diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7c0383cc..e0c5e4b7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,7 +15,7 @@ jobs:
 
     services:
       redis:
-        image: redislabs/rejson:latest
+        image: redis/redis-stack-server:latest
         ports:
           - 6379:6379
         options: >-
diff --git a/package-lock.json b/package-lock.json
index aa76cd2a..d3a9d735 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12,7 +12,7 @@
 				"@koa/router": "^12.0.1",
 				"@maxmind/geoip2-node": "^4.2.0",
 				"@redocly/openapi-core": "^1.6.0",
-				"@socket.io/redis-adapter": "^8.2.1",
+				"@socket.io/redis-adapter": "github:MartinKolarik/socket.io-redis-adapter#dist",
 				"adm-zip": "^0.5.10",
 				"any-ascii": "^0.3.2",
 				"bluebird": "^3.7.2",
@@ -5322,8 +5322,8 @@
 		},
 		"node_modules/@socket.io/redis-adapter": {
 			"version": "8.2.1",
-			"resolved": "https://registry.npmjs.org/@socket.io/redis-adapter/-/redis-adapter-8.2.1.tgz",
-			"integrity": "sha512-6Dt7EZgGSBP0qvXeOKGx7NnSr2tPMbVDfDyL97zerZo+v69hMfL99skMCL3RKZlWVqLyRme2T0wcy3udHhtOsg==",
+			"resolved": "git+ssh://git@github.com/MartinKolarik/socket.io-redis-adapter.git#1f6dfc58b8e94593c6f4193b8e3702b9c733d1d0",
+			"license": "MIT",
 			"dependencies": {
 				"debug": "~4.3.1",
 				"notepack.io": "~3.0.1",
diff --git a/package.json b/package.json
index 96d24d6b..bb886220 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,7 @@
 		"@koa/router": "^12.0.1",
 		"@maxmind/geoip2-node": "^4.2.0",
 		"@redocly/openapi-core": "^1.6.0",
-		"@socket.io/redis-adapter": "^8.2.1",
+		"@socket.io/redis-adapter": "github:MartinKolarik/socket.io-redis-adapter#dist",
 		"adm-zip": "^0.5.10",
 		"any-ascii": "^0.3.2",
 		"bluebird": "^3.7.2",
diff --git a/src/lib/ws/server.ts b/src/lib/ws/server.ts
index 1dc82402..f212d0db 100644
--- a/src/lib/ws/server.ts
+++ b/src/lib/ws/server.ts
@@ -1,5 +1,5 @@
 import { type RemoteSocket, Server, Socket } from 'socket.io';
-import { createAdapter } from '@socket.io/redis-adapter';
+import { createShardedAdapter } from '@socket.io/redis-adapter';
 // eslint-disable-next-line n/no-missing-import
 import type { DefaultEventsMap } from 'socket.io/dist/typed-events.js';
 import type { Probe } from '../../probe/types.js';
@@ -32,8 +32,8 @@ export const initWsServer = async () => {
 		pingTimeout: 3000,
 	});
 
-	io.adapter(createAdapter(pubClient, subClient, {
-		publishOnSpecificResponseChannel: true,
+	io.adapter(createShardedAdapter(pubClient, subClient, {
+		subscriptionMode: 'static',
 	}));
 };
 
diff --git a/src/measurement/runner.ts b/src/measurement/runner.ts
index 4c134679..e05e44e6 100644
--- a/src/measurement/runner.ts
+++ b/src/measurement/runner.ts
@@ -1,7 +1,7 @@
 import config from 'config';
 import type { Server } from 'socket.io';
 import createHttpError from 'http-errors';
-import { getWsServer } from '../lib/ws/server.js';
+import { getWsServer, PROBES_NAMESPACE } from '../lib/ws/server.js';
 import { getProbeRouter, type ProbeRouter } from '../probe/router.js';
 import type { Probe } from '../probe/types.js';
 import { getMetricsAgent, type MetricsAgent } from '../lib/metrics.js';
@@ -61,7 +61,7 @@ export class MeasurementRunner {
 		const maxInProgressProbes = config.get<number>('measurement.maxInProgressProbes');
 		onlineProbesMap.forEach((probe, index) => {
 			const inProgressUpdates = request.inProgressUpdates && inProgressProbes++ < maxInProgressProbes;
-			this.io.of('probes').to(probe.client).emit('probe:measurement:request', {
+			this.io.of(PROBES_NAMESPACE).to(probe.client).emit('probe:measurement:request', {
 				measurementId,
 				testId: index.toString(),
 				measurement: {
diff --git a/test/tests/unit/measurement/runner.test.ts b/test/tests/unit/measurement/runner.test.ts
index 910481d8..06e73a2b 100644
--- a/test/tests/unit/measurement/runner.test.ts
+++ b/test/tests/unit/measurement/runner.test.ts
@@ -40,7 +40,7 @@ describe('MeasurementRunner', () => {
 	beforeEach(() => {
 		sinon.resetHistory();
 		to.returns({ emit });
-		io.of.returns({ to } as any);
+		io.of.withArgs('/probes').returns({ to } as any);
 		store.createMeasurement.resolves('measurementid');
 		testId = 0;
 	});