diff --git a/package.json b/package.json
index cbac5e5..147c01d 100644
--- a/package.json
+++ b/package.json
@@ -60,7 +60,7 @@
     "c8": "^11.0.0",
     "del-cli": "^7.0.0",
     "hot-hook": "^1.0.0",
-    "ioredis": "^5.11.1",
+    "ioredis": "^6.0.0",
     "knex": "3.1.0",
     "kysely": "^0.29.2",
     "mysql2": "^3.0.0",
@@ -76,7 +76,7 @@
     "@opentelemetry/api": "^1.9.0",
     "@opentelemetry/core": "^1.30.0 || ^2.0.0",
     "@opentelemetry/instrumentation": ">=0.200.0 <0.300.0",
-    "ioredis": "^5.0.0",
+    "ioredis": "^5.0.0 || ^6.0.0",
     "knex": "^3.0.0",
     "kysely": "^0.29.0"
   },
diff --git a/tests/_utils/register_driver_test_suite.ts b/tests/_utils/register_driver_test_suite.ts
index 8bfdb4b..730f22a 100644
--- a/tests/_utils/register_driver_test_suite.ts
+++ b/tests/_utils/register_driver_test_suite.ts
@@ -831,7 +831,19 @@ export function registerDriverTestSuite(options: DriverTestSuiteOptions) {
 
   test('renewJobs should keep an active job from being recovered as stalled', async ({
     assert,
+    cleanup,
   }) => {
+    const stalledThreshold = 60_000
+    const realNow = Date.now
+    let clockOffset = 0
+    Date.now = () => realNow() + clockOffset
+    cleanup(() => {
+      Date.now = realNow
+    })
+    const advancePastStalledThreshold = () => {
+      clockOffset += stalledThreshold + 1
+    }
+
     const adapter = await options.createAdapter()
     adapter.setWorkerId('worker-1')
 
@@ -844,25 +856,22 @@ export function registerDriverTestSuite(options: DriverTestSuiteOptions) {
     const job = acquired.find((candidate) => candidate?.id === 'long-running')
     assert.isDefined(job)
 
-    // Both jobs run longer than the 200ms stalled threshold; only one is renewed.
-    // A slow run only makes the control job more stalled, and the renewed job
-    // has a 200ms margin between each renewal and the next recovery.
-    await new Promise((resolve) => setTimeout(resolve, 300))
+    advancePastStalledThreshold()
     assert.equal(await adapter.renewJobs('test-queue', [job!]), 1)
 
-    const first = await adapter.recoverStalledJobs('test-queue', 200, 1, 100)
+    const first = await adapter.recoverStalledJobs('test-queue', stalledThreshold, 1, 100)
 
     // The control job proves the threshold had passed; the renewed job stays active.
     assert.equal(first.recovered, 1)
     assert.equal((await adapter.getJob('long-running', 'test-queue'))!.status, 'active')
     assert.equal((await adapter.getJob('not-renewed', 'test-queue'))!.status, 'pending')
 
-    // 300ms after the first renewal, the job would be stalled again: only the
-    // second renewal, with the same lease, keeps it active.
-    await new Promise((resolve) => setTimeout(resolve, 300))
+    // Past the threshold since the first renewal, only the second renewal,
+    // with the same lease, keeps the job active.
+    advancePastStalledThreshold()
     assert.equal(await adapter.renewJobs('test-queue', [job!]), 1)
 
-    const second = await adapter.recoverStalledJobs('test-queue', 200, 1, 100)
+    const second = await adapter.recoverStalledJobs('test-queue', stalledThreshold, 1, 100)
     assert.equal(second.recovered, 0)
     assert.equal((await adapter.getJob('long-running', 'test-queue'))!.status, 'active')
   })
@@ -2690,30 +2699,30 @@ export function registerDriverTestSuite(options: DriverTestSuiteOptions) {
       name: 'TestJob',
       payload: { n: 1 },
       attempts: 0,
-      dedup: { id: 'TestJob::ext-1', ttl: 400, extend: true },
+      dedup: { id: 'TestJob::ext-1', ttl: 1000, extend: true },
     })
 
-    await new Promise((r) => setTimeout(r, 250))
+    await new Promise((r) => setTimeout(r, 550))
 
     const second = await adapter.pushOn('ext-queue', {
       id: 'ext-uuid-2',
       name: 'TestJob',
       payload: { n: 2 },
       attempts: 0,
-      dedup: { id: 'TestJob::ext-1', ttl: 400, extend: true },
+      dedup: { id: 'TestJob::ext-1', ttl: 1000, extend: true },
     })
     assert.equal(second && typeof second === 'object' && second.outcome, 'extended')
 
-    await new Promise((r) => setTimeout(r, 250))
+    await new Promise((r) => setTimeout(r, 550))
 
