diff --git a/test/lib/custom-assertions.js b/test/lib/custom-assertions.js
index 3fa0ddbddf..6b4a1eba1f 100644
--- a/test/lib/custom-assertions.js
+++ b/test/lib/custom-assertions.js
@@ -33,10 +33,18 @@ function assertCLMAttrs({ segments, enabled: clmEnabled, skipFull = false }) {
     const attrs = segment.segment.getAttributes()
     if (clmEnabled) {
       assert.equal(attrs['code.function'], segment.name, 'should have appropriate code.function')
-      assert.ok(
-        attrs['code.filepath'].endsWith(segment.filepath),
-        'should have appropriate code.filepath'
-      )
+      if (segment.filepath instanceof RegExp) {
+        assert.match(
+          attrs['code.filepath'],
+          segment.filepath,
+          'should have appropriate code.filepath'
+        )
+      } else {
+        assert.ok(
+          attrs['code.filepath'].endsWith(segment.filepath),
+          'should have appropriate code.filepath'
+        )
+      }
 
       if (!skipFull) {
         assert.equal(typeof attrs['code.lineno'], 'number', 'lineno should be a number')
diff --git a/test/versioned/fastify/add-hook.tap.js b/test/versioned/fastify/add-hook.tap.js
deleted file mode 100644
index 2b489904ff..0000000000
--- a/test/versioned/fastify/add-hook.tap.js
+++ /dev/null
@@ -1,178 +0,0 @@
-/*
- * Copyright 2021 New Relic Corporation. All rights reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-'use strict'
-
-const tap = require('tap')
-const helper = require('../../lib/agent_helper')
-require('../../lib/metrics_helper')
-const common = require('./common')
-
-// all of these events fire before the route handler
-// See: https://www.fastify.io/docs/latest/Lifecycle/
-// for more info on sequence
-const REQUEST_HOOKS = ['onRequest', 'preParsing', 'preValidation', 'preHandler']
-
-// these events fire after the route
-// handler. they are in separate arrays
-// for segment relationship assertions later
-const AFTER_HANDLER_HOOKS = ['preSerialization', 'onSend']
-
-// the onResponse hook fires after a response
-// is received by client which is out of context
-// of the transaction
-const AFTER_TX_HOOKS = ['onResponse']
-
-const ALL_HOOKS = [...REQUEST_HOOKS, ...AFTER_HANDLER_HOOKS, ...AFTER_TX_HOOKS]
-
-/**
- * Helper to return the list of expected segments
- *
- * @param {Array} hooks lifecyle hook names to build segment names from
- * @returns {Array} formatted list of expected segments
- */
-function getExpectedSegments(hooks) {
-  return hooks.map((hookName) => {
-    return `Nodejs/Middleware/Fastify/${hookName}/testHook`
-  })
-}
-
-tap.test('fastify hook instrumentation', (t) => {
-  t.autoend()
-  t.beforeEach(() => {
-    const agent = helper.instrumentMockedAgent()
-    const fastify = require('fastify')()
-    common.setupRoutes(fastify)
-    t.context.agent = agent
-    t.context.fastify = fastify
-  })
-
-  t.afterEach(() => {
-    const { fastify, agent } = t.context
-    helper.unloadAgent(agent)
-    fastify.close()
-  })
-
-  t.test('non-error hooks', async function nonErrorHookTest(t) {
-    const { fastify, agent } = t.context
-
-    // setup hooks
-    const ok = ALL_HOOKS.reduce((all, hookName) => {
-      all[hookName] = false
-      return all
-    }, {})
-
-    ALL_HOOKS.forEach((hookName) => {
-      fastify.addHook(hookName, function testHook(...args) {
-        // lifecycle signatures vary between the events
-        // the last arg is always the next function though
-        const next = args[args.length - 1]
-        ok[hookName] = true
-        next()
-      })
-    })
-
-    agent.on('transactionFinished', (transaction) => {
-      t.equal(
-        'WebFrameworkUri/Fastify/GET//add-hook',
-        transaction.getName(),
-        `transaction name matched`
-      )
-      // all the hooks are siblings of the route handler
-      // except the AFTER_HANDLER_HOOKS which are children of the route handler
-      let expectedSegments
-      if (helper.isSecurityAgentEnabled(agent)) {
-        expectedSegments = [
-          'WebTransaction/WebFrameworkUri/Fastify/GET//add-hook',
-          [
-            'Nodejs/Middleware/Fastify/onRequest/<anonymous>',
-            [
-              ...getExpectedSegments(REQUEST_HOOKS),
-              'Nodejs/Middleware/Fastify/routeHandler//add-hook',
-              getExpectedSegments(AFTER_HANDLER_HOOKS)
-            ]
-          ]
-        ]
-      } else {
-        expectedSegments = [
-          'WebTransaction/WebFrameworkUri/Fastify/GET//add-hook',
-          [
-            ...getExpectedSegments(REQUEST_HOOKS),
-            'Nodejs/Middleware/Fastify/routeHandler//add-hook',
-            getExpectedSegments(AFTER_HANDLER_HOOKS)
-          ]
-        ]
-      }
-      t.assertSegments(transaction.trace.root, expectedSegments)
-    })
-
-    await fastify.listen({ port: 0 })
-    const address = fastify.server.address()
-    const result = await common.makeRequest(address, '/add-hook')
-    t.same(result, { hello: 'world' })
-
-    // verify every hook was called after response
-    for (const [hookName, isOk] of Object.entries(ok)) {
-      t.equal(isOk, true, `${hookName} captured`)
-    }
-    t.end()
-  })
-
-  t.test('error hook', async function errorHookTest(t) {
-    const { fastify, agent } = t.context
-
-    const hookName = 'onError'
-    let ok = false
-
-    fastify.addHook(hookName, function testHook(req, reply, err, next) {
-      t.equal(err.message, 'test onError hook', 'error message correct')
-      ok = true
-      next()
-    })
-
-    agent.on('transactionFinished', (transaction) => {
-      t.equal(
-        'WebFrameworkUri/Fastify/GET//error',
-        transaction.getName(),
-        `transaction name matched`
-      )
-      // all the hooks are siblings of the route handler
-      let expectedSegments
-      if (helper.isSecurityAgentEnabled(agent)) {
-        expectedSegments = [
-          'WebTransaction/WebFrameworkUri/Fastify/GET//error',
-          [
-            'Nodejs/Middleware/Fastify/onRequest/<anonymous>',
-            [
-              'Nodejs/Middleware/Fastify/errorRoute//error',
-              [`Nodejs/Middleware/Fastify/${hookName}/testHook`]
-            ]
-          ]
-        ]
-      } else {
-        expectedSegments = [
-          'WebTransaction/WebFrameworkUri/Fastify/GET//error',
-          [
-            'Nodejs/Middleware/Fastify/errorRoute//error',
-            [`Nodejs/Middleware/Fastify/${hookName}/testHook`]
-          ]
-        ]
-      }
-
-      t.assertSegments(transaction.trace.root, expectedSegments)
-    })
-
-    await fastify.listen({ port: 0 })
