diff --git a/packages/api/test/unit/beacon/genericServerTest/config.test.ts b/packages/api/test/unit/beacon/genericServerTest/config.test.ts
index e11e4cbff6cb..3e9c001bffbf 100644
--- a/packages/api/test/unit/beacon/genericServerTest/config.test.ts
+++ b/packages/api/test/unit/beacon/genericServerTest/config.test.ts
@@ -9,9 +9,7 @@ import {testData} from "../testData/config.js";
 /* eslint-disable @typescript-eslint/naming-convention */
 
 describe("beacon / config", () => {
-  describe("Run generic server test", () => {
-    runGenericServerTest<Api, ReqTypes>(config, getClient, getRoutes, testData);
-  });
+  runGenericServerTest<Api, ReqTypes>(config, getClient, getRoutes, testData);
 
   it("Serialize Partial Spec object", () => {
     const returnTypes = getReturnTypes();
diff --git a/packages/api/test/unit/beacon/genericServerTest/debug.test.ts b/packages/api/test/unit/beacon/genericServerTest/debug.test.ts
index 6f7889677ec6..9a4c4bd71ef1 100644
--- a/packages/api/test/unit/beacon/genericServerTest/debug.test.ts
+++ b/packages/api/test/unit/beacon/genericServerTest/debug.test.ts
@@ -1,5 +1,6 @@
-import {describe, it, expect, MockInstance} from "vitest";
+import {describe, it, expect, MockInstance, beforeAll, afterAll} from "vitest";
 import {toHexString} from "@chainsafe/ssz";
+import {FastifyInstance} from "fastify";
 import {ssz} from "@lodestar/types";
 import {config} from "@lodestar/config/default";
 import {Api, ReqTypes, routesData} from "../../../../src/beacon/routes/debug.js";
@@ -13,19 +14,28 @@ import {testData} from "../testData/debug.js";
 
 describe(
   "beacon / debug",
-  function () {
-    describe("Run generic server test", () => {
-      runGenericServerTest<Api, ReqTypes>(config, getClient, getRoutes, testData);
-    });
+  () => {
+    runGenericServerTest<Api, ReqTypes>(config, getClient, getRoutes, testData);
 
     // Get state by SSZ
 
     describe("getState() in SSZ format", () => {
-      const {baseUrl, server} = getTestServer();
       const mockApi = getMockApi<Api>(routesData);
-      for (const route of Object.values(getRoutes(config, mockApi))) {
-        registerRoute(server, route);
-      }
+      let baseUrl: string;
+      let server: FastifyInstance;
+
+      beforeAll(async () => {
+        const res = getTestServer();
+        server = res.server;
+        for (const route of Object.values(getRoutes(config, mockApi))) {
+          registerRoute(server, route);
+        }
+        baseUrl = await res.start();
+      });
+
+      afterAll(async () => {
+        if (server !== undefined) await server.close();
+      });
 
       for (const method of ["getState" as const, "getStateV2" as const]) {
         it(method, async () => {
diff --git a/packages/api/test/unit/beacon/genericServerTest/events.test.ts b/packages/api/test/unit/beacon/genericServerTest/events.test.ts
index 3e1c02396710..2d6c9462c1fd 100644
--- a/packages/api/test/unit/beacon/genericServerTest/events.test.ts
+++ b/packages/api/test/unit/beacon/genericServerTest/events.test.ts
@@ -1,4 +1,5 @@
-import {describe, it, expect, beforeEach, afterEach} from "vitest";
+import {describe, it, expect, beforeEach, afterEach, beforeAll, afterAll} from "vitest";
+import {FastifyInstance} from "fastify";
 import {sleep} from "@lodestar/utils";
 import {Api, routesData, EventType, BeaconEvent} from "../../../../src/beacon/routes/events.js";
 import {getClient} from "../../../../src/beacon/client/events.js";
@@ -8,11 +9,23 @@ import {getMockApi, getTestServer} from "../../../utils/utils.js";
 import {eventTestData} from "../testData/events.js";
 
 describe("beacon / events", () => {
-  const {baseUrl, server} = getTestServer();
   const mockApi = getMockApi<Api>(routesData);
-  for (const route of Object.values(getRoutes(mockApi))) {
-    registerRoute(server, route);
-  }
+  let server: FastifyInstance;
+  let baseUrl: string;
+
+  beforeAll(async () => {
+    const res = getTestServer();
+    server = res.server;
+    for (const route of Object.values(getRoutes(mockApi))) {
+      registerRoute(server, route);
+    }
+
+    baseUrl = await res.start();
+  });
+
+  afterAll(async () => {
+    if (server !== undefined) await server.close();
+  });
 
   let controller: AbortController;
   beforeEach(() => {
diff --git a/packages/api/test/utils/genericServerTest.ts b/packages/api/test/utils/genericServerTest.ts
index f0f805b7469a..4cd0263aaea8 100644
--- a/packages/api/test/utils/genericServerTest.ts
+++ b/packages/api/test/utils/genericServerTest.ts
@@ -1,4 +1,5 @@
-import {it, expect, MockInstance} from "vitest";
+import {it, expect, MockInstance, describe, beforeAll, afterAll} from "vitest";
+import {FastifyInstance} from "fastify";
 import {ChainForkConfig} from "@lodestar/config";
 import {ReqGeneric, Resolves} from "../../src/utils/index.js";
 import {FetchOpts, HttpClient, IHttpClient} from "../../src/utils/client/index.js";
@@ -28,26 +29,39 @@ export function runGenericServerTest<
   testCases: GenericServerTestCases<Api>
 ): void {
   const mockApi = getMockApi<Api>(testCases);
-  const {baseUrl, server} = getTestServer();
+  let server: FastifyInstance;
 