-    // Without the extend at T=250, the window would have expired at T=400. With it,
-    // only 250ms of the new 400ms window have passed.
+    // Without the extend at T=550, the window would have expired at T=1000. With it,
+    // only 550ms of the new 1000ms window have passed.
     const third = await adapter.pushOn('ext-queue', {
       id: 'ext-uuid-3',
       name: 'TestJob',
       payload: { n: 3 },
       attempts: 0,
-      dedup: { id: 'TestJob::ext-1', ttl: 400, extend: true },
+      dedup: { id: 'TestJob::ext-1', ttl: 1000, extend: true },
     })
     assert.equal(third && typeof third === 'object' && third.outcome, 'extended')
   })
@@ -2972,17 +2981,17 @@ export function registerDriverTestSuite(options: DriverTestSuiteOptions) {
       name: 'TestJob',
       payload: { version: 1 },
       attempts: 0,
-      dedup: { id: 'TestJob::debounce-1', ttl: 400, extend: true, replace: true },
+      dedup: { id: 'TestJob::debounce-1', ttl: 1000, extend: true, replace: true },
     })
 
-    await new Promise((r) => setTimeout(r, 250))
+    await new Promise((r) => setTimeout(r, 550))
 
     const second = await adapter.pushOn('debounce-queue', {
       id: 'debounce-uuid-2',
       name: 'TestJob',
       payload: { version: 2 },
       attempts: 0,
-      dedup: { id: 'TestJob::debounce-1', ttl: 400, extend: true, replace: true },
+      dedup: { id: 'TestJob::debounce-1', ttl: 1000, extend: true, replace: true },
     })
     assert.equal(second && typeof second === 'object' && second.outcome, 'replaced')
     assert.equal(second && typeof second === 'object' && second.jobId, 'debounce-uuid-1')
@@ -2990,16 +2999,16 @@ export function registerDriverTestSuite(options: DriverTestSuiteOptions) {
     const midRecord = await adapter.getJob('debounce-uuid-1', 'debounce-queue')
     assert.deepEqual(midRecord!.data.payload, { version: 2 })
 
-    // 500ms total elapsed > original 400ms TTL, but the second dispatch reset
-    // the window at T=250. Only 250ms into the new window → still alive.
-    await new Promise((r) => setTimeout(r, 250))
+    // 1100ms total elapsed > original 1000ms TTL, but the second dispatch reset
+    // the window at T=550. Only 550ms into the new window → still alive.
+    await new Promise((r) => setTimeout(r, 550))
 
     const third = await adapter.pushOn('debounce-queue', {
       id: 'debounce-uuid-3',
       name: 'TestJob',
       payload: { version: 3 },
       attempts: 0,
-      dedup: { id: 'TestJob::debounce-1', ttl: 400, extend: true, replace: true },
+      dedup: { id: 'TestJob::debounce-1', ttl: 1000, extend: true, replace: true },
     })
     assert.equal(third && typeof third === 'object' && third.outcome, 'replaced')
     assert.equal(third && typeof third === 'object' && third.jobId, 'debounce-uuid-1')
@@ -3052,11 +3061,11 @@ export function registerDriverTestSuite(options: DriverTestSuiteOptions) {
       name: 'TestJob',
       payload: { n: 1 },
       attempts: 0,
-      dedup: { id: 'TestJob::active-ext-1', ttl: 400, extend: true },
+      dedup: { id: 'TestJob::active-ext-1', ttl: 1000, extend: true },
     })
 
     // Move to active mid-window.
-    await new Promise((r) => setTimeout(r, 250))
+    await new Promise((r) => setTimeout(r, 550))
     const popped = await adapter.popFrom('active-ext-queue')
     assert.equal(popped!.id, 'active-ext-uuid-1')
 
@@ -3067,22 +3076,22 @@ export function registerDriverTestSuite(options: DriverTestSuiteOptions) {
       name: 'TestJob',
       payload: { n: 2 },
       attempts: 0,
-      dedup: { id: 'TestJob::active-ext-1', ttl: 400, extend: true },
+      dedup: { id: 'TestJob::active-ext-1', ttl: 1000, extend: true },
     })
     assert.equal(second && typeof second === 'object' && second.outcome, 'extended')
     assert.equal(second && typeof second === 'object' && second.jobId, 'active-ext-uuid-1')
 