-    const address = fastify.server.address()
-    const result = await common.makeRequest(address, '/error')
-    t.ok(ok)
-    t.same(result, {
-      statusCode: 500,
-      error: 'Internal Server Error',
-      message: 'test onError hook'
-    })
-    t.end()
-  })
-})
diff --git a/test/versioned/fastify/add-hook.test.js b/test/versioned/fastify/add-hook.test.js
new file mode 100644
index 0000000000..b836dfcde3
--- /dev/null
+++ b/test/versioned/fastify/add-hook.test.js
@@ -0,0 +1,187 @@
+/*
+ * Copyright 2024 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+const test = require('node:test')
+const assert = require('node:assert')
+
+const { removeModules } = require('../../lib/cache-buster')
+const { assertSegments, match } = require('../../lib/custom-assertions')
+const helper = require('../../lib/agent_helper')
+const common = require('./common')
+
+// all of these events fire before the route handler
+// See: https://www.fastify.io/docs/latest/Lifecycle/
+// for more info on sequence
+const REQUEST_HOOKS = ['onRequest', 'preParsing', 'preValidation', 'preHandler']
+
+// these events fire after the route
+// handler. they are in separate arrays
+// for segment relationship assertions later
+const AFTER_HANDLER_HOOKS = ['preSerialization', 'onSend']
+
+// the onResponse hook fires after a response
+// is received by client which is out of context
+// of the transaction
+const AFTER_TX_HOOKS = ['onResponse']
+
+const ALL_HOOKS = [...REQUEST_HOOKS, ...AFTER_HANDLER_HOOKS, ...AFTER_TX_HOOKS]
+
+/**
+ * Helper to return the list of expected segments
+ *
+ * @param {Array} hooks lifecyle hook names to build segment names from
+ * @returns {Array} formatted list of expected segments
+ */
+function getExpectedSegments(hooks) {
+  return hooks.map((hookName) => {
+    return `Nodejs/Middleware/Fastify/${hookName}/testHook`
+  })
+}
+
+test.beforeEach((ctx) => {
+  ctx.nr = {}
+  ctx.nr.agent = helper.instrumentMockedAgent()
+
+  const fastify = require('fastify')()
+  common.setupRoutes(fastify)
+  ctx.nr.fastify = fastify
+})
+
+test.afterEach((ctx) => {
+  helper.unloadAgent(ctx.nr.agent)
+  ctx.nr.fastify.close()
+  removeModules(['fastify'])
+})
+
+test('non-error hooks', async (t) => {
+  const { fastify, agent } = t.nr
+
+  // setup hooks
+  const ok = ALL_HOOKS.reduce((all, hookName) => {
+    all[hookName] = false
+    return all
+  }, {})
+
+  ALL_HOOKS.forEach((hookName) => {
+    fastify.addHook(hookName, function testHook(...args) {
+      // lifecycle signatures vary between the events
+      // the last arg is always the next function though
+      const next = args[args.length - 1]
+      ok[hookName] = true
+      next()
+    })
+  })
+
+  let txPassed = false
+  agent.on('transactionFinished', (transaction) => {
+    assert.equal(
+      'WebFrameworkUri/Fastify/GET//add-hook',
+      transaction.getName(),
+      `transaction name matched`
+    )
+    // all the hooks are siblings of the route handler
+    // except the AFTER_HANDLER_HOOKS which are children of the route handler
+    let expectedSegments
+    if (helper.isSecurityAgentEnabled(agent)) {
+      expectedSegments = [
+        'WebTransaction/WebFrameworkUri/Fastify/GET//add-hook',
+        [
+          'Nodejs/Middleware/Fastify/onRequest/<anonymous>',
+          [
+            ...getExpectedSegments(REQUEST_HOOKS),
+            'Nodejs/Middleware/Fastify/routeHandler//add-hook',
+            getExpectedSegments(AFTER_HANDLER_HOOKS)
+          ]
+        ]
+      ]
+    } else {
+      expectedSegments = [
+        'WebTransaction/WebFrameworkUri/Fastify/GET//add-hook',
+        [
+          ...getExpectedSegments(REQUEST_HOOKS),
+          'Nodejs/Middleware/Fastify/routeHandler//add-hook',
+          getExpectedSegments(AFTER_HANDLER_HOOKS)
+        ]
+      ]
+    }
+    assertSegments(transaction.trace.root, expectedSegments)
+
+    txPassed = true
+  })
+
+  await fastify.listen({ port: 0 })
+  const address = fastify.server.address()
+  const result = await common.makeRequest(address, '/add-hook')
+  match(result, { hello: 'world' })
+
+  // verify every hook was called after response
+  for (const [hookName, isOk] of Object.entries(ok)) {
+    assert.equal(isOk, true, `${hookName} captured`)
+  }
+
+  assert.equal(txPassed, true, 'transactionFinished assertions passed')
+})
+
+test('error hook', async function errorHookTest(t) {
+  const { fastify, agent } = t.nr
+
+  const hookName = 'onError'
+  let ok = false
+
+  fastify.addHook(hookName, function testHook(req, reply, err, next) {
+    assert.equal(err.message, 'test onError hook', 'error message correct')
+    ok = true
+    next()
+  })
+
+  let txPassed = false
+  agent.on('transactionFinished', (transaction) => {
+    assert.equal(
+      'WebFrameworkUri/Fastify/GET//error',
+      transaction.getName(),
+      `transaction name matched`
+    )
+    // all the hooks are siblings of the route handler
+    let expectedSegments
+    if (helper.isSecurityAgentEnabled(agent)) {
+      expectedSegments = [
+        'WebTransaction/WebFrameworkUri/Fastify/GET//error',
+        [
+          'Nodejs/Middleware/Fastify/onRequest/<anonymous>',
+          [
+            'Nodejs/Middleware/Fastify/errorRoute//error',
+            [`Nodejs/Middleware/Fastify/${hookName}/testHook`]
+          ]
+        ]
+      ]
+    } else {
+      expectedSegments = [
+        'WebTransaction/WebFrameworkUri/Fastify/GET//error',
+        [
+          'Nodejs/Middleware/Fastify/errorRoute//error',
+          [`Nodejs/Middleware/Fastify/${hookName}/testHook`]
+        ]
+      ]
+    }
+
+    assertSegments(transaction.trace.root, expectedSegments)
+
+    txPassed = true
+  })
+
+  await fastify.listen({ port: 0 })
+  const address = fastify.server.address()
+  const result = await common.makeRequest(address, '/error')
+  assert.ok(ok)
+  match(result, {
+    statusCode: 500,
+    error: 'Internal Server Error',
+    message: 'test onError hook'
+  })
+
+  assert.equal(txPassed, true, 'transactionFinished assertions passed')
+})
diff --git a/test/versioned/fastify/code-level-metrics-hooks.tap.js b/test/versioned/fastify/code-level-metrics-hooks.tap.js
deleted file mode 100644
index c86d9b451d..0000000000
--- a/test/versioned/fastify/code-level-metrics-hooks.tap.js
+++ /dev/null
@@ -1,83 +0,0 @@
-/*
- * Copyright 2022 New Relic Corporation. All rights reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-'use strict'
-
-const tap = require('tap')
-const helper = require('../../lib/agent_helper')
-const common = require('./common')
-
-function setupFastifyServer(fastify) {
-  common.setupRoutes(fastify)
-}
-
-function setup(test, config) {
-  const agent = helper.instrumentMockedAgent(config)
-  const fastify = require('fastify')()
-
-  setupFastifyServer(fastify)
-
-  test.context.agent = agent
-  test.context.fastify = fastify
-
-  test.teardown(() => {
-    helper.unloadAgent(agent)
-    fastify.close()
-  })
-}
-
-tap.test('Fastify CLM Hook Based', (test) => {
-  test.autoend()
-  ;[true, false].forEach((isCLMEnabled) => {
-    test.test(isCLMEnabled ? 'should add attributes' : 'should not add attributes', async (t) => {
-      setup(t, { code_level_metrics: { enabled: isCLMEnabled } })
-      const { agent, fastify } = t.context
-
-      fastify.addHook('onRequest', function testOnRequest(...args) {
-        const next = args.pop()
-        next()
-      })
-
-      fastify.addHook('onSend', function testOnSend(...args) {
-        const next = args.pop()
-        next()
-      })
-
-      agent.on('transactionFinished', (transaction) => {
-        const baseSegment = transaction.trace.root.children
-        const [onRequestSegment, handlerSegment] = helper.isSecurityAgentEnabled(agent)
-          ? baseSegment[0].children[0].children
-          : baseSegment[0].children
-        const onSendSegment = handlerSegment.children[0]
-        t.clmAttrs({
-          segments: [
-            {
-              segment: onRequestSegment,
-              name: 'testOnRequest',
-              filepath: 'test/versioned/fastify/code-level-metrics-hooks.tap.js'
-            },
-            {
-              segment: onSendSegment,
-              name: 'testOnSend',
-              filepath: 'test/versioned/fastify/code-level-metrics-hooks.tap.js'
-            },
-            {
-              segment: handlerSegment,
-              name: 'routeHandler',
-              filepath: 'test/versioned/fastify/common.js'
-            }
-          ],
-          enabled: isCLMEnabled
-        })
-      })
-
-      await fastify.listen({ port: 0 })
-      const address = fastify.server.address()
-      const result = await common.makeRequest(address, '/add-hook')
-
-      t.same(result, { hello: 'world' })
-    })
-  })
-})
diff --git a/test/versioned/fastify/code-level-metrics-hooks.test.js b/test/versioned/fastify/code-level-metrics-hooks.test.js
new file mode 100644
index 0000000000..2ed4825e30
--- /dev/null
+++ b/test/versioned/fastify/code-level-metrics-hooks.test.js
@@ -0,0 +1,96 @@
+/*
+ * Copyright 2024 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+const test = require('node:test')
+const assert = require('node:assert')
+
+const { removeModules } = require('../../lib/cache-buster')
+const { assertCLMAttrs, match } = require('../../lib/custom-assertions')
+const helper = require('../../lib/agent_helper')
+const common = require('./common')
+
+test.beforeEach((ctx) => {
+  ctx.nr = { agent: null, fastify: null }
+})
+
+test.afterEach((ctx) => {
+  if (ctx.nr.agent) {
+    helper.unloadAgent(ctx.nr.agent)
+  }
+
+  if (ctx.nr.fastify) {
+    ctx.nr.fastify.close()
+  }
+
+  removeModules(['fastify'])
+})
+
+async function performTest(t) {
+  const { agent, fastify } = t.nr
+  fastify.addHook('onRequest', function testOnRequest(...args) {
+    const next = args.pop()
+    next()
+  })
+
+  fastify.addHook('onSend', function testOnSend(...args) {
+    const next = args.pop()
+    next()
+  })
+
+  let txPassed = false
+  agent.on('transactionFinished', (transaction) => {
+    const baseSegment = transaction.trace.root.children
+    const [onRequestSegment, handlerSegment] = helper.isSecurityAgentEnabled(agent)
+      ? baseSegment[0].children[0].children
+      : baseSegment[0].children
+    const onSendSegment = handlerSegment.children[0]
+    assertCLMAttrs({
+      segments: [
+        {
+          segment: onRequestSegment,
+          name: 'testOnRequest',
+          filepath: 'test/versioned/fastify/code-level-metrics-hooks.test.js'
+        },
+        {
+          segment: onSendSegment,
+          name: 'testOnSend',
+          filepath: 'test/versioned/fastify/code-level-metrics-hooks.test.js'
+        },
+        {
+          segment: handlerSegment,
+          name: 'routeHandler',
+          filepath: 'test/versioned/fastify/common.js'
+        }
+      ],
+      enabled: agent.config.code_level_metrics.enabled
+    })
+
+    txPassed = true
+  })
+
+  await fastify.listen({ port: 0 })
+  const address = fastify.server.address()
+  const result = await common.makeRequest(address, '/add-hook')
+
+  match(result, { hello: 'world' })
+
+  assert.equal(txPassed, true, 'transactionFinished assertions passed')
+}
+
+test('should add attributes', async (t) => {
+  t.nr.agent = helper.instrumentMockedAgent({ code_level_metrics: { enabled: true } })
+  t.nr.fastify = require('fastify')()
+  common.setupRoutes(t.nr.fastify)
+  await performTest(t)
+})
+
+test('should not add attributes', async (t) => {
+  t.nr.agent = helper.instrumentMockedAgent({ code_level_metrics: { enabled: false } })
+  t.nr.fastify = require('fastify')()
+  common.setupRoutes(t.nr.fastify)
+  await performTest(t)
+})
diff --git a/test/versioned/fastify/code-level-metrics-middleware.tap.js b/test/versioned/fastify/code-level-metrics-middleware.tap.js
deleted file mode 100644
index 0497a975b9..0000000000
--- a/test/versioned/fastify/code-level-metrics-middleware.tap.js
+++ /dev/null
@@ -1,115 +0,0 @@
-/*
- * Copyright 2022 New Relic Corporation. All rights reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-'use strict'
-
-const tap = require('tap')
-const helper = require('../../lib/agent_helper')
-const common = require('./common')
-const semver = require('semver')
-const { version: pkgVersion } = require('fastify/package')
-
-async function setupFastifyServer(fastify, calls) {
-  common.setupRoutes(fastify)
-  await fastify.register(require('middie'))
-  common.registerMiddlewares({ fastify, calls })
-}
-
-function setupFastifyServerV2(fastify, calls) {
-  common.setupRoutes(fastify)
-  common.registerMiddlewares({ fastify, calls })
-}
-
-async function setup(test, config) {
-  const agent = helper.instrumentMockedAgent(config)
-  const fastify = require('fastify')()
-  const calls = { test: 0, middleware: 0 }
-
-  // TODO: once we drop v2 support, update to use `setupFastifyServer` exclusively
-  const setupServerFn = semver.satisfies(pkgVersion, '>=3')
-    ? setupFastifyServer
-    : setupFastifyServerV2
-
-  await setupServerFn(fastify, calls)
-
-  test.context.agent = agent
-  test.context.fastify = fastify
-  test.context.calls = calls
-
-  test.teardown(() => {
-    helper.unloadAgent(agent)
-    fastify.close()
-  })
-}
-
-function assertSegments(test, baseSegment, isCLMEnabled) {
-  const { agent } = test.context
-  const { children } = helper.isSecurityAgentEnabled(agent) ? baseSegment.children[0] : baseSegment
-  // TODO: once we drop v2 support, this function can be removed and assert inline in test below
-  if (semver.satisfies(pkgVersion, '>=3')) {
-    const [middieSegment, handlerSegment] = children
-    test.clmAttrs({
-      segments: [
-        {
-          segment: middieSegment,
-          name: 'runMiddie',
-          filepath: 'test/versioned/fastify/node_modules/middie/index.js'
-        },
-        {
-          segment: handlerSegment,
-          name: '(anonymous)',
-          filepath: 'test/versioned/fastify/common.js'
-        }
-      ],
-      enabled: isCLMEnabled
-    })
-  } else {
-    const [middieSegment, mwSegment, handlerSegment] = children
-    test.clmAttrs({
-      segments: [
-        {
-          segment: middieSegment,
-          name: 'testMiddleware',
-          filepath: 'test/versioned/fastify/common.js'
-        },
-        {
-          segment: mwSegment,
-          name: 'pathMountedMiddleware',
-          filepath: 'test/versioned/fastify/common.js'
-        },
-        {
-          segment: handlerSegment,
-          name: '(anonymous)',
-          filepath: 'test/versioned/fastify/common.js'
-        }
-      ],
-      enabled: isCLMEnabled
-    })
-  }
-}
-
-tap.test('Fastify CLM Middleware Based', (test) => {
-  test.autoend()
-  ;[true, false].forEach((isCLMEnabled) => {
-    test.test(isCLMEnabled ? 'should add attributes' : 'should not add attributes', async (t) => {
-      await setup(t, { code_level_metrics: { enabled: isCLMEnabled } })
-      const { agent, fastify, calls } = t.context
-      const uri = common.routesToTest[0]
-
-      agent.on('transactionFinished', (transaction) => {
-        calls.test++
-        assertSegments(t, transaction.trace.root.children[0], isCLMEnabled)
-      })
-
-      await fastify.listen({ port: 0 })
-      const address = fastify.server.address()
-      const result = await common.makeRequest(address, uri)
-
-      t.equal(result.called, uri, `${uri} url did not error`)
-      t.ok(calls.test > 0)
-      t.equal(calls.test, calls.middleware, 'should be the same value')
-    })
-  })
-})
diff --git a/test/versioned/fastify/code-level-metrics-middleware.test.js b/test/versioned/fastify/code-level-metrics-middleware.test.js
new file mode 100644
index 0000000000..0449d88310
--- /dev/null
+++ b/test/versioned/fastify/code-level-metrics-middleware.test.js
@@ -0,0 +1,128 @@
+/*
+ * Copyright 2024 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+const test = require('node:test')
+const assert = require('node:assert')
+const semver = require('semver')
+
+const { version: pkgVersion } = require('fastify/package')
+
+const { removeModules } = require('../../lib/cache-buster')
+const { assertCLMAttrs } = require('../../lib/custom-assertions')
+const helper = require('../../lib/agent_helper')
+const common = require('./common')
+
+test.beforeEach((ctx) => {
+  ctx.nr = { agent: null, fastify: null, calls: { test: 0, middleware: 0 } }
+})
+
+test.afterEach((ctx) => {
+  if (ctx.nr.agent) {
+    helper.unloadAgent(ctx.nr.agent)
+  }
+
+  if (ctx.nr.fastify) {
+    ctx.nr.fastify.close()
+  }
+
+  removeModules(['fastify', '@fastify/middie', 'middie'])
+})
+
+async function setup(t, config) {
+  t.nr.agent = helper.instrumentMockedAgent(config)
+  t.nr.fastify = require('fastify')()
+
+  const { fastify, calls } = t.nr
+  if (semver.satisfies(pkgVersion, '>=3') === true) {
+    common.setupRoutes(fastify)
+
+    if (semver.major(pkgVersion) < 4) {
+      await fastify.register(require('middie'))
+    } else {
+      await fastify.register(require('@fastify/middie'))
+    }
+    common.registerMiddlewares({ fastify, calls })
+  } else {
+    // TODO: once we drop v2 support remove this case
+    common.setupRoutes(fastify)
+    common.registerMiddlewares({ fastify, calls })
+  }
+}
+
+function assertSegments(testContext, baseSegment, isCLMEnabled) {
+  const { agent } = testContext.nr
+  const { children } = helper.isSecurityAgentEnabled(agent) ? baseSegment.children[0] : baseSegment
+  // TODO: once we drop v2 support, this function can be removed and assert inline in test below
+  if (semver.satisfies(pkgVersion, '>=3')) {
+    const [middieSegment, handlerSegment] = children
+    assertCLMAttrs({
+      segments: [
+        {
+          segment: middieSegment,
+          name: 'runMiddie',
+          filepath: /test\/versioned\/fastify\/node_modules\/(@fastify)?\/middie\/index.js/
+        },
+        {
+          segment: handlerSegment,
+          name: '(anonymous)',
+          filepath: 'test/versioned/fastify/common.js'
+        }
+      ],
+      enabled: isCLMEnabled
+    })
+  } else {
+    const [middieSegment, mwSegment, handlerSegment] = children
+    assertCLMAttrs({
+      segments: [
+        {
+          segment: middieSegment,
+          name: 'testMiddleware',
+          filepath: 'test/versioned/fastify/common.js'
+        },
+        {
+          segment: mwSegment,
+          name: 'pathMountedMiddleware',
+          filepath: 'test/versioned/fastify/common.js'
+        },
+        {
+          segment: handlerSegment,
+          name: '(anonymous)',
+          filepath: 'test/versioned/fastify/common.js'
+        }
+      ],
+      enabled: isCLMEnabled
+    })
+  }
+}
+
+async function performTest(t) {
+  const { agent, fastify, calls } = t.nr
+  const uri = common.routesToTest[0]
+
+  agent.on('transactionFinished', (transaction) => {
+    calls.test++
+    assertSegments(t, transaction.trace.root.children[0], agent.config.code_level_metrics.enabled)
+  })
+
+  await fastify.listen({ port: 0 })
+  const address = fastify.server.address()
+  const result = await common.makeRequest(address, uri)
+
+  assert.equal(result.called, uri, `${uri} url did not error`)
+  assert.ok(calls.test > 0)
+  assert.equal(calls.test, calls.middleware, 'should be the same value')
+}
+
+test('should add attributes', async (t) => {
+  await setup(t, { code_level_metrics: { enabled: true } })
+  await performTest(t)
+})
+
+test('should not add attributes', async (t) => {
+  await setup(t, { code_level_metrics: { enabled: false } })
+  await performTest(t)
+})
diff --git a/test/versioned/fastify/common.js b/test/versioned/fastify/common.js
index 864954915f..438f3844c3 100644
--- a/test/versioned/fastify/common.js
+++ b/test/versioned/fastify/common.js
@@ -84,7 +84,7 @@ common.setupRoutes = (fastify) => {
 
 /**
  * Defines both a global middleware and middleware mounted at a specific
- * path. This tests the `middie`, and/or `fastify-express` plugin middlewawre
+ * path. This tests the `middie` and/or `fastify-express` plugin middleware
  * instrumentation
  */
 common.registerMiddlewares = ({ fastify, calls }) => {
diff --git a/test/versioned/fastify/errors.tap.js b/test/versioned/fastify/errors.test.js
similarity index 65%
rename from test/versioned/fastify/errors.tap.js
rename to test/versioned/fastify/errors.test.js
index 587e0550aa..71d50c05f8 100644
--- a/test/versioned/fastify/errors.tap.js
+++ b/test/versioned/fastify/errors.test.js
@@ -1,27 +1,33 @@
 /*
- * Copyright 2021 New Relic Corporation. All rights reserved.
+ * Copyright 2024 New Relic Corporation. All rights reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
 
 'use strict'
 
-const tap = require('tap')
-const helper = require('../../lib/agent_helper')
+const test = require('node:test')
+const assert = require('node:assert')
 const semver = require('semver')
+
+const helper = require('../../lib/agent_helper')
 const { makeRequest } = require('./common')
 
-tap.test('Test Errors', async (test) => {
+test('Test Errors', async (t) => {
   const agent = helper.instrumentMockedAgent()
   const fastify = require('fastify')()
   const { version: pkgVersion } = require('fastify/package')
 
-  test.teardown(() => {
+  t.after(() => {
     helper.unloadAgent(agent)
     fastify.close()
   })
 
   if (semver.satisfies(pkgVersion, '>=3')) {
-    await fastify.register(require('middie'))
+    if (semver.major(pkgVersion) < 4) {
+      await fastify.register(require('middie'))
+    } else {
+      await fastify.register(require('@fastify/middie'))
+    }
   }
 
   fastify.use((req, res, next) => {
@@ -34,6 +40,5 @@ tap.test('Test Errors', async (test) => {
   await fastify.listen({ port: 0 })
   const address = fastify.server.address()
   const res = await makeRequest(address, '/404-via-reply')
-  test.equal(res.statusCode, 404)
-  test.end()
+  assert.equal(res.statusCode, 404)
 })
diff --git a/test/versioned/fastify/fastify-2-naming.tap.js b/test/versioned/fastify/fastify-2-naming.tap.js
deleted file mode 100644
index b0f685edca..0000000000
--- a/test/versioned/fastify/fastify-2-naming.tap.js
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * Copyright 2021 New Relic Corporation. All rights reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-'use strict'
-
-const tap = require('tap')
-const helper = require('../../lib/agent_helper')
-const common = require('./common')
-const createTests = require('./naming-common')
-
-/**
- * Helper to return the list of expected segments
- *
- * @param {Array} uri
- * @returns {Array} formatted list of expected segments
- */
-function getExpectedSegments(uri) {
-  return [
-    'Nodejs/Middleware/Fastify/onRequest/testMiddleware',
-    `Nodejs/Middleware/Fastify/onRequest/pathMountedMiddleware/${uri}`,
-    `Nodejs/Middleware/Fastify/<anonymous>/${uri}`
-  ]
-}
-
-tap.test('Test Transaction Naming', (test) => {
-  test.autoend()
-
-  test.beforeEach(() => {
-    const agent = helper.instrumentMockedAgent()
-    const fastify = require('fastify')()
-    const calls = { test: 0, middleware: 0 }
-    test.context.agent = agent
-    test.context.fastify = fastify
-    test.context.calls = calls
-    common.setupRoutes(fastify)
-    common.registerMiddlewares({ fastify, calls })
-  })
-
-  test.afterEach(() => {
-    const { fastify, agent } = test.context
-    helper.unloadAgent(agent)
-    fastify.close()
-  })
-
-  createTests(test, getExpectedSegments)
-})
diff --git a/test/versioned/fastify/fastify-2-naming.test.js b/test/versioned/fastify/fastify-2-naming.test.js
new file mode 100644
index 0000000000..a20046c50f
--- /dev/null
+++ b/test/versioned/fastify/fastify-2-naming.test.js
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2024 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+const test = require('node:test')
+
+const { removeModules } = require('../../lib/cache-buster')
+const helper = require('../../lib/agent_helper')
+const common = require('./common')
+const runTests = require('./naming-common')
+
+/**
+ * Helper to return the list of expected segments
+ *
+ * @param {Array} uri
+ * @returns {Array} formatted list of expected segments
+ */
+function getExpectedSegments(uri) {
+  return [
+    'Nodejs/Middleware/Fastify/onRequest/testMiddleware',
+    `Nodejs/Middleware/Fastify/onRequest/pathMountedMiddleware/${uri}`,
+    `Nodejs/Middleware/Fastify/<anonymous>/${uri}`
+  ]
+}
+
+test.beforeEach((ctx) => {
+  ctx.nr = {}
+  ctx.nr.agent = helper.instrumentMockedAgent()
+
+  const calls = { test: 0, middleware: 0 }
+  const fastify = require('fastify')()
+  common.setupRoutes(fastify)
+  common.registerMiddlewares({ fastify, calls })
+  ctx.nr.calls = calls
+  ctx.nr.fastify = fastify
+})
+
+test.afterEach((ctx) => {
+  helper.unloadAgent(ctx.nr.agent)
+  ctx.nr.fastify.close()
+
+  removeModules(['fastify'])
+})
+
+test('fastify@2 transaction naming', async (t) => {
+  await runTests(t, getExpectedSegments)
+})
diff --git a/test/versioned/fastify/fastify-3-naming.tap.js b/test/versioned/fastify/fastify-3-naming.tap.js
deleted file mode 100644
index ac15ed2331..0000000000
--- a/test/versioned/fastify/fastify-3-naming.tap.js
+++ /dev/null
@@ -1,114 +0,0 @@
-/*
- * Copyright 2021 New Relic Corporation. All rights reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-'use strict'
-
-const tap = require('tap')
-const helper = require('../../lib/agent_helper')
-const common = require('./common')
-const createTests = require('./naming-common')
-
-async function setupFastifyServer(fastify, calls) {
-  common.setupRoutes(fastify)
-  await fastify.register(require('middie'))
-  common.registerMiddlewares({ fastify, calls })
-}
-
-/**
- * Helper to return the list of expected segments
- *
- * @param {Array} uri
- * @returns {Array} formatted list of expected segments
- */
-function getExpectedSegments(uri) {
-  return [
-    'Nodejs/Middleware/Fastify/onRequest/runMiddie',
-    [
-      'Nodejs/Middleware/Fastify/onRequest/testMiddleware',
-      `Nodejs/Middleware/Fastify/onRequest/pathMountedMiddleware/${uri}`
-    ],
-    `Nodejs/Middleware/Fastify/<anonymous>/${uri}`
-  ]
-}
-
-tap.test('Test Transaction Naming - Standard Export', (test) => {
-  test.autoend()
-
-  test.beforeEach(async (t) => {
-    const agent = helper.instrumentMockedAgent()
-    const fastify = require('fastify')()
-    const calls = { test: 0, middleware: 0 }
-    await setupFastifyServer(fastify, calls)
-
-    t.context.agent = agent
-    t.context.fastify = fastify
-    t.context.calls = calls
-  })
-
-  test.afterEach((t) => {
-    const { agent, fastify } = t.context
-
-    helper.unloadAgent(agent)
-    fastify.close()
-  })
-
-  createTests(test, getExpectedSegments)
-})
-
-tap.test('Test Transaction Naming - Fastify Property', (test) => {
-  test.autoend()
-
-  test.beforeEach(async (t) => {
-    const agent = helper.instrumentMockedAgent({
-      feature_flag: {
-        fastify_instrumentation: true
-      }
-    })
-    const fastify = require('fastify').fastify()
-    const calls = { test: 0, middleware: 0 }
-    await setupFastifyServer(fastify, calls)
-
-    t.context.agent = agent
-    t.context.fastify = fastify
-    t.context.calls = calls
-  })
-
-  test.afterEach((t) => {
-    const { agent, fastify } = t.context
-
-    helper.unloadAgent(agent)
-    fastify.close()
-  })
-
-  createTests(test, getExpectedSegments)
-})
-
-tap.test('Test Transaction Naming - Default Property', (test) => {
-  test.autoend()
-
-  test.beforeEach(async (t) => {
-    const agent = helper.instrumentMockedAgent({
-      feature_flag: {
-        fastify_instrumentation: true
-      }
-    })
-    const fastify = require('fastify').default()
-    const calls = { test: 0, middleware: 0 }
-    await setupFastifyServer(fastify, calls)
-
-    t.context.agent = agent
-    t.context.fastify = fastify
-    t.context.calls = calls
-  })
-
-  test.afterEach((t) => {
-    const { agent, fastify } = t.context
-
-    helper.unloadAgent(agent)
-    fastify.close()
-  })
-
-  createTests(test, getExpectedSegments)
-})
diff --git a/test/versioned/fastify/fastify-3.tap.js b/test/versioned/fastify/fastify-3.tap.js
deleted file mode 100644
index 0adf7d50f9..0000000000
--- a/test/versioned/fastify/fastify-3.tap.js
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2021 New Relic Corporation. All rights reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-'use strict'
-
-const tap = require('tap')
-
-const helper = require('../../lib/agent_helper')
-const symbols = require('../../../lib/symbols')
-
-tap.test('Fastify Instrumentation', (t) => {
-  t.autoend()
-
-  let agent = null
-  let fastifyExport = null
-
-  t.beforeEach(() => {
-    agent = helper.instrumentMockedAgent({
-      feature_flag: {
-        fastify_instrumentation: true
-      }
-    })
-    fastifyExport = require('fastify')
-  })
-
-  t.afterEach(() => {
-    helper.unloadAgent(agent)
-  })
-
-  /**
-   * Fastify v3 has '.fastify' and '.default' properties attached to the exported
-   * 'fastify' function. These are all the same original exported function, just
-   * arranged to support a variety of import styles.
-   */
-  t.test('Should propagate fastify exports when instrumented', (t) => {
-    const original = fastifyExport[symbols.original]
-
-    // Confirms the original setup matches expectations
-    t.equal(original.fastify, original)
-    t.equal(original.default, original)
-
-    // Asserts our new export has the same behavior
-    t.equal(fastifyExport.fastify, fastifyExport)
-    t.equal(fastifyExport.default, fastifyExport)
-
-    t.end()
-  })
-})
diff --git a/test/versioned/fastify/fastify-gte3-naming.test.js b/test/versioned/fastify/fastify-gte3-naming.test.js
new file mode 100644
index 0000000000..9680230029
--- /dev/null
+++ b/test/versioned/fastify/fastify-gte3-naming.test.js
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2024 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+const test = require('node:test')
+const semver = require('semver')
+
+const { version: pkgVersion } = require('fastify/package')
+
+const { removeModules } = require('../../lib/cache-buster')
+const helper = require('../../lib/agent_helper')
+const common = require('./common')
+const runTests = require('./naming-common')
+
+/**
+ * Helper to return the list of expected segments
+ *
+ * @param {Array} uri
+ * @returns {Array} formatted list of expected segments
+ */
+function getExpectedSegments(uri) {
+  return [
+    'Nodejs/Middleware/Fastify/onRequest/runMiddie',
+    [
+      'Nodejs/Middleware/Fastify/onRequest/testMiddleware',
+      `Nodejs/Middleware/Fastify/onRequest/pathMountedMiddleware/${uri}`
+    ],
+    `Nodejs/Middleware/Fastify/<anonymous>/${uri}`
+  ]
+}
+
+async function setupFastifyServer(fastify, calls) {
+  common.setupRoutes(fastify)
+
+  if (semver.major(pkgVersion) === 3) {
+    await fastify.register(require('middie'))
+  } else {
+    await fastify.register(require('@fastify/middie'))
+  }
+
+  common.registerMiddlewares({ fastify, calls })
+}
+
+test('standard export', async (t) => {
+  test.beforeEach(async (ctx) => {
+    ctx.nr = {}
+    ctx.nr.agent = helper.instrumentMockedAgent()
+
+    const calls = { test: 0, middleware: 0 }
+    const fastify = require('fastify')()
+    await setupFastifyServer(fastify, calls)
+    ctx.nr.calls = calls
+    ctx.nr.fastify = fastify
+  })
+
+  test.afterEach((ctx) => {
+    helper.unloadAgent(ctx.nr.agent)
+    ctx.nr.fastify.close()
+
+    removeModules(['fastify', '@fastify/middie', 'middie'])
+  })
+
+  await t.test(async (t) => {
+    await runTests(t, getExpectedSegments)
+  })
+})
+
+test('fastify property', async (t) => {
+  test.beforeEach(async (ctx) => {
+    ctx.nr = {}
+    ctx.nr.agent = helper.instrumentMockedAgent()
+
+    const calls = { test: 0, middleware: 0 }
+    const fastify = require('fastify').fastify()
+    await setupFastifyServer(fastify, calls)
+    ctx.nr.calls = calls
+    ctx.nr.fastify = fastify
+  })
+
+  test.afterEach((ctx) => {
+    helper.unloadAgent(ctx.nr.agent)
+    ctx.nr.fastify.close()
+
+    removeModules(['fastify', '@fastify/middie', 'middie'])
+  })
+
+  await t.test(async (t) => {
+    await runTests(t, getExpectedSegments)
+  })
+})
+
+test('default property', async (t) => {
+  test.beforeEach(async (ctx) => {
+    ctx.nr = {}
+    ctx.nr.agent = helper.instrumentMockedAgent()
+
+    const calls = { test: 0, middleware: 0 }
+    const fastify = require('fastify').default()
+    await setupFastifyServer(fastify, calls)
+    ctx.nr.calls = calls
+    ctx.nr.fastify = fastify
+  })
+
+  test.afterEach((ctx) => {
+    helper.unloadAgent(ctx.nr.agent)
+    ctx.nr.fastify.close()
+
+    removeModules(['fastify', '@fastify/middie', 'middie'])
+  })
+
+  await t.test(async (t) => {
+    await runTests(t, getExpectedSegments)
+  })
+})
diff --git a/test/versioned/fastify/fastify-gte3.test.js b/test/versioned/fastify/fastify-gte3.test.js
new file mode 100644
index 0000000000..ddaf287c4e
--- /dev/null
+++ b/test/versioned/fastify/fastify-gte3.test.js
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2024 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+const test = require('node:test')
+const assert = require('node:assert')
+
+const helper = require('../../lib/agent_helper')
+const symbols = require('../../../lib/symbols')
+
+/**
+ * Fastify v3 has '.fastify' and '.default' properties attached to the exported
+ * 'fastify' function. These are all the same original exported function, just
+ * arranged to support a variety of import styles.
+ */
+test('Should propagate fastify exports when instrumented', () => {
+  helper.instrumentMockedAgent()
+  const Fastify = require('fastify')
+  const original = Fastify[symbols.original]
+
+  // Confirms the original setup matches expectations
+  assert.equal(original.fastify, original)
+  assert.equal(original.default, original)
+
+  // Asserts our new export has the same behavior
+  assert.equal(Fastify.fastify, Fastify)
+  assert.equal(Fastify.default, Fastify)
+})
diff --git a/test/versioned/fastify/naming-common.js b/test/versioned/fastify/naming-common.js
index 4b692c2a6c..af4522008e 100644
--- a/test/versioned/fastify/naming-common.js
+++ b/test/versioned/fastify/naming-common.js
@@ -4,18 +4,25 @@
  */
 