-  const httpClient = new HttpClientSpy({baseUrl});
-  const client = getClient(config, httpClient);
+  let client: Api;
+  let httpClient: HttpClientSpy;
 
-  for (const route of Object.values(getRoutes(config, mockApi))) {
-    registerRoute(server, route);
-  }
+  beforeAll(async () => {
+    const res = getTestServer();
+    server = res.server;
+
+    for (const route of Object.values(getRoutes(config, mockApi))) {
+      registerRoute(server, route);
+    }
+
+    const baseUrl = await res.start();
+    httpClient = new HttpClientSpy({baseUrl});
+    client = getClient(config, httpClient);
+  });
 
-  for (const key of Object.keys(testCases)) {
-    const routeId = key as keyof Api;
-    const testCase = testCases[routeId];
+  afterAll(async () => {
+    if (server !== undefined) await server.close();
+  });
+
+  describe("run generic server tests", () => {
+    it.each(Object.keys(testCases))("%s", async (key) => {
+      const routeId = key as keyof Api;
+      const testCase = testCases[routeId];
 
-    it(routeId as string, async () => {
       // Register mock data for this route
       // TODO: Look for the type error
       (mockApi[routeId] as MockInstance).mockResolvedValue(testCases[routeId].res);
 
       // Do the call
-      const res = await (client[routeId] as APIClientHandler)(...(testCase.args as any[]));
+      const res = await client[routeId](...(testCase.args as any[]));
 
       // Use spy to assert argument serialization
       if (testCase.query) {
@@ -64,7 +78,7 @@ export function runGenericServerTest<
       // Assert returned value is correct
       expect(res.response).toEqual(testCase.res);
     });
-  }
+  });
 }
 
 class HttpClientSpy extends HttpClient {
diff --git a/packages/api/test/utils/utils.ts b/packages/api/test/utils/utils.ts
index cca89c8e4fd5..b19899016117 100644
--- a/packages/api/test/utils/utils.ts
+++ b/packages/api/test/utils/utils.ts
@@ -1,13 +1,10 @@
-import {beforeAll, afterAll, MockedObject, vi} from "vitest";
+import {MockedObject, vi} from "vitest";
 import qs from "qs";
 import fastify, {FastifyInstance} from "fastify";
 import {mapValues} from "@lodestar/utils";
 import {ServerApi} from "../../src/interfaces.js";
 
-export function getTestServer(): {baseUrl: string; server: FastifyInstance} {
-  const port = Math.floor(Math.random() * (65535 - 49152)) + 49152;
-  const baseUrl = `http://localhost:${port}`;
-
+export function getTestServer(): {server: FastifyInstance; start: () => Promise<string>} {
   const server = fastify({
     ajv: {customOptions: {coerceTypes: "array"}},
     querystringParser: (str) => qs.parse(str, {comma: true, parseArrays: false}),
@@ -19,9 +16,9 @@ export function getTestServer(): {baseUrl: string; server: FastifyInstance} {
     done();
   });
 
-  beforeAll(async () => {
-    await new Promise((resolve, reject) => {
-      server.listen({port}, function (err, address) {
+  const start = (): Promise<string> =>
+    new Promise<string>((resolve, reject) => {
+      server.listen({port: 0}, function (err, address) {
         if (err !== null && err != undefined) {
           reject(err);
         } else {
@@ -29,13 +26,8 @@ export function getTestServer(): {baseUrl: string; server: FastifyInstance} {
         }
       });
     });
-  });
-
-  afterAll(async () => {
-    await server.close();
-  });
 
-  return {baseUrl, server};
+  return {start, server};
 }
 
 export function getMockApi<Api extends Record<string, any>>(
diff --git a/packages/validator/src/util/clock.ts b/packages/validator/src/util/clock.ts
index ca29eacd41c2..837fb82809bd 100644
--- a/packages/validator/src/util/clock.ts
+++ b/packages/validator/src/util/clock.ts
@@ -138,7 +138,7 @@ export class Clock implements IClock {
  */
 export function getCurrentSlotAround(config: ChainForkConfig, genesisTime: TimeSeconds): Slot {
   const diffInSeconds = Date.now() / 1000 - genesisTime;
-  const slotsSinceGenesis = Math.round(diffInSeconds / config.SECONDS_PER_SLOT);
+  const slotsSinceGenesis = Math.floor(diffInSeconds / config.SECONDS_PER_SLOT);
   return GENESIS_SLOT + slotsSinceGenesis;
 }
 
diff --git a/packages/validator/test/unit/utils/clock.test.ts b/packages/validator/test/unit/utils/clock.test.ts
index 15f95ddbe2ee..dfa9d386e663 100644
--- a/packages/validator/test/unit/utils/clock.test.ts
+++ b/packages/validator/test/unit/utils/clock.test.ts
@@ -11,7 +11,7 @@ describe("util / Clock", function () {
 
   beforeEach(() => {
     controller = new AbortController();
-    vi.useFakeTimers();
+    vi.useFakeTimers({now: Date.now()});
   });
 
   afterEach(() => {