-    // Without the extend, the slot would have expired by now (250 + 250 > 400).
-    // With the extend at T=250, the window restarted; at T=500 only 250ms into
+    // Without the extend, the slot would have expired by now (550 + 550 > 1000).
+    // With the extend at T=550, the window restarted; at T=1100 only 550ms into
     // new window → still blocking.
-    await new Promise((r) => setTimeout(r, 250))
+    await new Promise((r) => setTimeout(r, 550))
 
     const third = await adapter.pushOn('active-ext-queue', {
       id: 'active-ext-uuid-3',
       name: 'TestJob',
       payload: { n: 3 },
       attempts: 0,
-      dedup: { id: 'TestJob::active-ext-1', ttl: 400, extend: true },
+      dedup: { id: 'TestJob::active-ext-1', ttl: 1000, extend: true },
     })
     assert.equal(third && typeof third === 'object' && third.outcome, 'extended')
     assert.equal(third && typeof third === 'object' && third.jobId, 'active-ext-uuid-1')
diff --git a/tests/_utils/register_worker_concurrency_suite.ts b/tests/_utils/register_worker_concurrency_suite.ts
index 56d92ff..9cd099f 100644
--- a/tests/_utils/register_worker_concurrency_suite.ts
+++ b/tests/_utils/register_worker_concurrency_suite.ts
@@ -200,12 +200,15 @@ export function registerWorkerConcurrencyTestSuite(options: WorkerConcurrencyTes
   }) => {
     const jobStartTimes: Map<string, number> = new Map()
     const jobEndTimes: Map<string, number> = new Map()
+    const jobCount = 4
+    const { promise: allJobsStarted, resolve: releaseJobs } = Promise.withResolvers<void>()
+    const sequentialExecutionTimeout = setTimeout(2000, undefined, { ref: false })
 
     class SlowJob extends Job<{ jobId: string }> {
       async execute() {
         jobStartTimes.set(this.payload.jobId, Date.now())
-        // Simulate a slow job (300ms)
-        await setTimeout(300)
+        if (jobStartTimes.size === jobCount) releaseJobs()
+        await Promise.race([allJobsStarted, sequentialExecutionTimeout])
         jobEndTimes.set(this.payload.jobId, Date.now())
       }
     }
@@ -237,7 +240,7 @@ export function registerWorkerConcurrencyTestSuite(options: WorkerConcurrencyTes
       while (cycles < maxCycles) {
         const cycle = await worker.processCycle(['default'])
         cycles++
-        if (cycle?.type === 'idle' && jobEndTimes.size === 4) break
+        if (cycle?.type === 'idle' && jobEndTimes.size === jobCount) break
       }
     })()
 
@@ -279,12 +282,11 @@ export function registerWorkerConcurrencyTestSuite(options: WorkerConcurrencyTes
     await processingPromise
 
     // All 4 jobs should have been executed
-    assert.equal(jobStartTimes.size, 4, 'All 4 jobs should have started')
-    assert.equal(jobEndTimes.size, 4, 'All 4 jobs should have completed')
+    assert.equal(jobStartTimes.size, jobCount, 'All 4 jobs should have started')
+    assert.equal(jobEndTimes.size, jobCount, 'All 4 jobs should have completed')
 
     // Verify concurrent execution: jobs 1, 2, 3 should start BEFORE job 0 ends
-    // If they ran sequentially, job 1 would start after job 0's 300ms execution
-    const job0Start = jobStartTimes.get('job-0')!
+    // If they ran sequentially, job 0 would only end after the sequential execution timeout
     const job0End = jobEndTimes.get('job-0')!
     const job1Start = jobStartTimes.get('job-1')!
     const job2Start = jobStartTimes.get('job-2')!
@@ -292,28 +294,20 @@ export function registerWorkerConcurrencyTestSuite(options: WorkerConcurrencyTes
 
     // Job 1 should start before job 0 ends (proving concurrency)
     assert.isTrue(
-      job1Start < job0End,
-      `Job 1 should start (${job1Start}) before job 0 ends (${job0End}) - concurrent execution`
+      job1Start <= job0End,
+      `Job 1 should start (${job1Start}) no later than job 0 ends (${job0End}) - concurrent execution`
     )
 
     // Job 2 should start before job 0 ends
     assert.isTrue(
-      job2Start < job0End,
-      `Job 2 should start (${job2Start}) before job 0 ends (${job0End}) - concurrent execution`
+      job2Start <= job0End,
+      `Job 2 should start (${job2Start}) no later than job 0 ends (${job0End}) - concurrent execution`
     )
 