 'use strict'
+
+const assert = require('node:assert')
+
 const { routesToTest, makeRequest } = require('./common')
-require('../../lib/metrics_helper')
+const { assertSegments, match } = require('../../lib/custom-assertions')
 const helper = require('../../lib/agent_helper')
 
-module.exports = function createTests(t, getExpectedSegments) {
-  routesToTest.forEach((uri) => {
-    t.test(`testing naming for ${uri} `, async (t) => {
-      const { agent, fastify, calls } = t.context
+module.exports = async function runTests(t, getExpectedSegments) {
+  // Since we have spawned these sub-tests from another sub-test we must
+  // clear out the agent before they are evaluated.
+  helper.unloadAgent(t.nr.agent)
+
+  for (const uri of routesToTest) {
+    await t.test(`testing naming for ${uri} `, async (t) => {
+      const { agent, fastify, calls } = t.nr
 
       agent.on('transactionFinished', (transaction) => {
         calls.test++
-        t.equal(
+        assert.equal(
           `WebFrameworkUri/Fastify/GET/${uri}`,
           transaction.getName(),
           `transaction name matched for ${uri}`
@@ -36,33 +43,37 @@ module.exports = function createTests(t, getExpectedSegments) {
           ]
         }
 
-        t.assertSegments(transaction.trace.root, expectedSegments)
+        assertSegments(transaction.trace.root, expectedSegments)
       })
 
       await fastify.listen({ port: 0 })
       const address = fastify.server.address()
       const result = await makeRequest(address, uri)
-      t.equal(result.called, uri, `${uri} url did not error`)
-      t.ok(calls.test > 0)
-      t.equal(calls.test, calls.middleware, 'should be the same value')
-      t.end()
+      assert.equal(result.called, uri, `${uri} url did not error`)
+      assert.ok(calls.test > 0)
+      assert.equal(calls.test, calls.middleware, 'should be the same value')
     })
-  })
+  }
 
-  t.test('should properly name transaction with parameterized routes', async (t) => {
-    const { fastify, agent } = t.context
+  await t.test('should properly name transaction with parameterized routes', async (t) => {
+    const { fastify, agent } = t.nr
 
