diff --git a/package-lock.json b/package-lock.json
index ad7e6ad..10a5d64 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@sqlitecloud/drivers",
-  "version": "1.0.878",
+  "version": "1.0.880",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@sqlitecloud/drivers",
-      "version": "1.0.878",
+      "version": "1.0.880",
       "license": "MIT",
       "dependencies": {
         "buffer": "^6.0.3",
diff --git a/package.json b/package.json
index abc1a2d..6f0f105 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@sqlitecloud/drivers",
-  "version": "1.0.878",
+  "version": "1.0.880",
   "description": "SQLiteCloud drivers for Typescript/Javascript in edge, web and node clients",
   "main": "./lib/index.js",
   "types": "./lib/index.d.ts",
diff --git a/src/drivers/connection-ws.ts b/src/drivers/connection-ws.ts
index c467313..917118d 100644
--- a/src/drivers/connection-ws.ts
+++ b/src/drivers/connection-ws.ts
@@ -98,14 +98,14 @@ export class SQLiteCloudWebsocketConnection extends SQLiteCloudConnection {
         // hostname (eg crvheg7dhk.g4 from crvheg7dhk.g4.sqlite.cloud) to form the gateway host
         // (→ crvheg7dhk.g4.gateway.sqlite.cloud). For local development, pass a `gatewayurl`
         // containing `localhost` — the driver routes TCP to it and injects the tenant Host header
-        // separately so the gateway still tenant-routes correctly.
+        // (with the gateway marker label) so the gateway still tenant-routes correctly.
         const authToken = this.config.apikey || this.config.token
         const ioOpts: Record<string, unknown> = { auth: { token: authToken }, parser: createSocketIOParser(websocketMaxAttachments) }
         let gatewayUrl: string
         if (this.config.gatewayurl?.includes('localhost')) {
           const raw = this.config.gatewayurl
           gatewayUrl = raw.startsWith('ws://') || raw.startsWith('wss://') ? raw : `ws://${raw}`
-          ioOpts.extraHeaders = { Host: this.config.host }
+          ioOpts.extraHeaders = { Host: buildGatewayHost(this.config.host as string) }
           ioOpts.transports = ['websocket']
         } else {
           const gatewayHost = buildGatewayHost(this.config.host as string, this.config.gatewayurl)
diff --git a/test/connection-ws-unit.test.ts b/test/connection-ws-unit.test.ts
index 968810f..ae3de89 100644
--- a/test/connection-ws-unit.test.ts
+++ b/test/connection-ws-unit.test.ts
@@ -44,6 +44,36 @@ describe('websocket transport helpers', () => {
     expect(decoder.opts?.maxAttachments).toBe(321)
   })
 
+  it('should connect to localhost gateway with the marker-augmented Host header', () => {
+    const socket = {
+      connected: false,
+      on: jest.fn(),
+      removeAllListeners: jest.fn(),
+      close: jest.fn()
+    }
+    const mockedIo = io as jest.MockedFunction<typeof io>
+    mockedIo.mockReturnValue(socket as any)
+
+    const connection = Object.create(SQLiteCloudWebsocketConnection.prototype) as any
+    connection.connectTransport(
+      {
+        connectionstring: 'sqlitecloud://host.sqlite.cloud/database?apikey=secret',
+        host: 'host.sqlite.cloud',
+        apikey: 'secret',
+        gatewayurl: 'ws://localhost:8090'
+      },
+      jest.fn()
+    )
+
+    expect(mockedIo).toHaveBeenCalledWith(
+      'ws://localhost:8090',
+      expect.objectContaining({
+        extraHeaders: { Host: 'host.gateway.sqlite.cloud' },
+        transports: ['websocket']
+      })
+    )
+  })
+
   it('should encode bigint values before sending JSON payloads', () => {
     expect(
       encodeBigIntMarkers({