     // Job 3 should start before job 0 ends
     assert.isTrue(
-      job3Start < job0End,
-      `Job 3 should start (${job3Start}) before job 0 ends (${job0End}) - concurrent execution`
-    )
-
-    // All jobs should start within a reasonable time window (not sequentially)
-    const maxStartDiff = Math.max(job1Start, job2Start, job3Start) - job0Start
-    assert.isBelow(
-      maxStartDiff,
-      250,
-      `All jobs should start within 250ms of each other (actual: ${maxStartDiff}ms)`
+      job3Start <= job0End,
+      `Job 3 should start (${job3Start}) no later than job 0 ends (${job0End}) - concurrent execution`
     )
   })
 }
diff --git a/tests/adapter.spec.ts b/tests/adapter.spec.ts
index 8b27877..3b42b28 100644
--- a/tests/adapter.spec.ts
+++ b/tests/adapter.spec.ts
@@ -976,10 +976,10 @@ test.group('Adapter | Redis', (group) => {
       .exec()
 
     await adapter.migrate()
-    const firstMembers = await connection.zrange('schedules::due', 0, -1, 'WITHSCORES')
+    const firstMembers = await connection.zrange('schedules::due', 0, '-1', 'WITHSCORES')
 
     await adapter.migrate()
-    const secondMembers = await connection.zrange('schedules::due', 0, -1, 'WITHSCORES')
+    const secondMembers = await connection.zrange('schedules::due', 0, '-1', 'WITHSCORES')
 
     assert.deepEqual(firstMembers, ['idempotent-schedule', nextRunAt.toString()])
     assert.deepEqual(secondMembers, firstMembers)
diff --git a/yarn.lock b/yarn.lock
index 587646a..5e6ffc1 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -64,7 +64,7 @@ __metadata:
     cron-parser: "npm:^5.6.1"
     del-cli: "npm:^7.0.0"
     hot-hook: "npm:^1.0.0"
-    ioredis: "npm:^5.11.1"
+    ioredis: "npm:^6.0.0"
     knex: "npm:3.1.0"
     kysely: "npm:^0.29.2"
     mysql2: "npm:^3.0.0"
@@ -79,7 +79,7 @@ __metadata:
     "@opentelemetry/api": ^1.9.0
     "@opentelemetry/core": ^1.30.0 || ^2.0.0
     "@opentelemetry/instrumentation": ">=0.200.0 <0.300.0"
-    ioredis: ^5.0.0
+    ioredis: ^5.0.0 || ^6.0.0
     knex: ^3.0.0
     kysely: ^0.29.0
   peerDependenciesMeta:
@@ -547,13 +547,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@ioredis/commands@npm:1.10.0":
-  version: 1.10.0
-  resolution: "@ioredis/commands@npm:1.10.0"
-  checksum: 10c0/baf91e62d0e64ef2b5f7ca4413dc2456fe250e87483beac4a1c8ef1fe5ad0d2fcdeb9b89d4556d8ef6c7455c64a964359d729601fdb06b2f4c76c35dd59afa99
-  languageName: node
-  linkType: hard
-
 "@ioredis/commands@npm:1.5.1":
   version: 1.5.1
   resolution: "@ioredis/commands@npm:1.5.1"
@@ -561,6 +554,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@ioredis/commands@npm:2.0.0":
+  version: 2.0.0
+  resolution: "@ioredis/commands@npm:2.0.0"
+  checksum: 10c0/2fb5edb9782790c24a375cc78bd69d45ac6c268d7d7ed8e534f2d4ecc28707bde9882a04eecd68be369ae784801bf93fa267b9a76f86418b252a08f341934e35
+  languageName: node
+  linkType: hard
+
 "@isaacs/fs-minipass@npm:^4.0.0":
   version: 4.0.1
   resolution: "@isaacs/fs-minipass@npm:4.0.1"
@@ -3414,18 +3414,17 @@ __metadata:
   languageName: node
   linkType: hard
 
-"ioredis@npm:^5.11.1":
-  version: 5.11.1
-  resolution: "ioredis@npm:5.11.1"
+"ioredis@npm:^6.0.0":
+  version: 6.0.0
+  resolution: "ioredis@npm:6.0.0"
   dependencies:
-    "@ioredis/commands": "npm:1.10.0"
+    "@ioredis/commands": "npm:2.0.0"
     cluster-key-slot: "npm:1.1.1"
     debug: "npm:4.4.3"
     denque: "npm:2.1.0"
     redis-errors: "npm:1.2.0"
-    redis-parser: "npm:3.0.0"
     standard-as-callback: "npm:2.1.0"
-  checksum: 10c0/a8b27043cf2c045dfc93f40a32ce24cf9f8b57799a37f4234c4b925c365ccf131629590f94a512f546fda2ba8ed034009c94c4933ecd44c50bc166636d929fd6
+  checksum: 10c0/6f74e1d298440c0d814e6bf9b3acdb0991d4c1862d3fa64c3828668bcc306823f7845710abdc5eab7986a35d86ec8c86c4bb9c9c7d727636d385ecb2cd40abd7
   languageName: node
   linkType: hard
 
@@ -5021,7 +5020,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"redis-parser@npm:3.0.0, redis-parser@npm:^3.0.0":
+"redis-parser@npm:^3.0.0":
   version: 3.0.0
   resolution: "redis-parser@npm:3.0.0"
   dependencies: