diff --git a/test/client-node-max-header-size.js b/test/client-node-max-header-size.js
index 575305eca68..9d5ab0ed90d 100644
--- a/test/client-node-max-header-size.js
+++ b/test/client-node-max-header-size.js
@@ -21,7 +21,10 @@ describe("Node.js' --max-http-header-size cli option", () => {
     await once(server, 'listening')
   })
 
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   test("respect Node.js' --max-http-header-size", async (t) => {
     t = tspl(t, { plan: 6 })
diff --git a/test/client-request.js b/test/client-request.js
index 15a3b1a734f..d367435eeff 100644
--- a/test/client-request.js
+++ b/test/client-request.js
@@ -22,7 +22,10 @@ test('request dump head', async (t) => {
     res.flushHeaders()
     res.write('hello'.repeat(100))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -56,7 +59,10 @@ test('request dump big', async (t) => {
       // Do nothing...
     }
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -90,7 +96,10 @@ test('request dump', async (t) => {
     res.setHeader('content-length', 5)
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -120,7 +129,10 @@ test('request dump with abort signal', async (t) => {
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
     res.write('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -158,7 +170,10 @@ test('request dump with POJO as invalid signal', async (t) => {
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
     res.write('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -193,7 +208,10 @@ test('request dump with aborted signal', async (t) => {
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
     res.write('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -231,7 +249,10 @@ test('request hwm', async (t) => {
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
     res.write('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -259,7 +280,10 @@ test('request abort before headers', async (t) => {
     res.end('hello')
     signal.emit('abort')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -296,7 +320,10 @@ test('request body destroyed on invalid callback', async (t) => {
 
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -327,7 +354,10 @@ test('trailers', async (t) => {
     res.addTrailers({ 'Content-MD5': 'test' })
     res.end()
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -365,7 +395,10 @@ test('destroy socket abruptly', async (t) => {
     // therefore we delay it to the next event loop run.
     setImmediate(socket.destroy.bind(socket))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
   const client = new Client(`http://localhost:${server.address().port}`)
@@ -407,7 +440,10 @@ test('destroy socket abruptly with keep-alive', async (t) => {
     // therefore we delay it to the next event loop run.
     setImmediate(socket.destroy.bind(socket))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
   const client = new Client(`http://localhost:${server.address().port}`)
@@ -441,7 +477,10 @@ test('request json', async (t) => {
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
     res.end(JSON.stringify(obj))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -464,7 +503,10 @@ test('request long multibyte json', async (t) => {
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
     res.end(JSON.stringify(obj))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -487,7 +529,10 @@ test('request text', async (t) => {
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
     res.end(JSON.stringify(obj))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -577,7 +622,10 @@ describe('headers', () => {
       serverAddress = `localhost:${server.address().port}`
     })
 
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections()
+      server.close()
+    })
 
     test('empty host header', async (t) => {
       t = tspl(t, { plan: 4 })
@@ -617,7 +665,10 @@ describe('headers', () => {
       serverAddress = `localhost:${server.address().port}`
     })
 
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections()
+      server.close()
+    })
 
     test('invalid host header', async (t) => {
       t = tspl(t, { plan: 1 })
@@ -669,7 +720,10 @@ test('request long multibyte text', async (t) => {
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
     res.end(JSON.stringify(obj))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -693,7 +747,10 @@ test('request blob', async (t) => {
     res.setHeader('Content-Type', 'application/json')
     res.end(JSON.stringify(obj))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -719,7 +776,10 @@ test('request arrayBuffer', async (t) => {
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
     res.end(JSON.stringify(obj))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -745,7 +805,10 @@ test('request bytes', async (t) => {
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
     res.end(JSON.stringify(obj))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -771,7 +834,10 @@ test('request body', async (t) => {
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
     res.end(JSON.stringify(obj))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -803,7 +869,10 @@ test('request post body no missing data', async (t) => {
     t.strictEqual(ret, 'asd')
     res.end()
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -837,7 +906,10 @@ test('request post body no extra data handler', async (t) => {
     t.strictEqual(ret, 'asd')
     res.end()
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -872,7 +944,10 @@ test('request with onInfo callback', async (t) => {
     res.setHeader('Content-Type', 'application/json')
     res.end(JSON.stringify({ foo: 'bar' }))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -899,7 +974,10 @@ test('request with onInfo callback but socket is destroyed before end of respons
     response = res
     res.writeProcessing()
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -943,7 +1021,10 @@ test('request onInfo callback headers parsing', async (t) => {
     ]
     socket.end(lines.join('\r\n'))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
 
@@ -979,7 +1060,10 @@ test('request raw responseHeaders', async (t) => {
     ]
     socket.end(lines.join('\r\n'))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
 
@@ -1006,7 +1090,10 @@ test('request formData', async (t) => {
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
     res.end(JSON.stringify(obj))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -1035,7 +1122,10 @@ test('request text2', async (t) => {
   const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
     res.end(JSON.stringify(obj))
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -1092,7 +1182,10 @@ test('request with FormData body', async (t) => {
 
     return res.end()
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -1122,7 +1215,10 @@ test('request post body Buffer from string', async (t) => {
     t.strictEqual(ret, 'abcdefghijklmnopqrstuvwxyz')
     res.end()
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -1153,7 +1249,10 @@ test('request post body Buffer from buffer', async (t) => {
     t.strictEqual(ret, 'ijklmnopqrstuvwx')
     res.end()
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -1184,7 +1283,10 @@ test('request post body Uint8Array', async (t) => {
     t.strictEqual(ret, 'ijklmnopqrstuvwx')
     res.end()
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -1215,7 +1317,10 @@ test('request post body Uint32Array', async (t) => {
     t.strictEqual(ret, 'ijklmnopqrstuvwx')
     res.end()
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -1246,7 +1351,10 @@ test('request post body Float64Array', async (t) => {
     t.strictEqual(ret, 'ijklmnopqrstuvwx')
     res.end()
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -1277,7 +1385,10 @@ test('request post body BigUint64Array', async (t) => {
     t.strictEqual(ret, 'ijklmnopqrstuvwx')
     res.end()
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
@@ -1308,7 +1419,10 @@ test('request post body DataView', async (t) => {
     t.strictEqual(ret, 'ijklmnopqrstuvwx')
     res.end()
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   server.listen(0, async () => {
     const client = new Client(`http://localhost:${server.address().port}`)
diff --git a/test/env-http-proxy-agent-nodejs-bundle.js b/test/env-http-proxy-agent-nodejs-bundle.js
index 57aad4960f9..47c2649ff42 100644
--- a/test/env-http-proxy-agent-nodejs-bundle.js
+++ b/test/env-http-proxy-agent-nodejs-bundle.js
@@ -30,7 +30,10 @@ describe('EnvHttpProxyAgent and setGlobalDispatcher', () => {
     server.on('error', err => { console.log('Server error', err) })
     server.listen(0)
     await once(server, 'listening')
-    t.after(() => { server.close() })
+    t.after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     const proxy = http.createServer({ joinDuplicateHeaders: true })
     proxy.on('connect', (req, clientSocket, head) => {
@@ -60,7 +63,10 @@ describe('EnvHttpProxyAgent and setGlobalDispatcher', () => {
 
     proxy.listen(0)
     await once(proxy, 'listening')
-    t.after(() => { proxy.close() })
+    t.after(() => {
+      proxy.closeAllConnections?.()
+      proxy.close()
+    })
 
     // Use setGlobalDispatcher and EnvHttpProxyAgent from Node.js
     // and make sure that they work together.
diff --git a/test/fetch/client-node-max-header-size.js b/test/fetch/client-node-max-header-size.js
index a6d9a2db029..744729b6371 100644
--- a/test/fetch/client-node-max-header-size.js
+++ b/test/fetch/client-node-max-header-size.js
@@ -20,7 +20,10 @@ describe('fetch respects --max-http-header-size', () => {
     await once(server, 'listening')
   })
 
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   test("respect Node.js' --max-http-header-size", (t, done) => {
     t.plan(6)
diff --git a/test/fetch/encoding.js b/test/fetch/encoding.js
index cfaabc4dd6e..ec07a4bdbd8 100644
--- a/test/fetch/encoding.js
+++ b/test/fetch/encoding.js
@@ -50,6 +50,7 @@ describe('content-encoding handling', () => {
   })
 
   after(() => {
+    server.closeAllConnections?.()
     server.close()
   })
 
@@ -112,6 +113,7 @@ describe('content-encoding chain limit', () => {
   })
 
   after(() => {
+    server.closeAllConnections?.()
     server.close()
   })
 
diff --git a/test/issue-4244.js b/test/issue-4244.js
index f8bea892153..489557fe495 100644
--- a/test/issue-4244.js
+++ b/test/issue-4244.js
@@ -12,7 +12,10 @@ describe('Agent should close inactive clients', () => {
       res.end('ok')
     }).listen(0)
 
-    t.after(() => server.close())
+    t.after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     let p
     const agent = new Agent({
diff --git a/test/max-response-size.js b/test/max-response-size.js
index 648a4cb08a0..c1b39c98204 100644
--- a/test/max-response-size.js
+++ b/test/max-response-size.js
@@ -10,7 +10,10 @@ describe('max response size', async (t) => {
     t = tspl(t, { plan: 3 })
 
     const server = createServer({ joinDuplicateHeaders: true })
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     server.on('request', (req, res) => {
       res.end('hello')
@@ -40,7 +43,10 @@ describe('max response size', async (t) => {
     t = tspl(t, { plan: 3 })
 
     const server = createServer({ joinDuplicateHeaders: true })
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     server.on('request', (req, res) => {
       res.end()
@@ -70,7 +76,10 @@ describe('max response size', async (t) => {
     t = tspl(t, { plan: 3 })
 
     const server = createServer({ joinDuplicateHeaders: true })
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     server.on('request', (req, res) => {
       res.end('hello')
diff --git a/test/mock-agent.js b/test/mock-agent.js
index a0df6413a4e..bb3d2afb9f7 100644
--- a/test/mock-agent.js
+++ b/test/mock-agent.js
@@ -273,7 +273,10 @@ test('MockAgent - [kClients] should match encapsulated agent', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -302,7 +305,10 @@ test('MockAgent - basic intercept with MockAgent.request', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -345,7 +351,10 @@ test('MockAgent - basic intercept with request', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -387,7 +396,10 @@ test('MockAgent - should support local agents', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -432,7 +444,10 @@ test('MockAgent - should support specifying custom agents to mock', async (t) =>
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -478,7 +493,10 @@ test('MockAgent - basic Client intercept with request', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -522,7 +540,10 @@ test('MockAgent - basic intercept with multiple pools', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -573,7 +594,10 @@ test('MockAgent - should handle multiple responses for an interceptor', async (t
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -636,7 +660,10 @@ test('MockAgent - should call original Pool dispatch if request not found', asyn
     res.setHeader('content-type', 'text/plain')
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -665,7 +692,10 @@ test('MockAgent - should call original Client dispatch if request not found', as
     res.setHeader('content-type', 'text/plain')
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -693,7 +723,10 @@ test('MockAgent - should handle string responses', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -756,7 +789,10 @@ test('MockAgent - handle delays to simulate work', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -793,7 +829,10 @@ test('MockAgent - should persist requests', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1053,7 +1092,10 @@ test('MockAgent - handle persists with delayed requests', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1098,7 +1140,10 @@ test('MockAgent - calling close on a mock pool should not affect other mock pool
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1155,7 +1200,10 @@ test('MockAgent - close removes all registered mock clients', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1210,7 +1258,10 @@ test('MockAgent - close removes all registered mock pools', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1243,7 +1294,10 @@ test('MockAgent - should handle replyWithError', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1271,7 +1325,10 @@ test('MockAgent - should support setting a reply to respond a set amount of time
     res.setHeader('content-type', 'text/plain')
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1321,7 +1378,10 @@ test('MockAgent - persist overrides times', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1376,7 +1436,10 @@ test('MockAgent - matcher should not find mock dispatch if path is of unsupporte
     t.assert.strictEqual(req.method, 'GET')
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1409,7 +1472,10 @@ test('MockAgent - should match path with regex', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1454,7 +1520,10 @@ test('MockAgent - should match path with function', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1487,7 +1556,10 @@ test('MockAgent - should match method with regex', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1520,7 +1592,10 @@ test('MockAgent - should match method with function', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1553,7 +1628,10 @@ test('MockAgent - should match body with regex', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1588,7 +1666,10 @@ test('MockAgent - should match body with function', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1622,7 +1703,10 @@ test('MockAgent - should match headers with string', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1694,7 +1778,10 @@ test('MockAgent - should match headers with regex', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1766,7 +1853,10 @@ test('MockAgent - should match headers with function', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1839,7 +1929,10 @@ test('MockAgent - should match url with regex', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1872,7 +1965,10 @@ test('MockAgent - should match url with function', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1905,7 +2001,10 @@ test('MockAgent - handle default reply headers', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1942,7 +2041,10 @@ test('MockAgent - handle default reply trailers', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -1979,7 +2081,10 @@ test('MockAgent - return calculated content-length if specified', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2016,7 +2121,10 @@ test('MockAgent - return calculated content-length for object response if specif
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2054,7 +2162,10 @@ test('MockAgent - should activate and deactivate mock clients', async (t) => {
     res.setHeader('content-type', 'text/plain')
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2115,7 +2226,10 @@ test('MockAgent - enableNetConnect should allow all original dispatches to be ca
     res.setHeader('content-type', 'text/plain')
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2152,7 +2266,10 @@ test('MockAgent - enableNetConnect with a host string should allow all original
     res.setHeader('content-type', 'text/plain')
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2189,7 +2306,10 @@ test('MockAgent - enableNetConnect when called with host string multiple times s
     res.setHeader('content-type', 'text/plain')
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2227,7 +2347,10 @@ test('MockAgent - enableNetConnect with a host regex should allow all original d
     res.setHeader('content-type', 'text/plain')
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2264,7 +2387,10 @@ test('MockAgent - enableNetConnect with a function should allow all original dis
     res.setHeader('content-type', 'text/plain')
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2315,7 +2441,10 @@ test('MockAgent - enableNetConnect should throw if dispatch not matched for path
     t.assert.fail('should not be called')
     res.end('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2345,7 +2474,10 @@ test('MockAgent - enableNetConnect should throw if dispatch not matched for meth
     t.assert.fail('should not be called')
     res.end('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2375,7 +2507,10 @@ test('MockAgent - enableNetConnect should throw if dispatch not matched for body
     t.assert.fail('should not be called')
     res.end('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2407,7 +2542,10 @@ test('MockAgent - enableNetConnect should throw if dispatch not matched for head
     t.assert.fail('should not be called')
     res.end('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2445,7 +2583,10 @@ test('MockAgent - disableNetConnect should throw if dispatch not found by net co
     res.setHeader('content-type', 'text/plain')
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2475,7 +2616,10 @@ test('MockAgent - headers function interceptor', async (t) => {
     t.assert.fail('should not be called')
     res.end('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2536,7 +2680,10 @@ test('MockAgent - clients are not garbage collected', async (t) => {
     t.assert.fail('should not be called')
     res.end('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2794,7 +2941,10 @@ test('MockAgent - Sending ReadableStream body', async (t) => {
   })
 
   after(() => mockAgent.close())
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
@@ -2858,7 +3008,10 @@ test('MockAgent - headers should be array of strings (fetch)', async (t) => {
       res.end('should not be called')
       t.assert.fail('should not be called')
     })
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     await once(server.listen(0), 'listening')
 
@@ -2902,7 +3055,10 @@ test('MockAgent - should not accept non-standard search parameters when acceptNo
     res.setHeader('content-type', 'text/plain')
     res.end('(non-intercepted) response from server')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await once(server.listen(0), 'listening')
 
diff --git a/test/mock-client.js b/test/mock-client.js
index 6cdd3df10f4..e89bc516e52 100644
--- a/test/mock-client.js
+++ b/test/mock-client.js
@@ -202,7 +202,10 @@ test('MockClient - should be able to set as globalDispatcher', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
 
@@ -237,7 +240,10 @@ test('MockClient - should support query params', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
 
@@ -277,7 +283,10 @@ test('MockClient - should intercept query params with hardcoded path', async (t)
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
 
@@ -316,7 +325,10 @@ test('MockClient - should intercept query params regardless of key ordering', as
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
 
@@ -363,7 +375,10 @@ test('MockClient - should be able to use as a local dispatcher', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
 
@@ -398,7 +413,10 @@ test('MockClient - basic intercept with MockClient.request', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
 
@@ -441,7 +459,10 @@ test('MockClient - cleans mocks', async (t) => {
     res.setHeader('content-type', 'text/plain')
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
 
diff --git a/test/mock-pool.js b/test/mock-pool.js
index ec00a50cbea..ca4805dc434 100644
--- a/test/mock-pool.js
+++ b/test/mock-pool.js
@@ -188,7 +188,10 @@ test('MockPool - should be able to set as globalDispatcher', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
 
@@ -223,7 +226,10 @@ test('MockPool - should be able to use as a local dispatcher', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
 
@@ -258,7 +264,10 @@ test('MockPool - basic intercept with MockPool.request', async (t) => {
     res.end('should not be called')
     t.assert.fail('should not be called')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
 
@@ -363,7 +372,10 @@ test('MockPool - cleans mocks', async (t) => {
     res.setHeader('content-type', 'text/plain')
     res.end('hello')
   })
-  after(() => server.close())
+  after(() => {
+    server.closeAllConnections?.()
+    server.close()
+  })
 
   await promisify(server.listen.bind(server))(0)
 
diff --git a/test/no-strict-content-length.js b/test/no-strict-content-length.js
index 4779bfcd862..3b16d2eeb72 100644
--- a/test/no-strict-content-length.js
+++ b/test/no-strict-content-length.js
@@ -31,7 +31,10 @@ describe('strictContentLength: false', () => {
     const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
       res.end()
     })
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     server.listen(0, () => {
       const client = new Client(`http://localhost:${server.address().port}`, {
@@ -149,7 +152,10 @@ describe('strictContentLength: false', () => {
     const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
       res.end()
     })
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     server.listen(0, () => {
       const client = new Client(`http://localhost:${server.address().port}`, {
@@ -186,7 +192,10 @@ describe('strictContentLength: false', () => {
     const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
       res.end()
     })
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     server.listen(0, () => {
       const client = new Client(`http://localhost:${server.address().port}`, {
@@ -223,7 +232,10 @@ describe('strictContentLength: false', () => {
     const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
       res.end()
     })
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     server.listen(0, () => {
       const client = new Client(`http://localhost:${server.address().port}`, {
@@ -260,7 +272,10 @@ describe('strictContentLength: false', () => {
     const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
       res.end()
     })
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     server.listen(0, () => {
       const client = new Client(`http://localhost:${server.address().port}`, {
@@ -297,7 +312,10 @@ describe('strictContentLength: false', () => {
     const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
       res.end()
     })
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     server.listen(0, () => {
       const client = new Client(`http://localhost:${server.address().port}`, {
@@ -333,7 +351,10 @@ describe('strictContentLength: false', () => {
     const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
       res.end()
     })
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     server.listen(0, () => {
       const client = new Client(`http://localhost:${server.address().port}`, {
diff --git a/test/request.js b/test/request.js
index c7adc234bcd..6166a95e079 100644
--- a/test/request.js
+++ b/test/request.js
@@ -202,7 +202,10 @@ describe('DispatchOptions#maxRedirections', () => {
       t.ok('request received')
       res.end('hello world')
     })
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
     await new Promise((resolve) => server.listen(0, resolve))
 
     const res = await request({
@@ -241,7 +244,10 @@ describe('DispatchOptions#reset', () => {
       res.end('hello')
     })
 
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     await new Promise((resolve, reject) => {
       server.listen(0, (err) => {
@@ -268,7 +274,10 @@ describe('DispatchOptions#reset', () => {
       res.end('hello')
     })
 
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     await new Promise((resolve, reject) => {
       server.listen(0, (err) => {
@@ -295,7 +304,10 @@ describe('DispatchOptions#reset', () => {
       res.end('hello')
     })
 
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     await new Promise((resolve, reject) => {
       server.listen(0, (err) => {
@@ -329,7 +341,10 @@ describe('Should include headers from iterable objects', scope => {
     const headers = new globalThis.Headers()
     headers.set('hello', 'world')
 
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     await new Promise((resolve, reject) => {
       server.listen(0, (err) => {
@@ -360,7 +375,10 @@ describe('Should include headers from iterable objects', scope => {
     const headers = new Map()
     headers.set('hello', 'world')
 
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     await new Promise((resolve, reject) => {
       server.listen(0, (err) => {
@@ -394,7 +412,10 @@ describe('Should include headers from iterable objects', scope => {
       }
     }
 
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     await new Promise((resolve, reject) => {
       server.listen(0, (err) => {
@@ -424,7 +445,10 @@ describe('Should include headers from iterable objects', scope => {
       }
     }
 
-    after(() => server.close())
+    after(() => {
+      server.closeAllConnections?.()
+      server.close()
+    })
 
     await new Promise((resolve, reject) => {
       server.listen(0, (err) => {
diff --git a/test/snapshot-testing.js b/test/snapshot-testing.js
index 10f8439f51e..8bb6c815c01 100644
--- a/test/snapshot-testing.js
+++ b/test/snapshot-testing.js
@@ -47,7 +47,10 @@ async function setupServer (server) {
 
 function setupCleanup (t, resources) {
   if (resources.server) {
-    t.after(() => resources.server.close())
+    t.after(() => {
+      resources.server.closeAllConnections?.()
+      resources.server.close()
+    })
   }
   if (resources.snapshotPath) {
     t.after(() => unlink(resources.snapshotPath).catch(() => {}))