const totalChangesBefore = this.db.totalChanges();
 
     this.stmt.reset();
     bindParams(this.stmt, bindParameters);
 
-    await this.db.execLock.acquire();
+    await this.execLock.acquire();
     try {
       while (true) {
         const stepResult = await this.stmt.stepSync();
         if (stepResult === STEP_IO) {
-          await this.db.db.ioLoopAsync();
+          await this.db.ioLoopAsync();
           continue;
         }
         if (stepResult === STEP_DONE) {
@@ -280,12 +290,12 @@ class Statement {
         }
       }
 
-      const lastInsertRowid = this.db.db.lastInsertRowid();
-      const changes = this.db.db.totalChanges() === totalChangesBefore ? 0 : this.db.db.changes();
+      const lastInsertRowid = this.db.lastInsertRowid();
+      const changes = this.db.totalChanges() === totalChangesBefore ? 0 : this.db.changes();
 
       return { changes, lastInsertRowid };
     } finally {
-      this.db.execLock.release();
+      this.execLock.release();
     }
   }
 
@@ -298,12 +308,12 @@ class Statement {
     this.stmt.reset();
     bindParams(this.stmt, bindParameters);
 
-    await this.db.execLock.acquire();
+    await this.execLock.acquire();
     try {
       while (true) {
         const stepResult = await this.stmt.stepSync();
         if (stepResult === STEP_IO) {
-          await this.db.db.ioLoopAsync();
+          await this.db.ioLoopAsync();
           continue;
         }
         if (stepResult === STEP_DONE) {
@@ -314,7 +324,7 @@ class Statement {
         }
       }
     } finally {
-      this.db.execLock.release();
+      this.execLock.release();
     }
   }
 
@@ -327,12 +337,12 @@ class Statement {
     this.stmt.reset();
     bindParams(this.stmt, bindParameters);
 
-    await this.db.execLock.acquire();
+    await this.execLock.acquire();
     try {
       while (true) {
         const stepResult = await this.stmt.stepSync();
         if (stepResult === STEP_IO) {
-          await this.db.db.ioLoopAsync();
+          await this.db.ioLoopAsync();
           continue;
         }
         if (stepResult === STEP_DONE) {
@@ -343,7 +353,7 @@ class Statement {
         }
       }
     } finally {
-      this.db.execLock.release();
+      this.execLock.release();
     }
   }
 
@@ -357,12 +367,12 @@ class Statement {
     bindParams(this.stmt, bindParameters);
     const rows: any[] = [];
 
-    await this.db.execLock.acquire();
+    await this.execLock.acquire();
     try {
       while (true) {
         const stepResult = await this.stmt.stepSync();
         if (stepResult === STEP_IO) {
-          await this.db.db.ioLoopAsync();
+          await this.db.ioLoopAsync();
           continue;
         }
         if (stepResult === STEP_DONE) {
@@ -375,7 +385,7 @@ class Statement {
       return rows;
     }
     finally {
-      this.db.execLock.release();
+      this.execLock.release();
     }
   }