+    let txPassed = false
     agent.on('transactionFinished', (transaction) => {
-      t.equal(
+      assert.equal(
         transaction.name,
         'WebTransaction/WebFrameworkUri/Fastify/GET//params/:id/:parent/edit'
       )
-      t.equal(transaction.url, '/params/id/parent/edit')
+      assert.equal(transaction.url, '/params/id/parent/edit')
+
+      txPassed = true
     })
+
     await fastify.listen()
     const address = fastify.server.address()
     const result = await makeRequest(address, '/params/id/parent/edit')
-    t.same(result, { id: 'id', parent: 'parent' })
-    t.end()
+    match(result, { id: 'id', parent: 'parent' })
+
+    assert.equal(txPassed, true, 'transactionFinished assertions passed')
   })
 }
diff --git a/test/versioned/fastify/new-state-tracking.tap.js b/test/versioned/fastify/new-state-tracking.tap.js
deleted file mode 100644
index d9eb76d856..0000000000
--- a/test/versioned/fastify/new-state-tracking.tap.js
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * Copyright 2021 New Relic Corporation. All rights reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-'use strict'
-
-const tap = require('tap')
-const helper = require('../../lib/agent_helper')
-const common = require('./common')
-
-const originalSetImmediate = setImmediate
-
-tap.test('fastify with new state tracking', (t) => {
-  t.autoend()
-
-  let agent = null
-  let fastify = null
-
-  t.beforeEach(() => {
-    agent = helper.instrumentMockedAgent({
-      feature_flag: {
-        new_promise_tracking: true
-      }
-    })
-
-    fastify = require('fastify')()
-  })
-
-  t.afterEach(() => {
-    helper.unloadAgent(agent)
-    fastify.close()
-  })
-
-  t.test('should not reuse transactions via normal usage', async (t) => {
-    fastify.get('/', async () => {
-      return { hello: 'world' }
-    })
-
-    await fastify.listen({ port: 0 })
-
-    const address = fastify.server.address()
-
-    const transactions = []
-    agent.on('transactionFinished', (transaction) => {
-      transactions.push(transaction)
-    })
-
-    await common.makeRequest(address, '/')
-    await common.makeRequest(address, '/')
-
-    t.equal(transactions.length, 2)
-  })
-
-  t.test('should not reuse transactions with non-awaited promise', async (t) => {
-    fastify.get('/', async () => {
-      doWork() // fire-and-forget promise
-      return { hello: 'world' }
-    })
-
-    function doWork() {
-      return new Promise((resolve) => {
-        // async hop w/o context tracking
-        originalSetImmediate(resolve)
-      })
-    }
-
-    await fastify.listen({ port: 0 })
-
-    const address = fastify.server.address()
-
-    const transactions = []
-    agent.on('transactionFinished', (transaction) => {
-      transactions.push(transaction)
-    })
-
-    await common.makeRequest(address, '/')
-    await common.makeRequest(address, '/')
-
-    t.equal(transactions.length, 2)
-  })
-})
diff --git a/test/versioned/fastify/new-state-tracking.test.js b/test/versioned/fastify/new-state-tracking.test.js
new file mode 100644
index 0000000000..146bb21f6d
--- /dev/null
+++ b/test/versioned/fastify/new-state-tracking.test.js
@@ -0,0 +1,77 @@
+/*
+ * Copyright 2024 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+const test = require('node:test')
+const assert = require('node:assert')
+
+const helper = require('../../lib/agent_helper')
+const common = require('./common')
+
+test.beforeEach((ctx) => {
+  ctx.nr = {}
+  ctx.nr.agent = helper.instrumentMockedAgent({ feature_flag: { new_promise_tracking: true } })
+  ctx.nr.fastify = require('fastify')()
+  ctx.nr.originalSetImmediate = global.setImmediate
+})
+
+test.afterEach((ctx) => {
+  helper.unloadAgent(ctx.nr.agent)
+  ctx.nr.fastify.close()
+  global.setImmediate = ctx.nr.originalSetImmediate
+})
+
+test('should not reuse transactions via normal usage', async (t) => {
+  const { agent, fastify } = t.nr
+
+  fastify.get('/', async () => {
+    return { hello: 'world' }
+  })
+
+  await fastify.listen({ port: 0 })
+
+  const address = fastify.server.address()
+
+  const transactions = []
+  agent.on('transactionFinished', (transaction) => {
+    transactions.push(transaction)
+  })
+
+  await common.makeRequest(address, '/')
+  await common.makeRequest(address, '/')
+
+  assert.equal(transactions.length, 2)
+})
+
+test('should not reuse transactions with non-awaited promise', async (t) => {
+  const { agent, fastify, originalSetImmediate } = t.nr
+
+  fastify.get('/', async () => {
+    doWork() // fire-and-forget promise
+    return { hello: 'world' }
+  })
+
+  function doWork() {
+    return new Promise((resolve) => {
+      // async hop w/o context tracking
+      originalSetImmediate(resolve)
+    })
+  }
+
+  await fastify.listen({ port: 0 })
+
+  const address = fastify.server.address()
+
+  const transactions = []
+  agent.on('transactionFinished', (transaction) => {
+    transactions.push(transaction)
+  })
+
+  await common.makeRequest(address, '/')
+  await common.makeRequest(address, '/')
+
+  assert.equal(transactions.length, 2)
+})
diff --git a/test/versioned/fastify/package.json b/test/versioned/fastify/package.json
index a088c18f66..2bfbecd34c 100644
--- a/test/versioned/fastify/package.json
+++ b/test/versioned/fastify/package.json
@@ -1,6 +1,11 @@
 {
   "name": "fastify-tests",
-  "targets": [{"name":"fastify","minAgentVersion":"8.5.0"}],
+  "targets": [
+    {
+      "name": "fastify",
+      "minAgentVersion": "8.5.0"
+    }
+  ],
   "version": "0.0.0",
   "private": true,
   "tests": [
@@ -12,34 +17,65 @@
         "fastify": ">=2.0.0 < 3"
       },
       "files": [
-        "add-hook.tap.js",
-        "code-level-metrics-middleware.tap.js",
-        "code-level-metrics-hooks.tap.js",
-        "errors.tap.js",
-        "fastify-2-naming.tap.js",
-        "new-state-tracking.tap.js"
+        "add-hook.test.js",
+        "code-level-metrics-middleware.test.js",
+        "code-level-metrics-hooks.test.js",
+        "errors.test.js",
+        "fastify-2-naming.test.js",
+        "new-state-tracking.test.js"
+      ]
+    },
+
+    {
+      "engines": {
+        "node": ">=18"
+      },
+      "dependencies": {
+        "fastify": "^3.0.0",
+        "middie": ">=3.0.0 && <7.0.0"
+      },
+      "files": [
+        "fastify-gte3.test.js",
+        "fastify-gte3-naming.test.js"
       ]
     },
+
     {
       "engines": {
         "node": ">=18"
       },
       "dependencies": {
-        "fastify": ">=3.0.0",
-        "middie": "5.3.0"
+        "fastify": "^4.0.0",
+        "@fastify/middie": ">=7.0.0 && <9.0.0"
       },
       "files": [
-        "add-hook.tap.js",
-        "code-level-metrics-middleware.tap.js",
-        "code-level-metrics-hooks.tap.js",
-        "errors.tap.js",
-        "fastify-3.tap.js",
-        "fastify-3-naming.tap.js",
-        "new-state-tracking.tap.js"
+        "fastify-gte3.test.js",
+        "fastify-gte3-naming.test.js",
+        "add-hook.test.js",
+        "code-level-metrics-middleware.test.js",
+        "code-level-metrics-hooks.test.js",
+        "errors.test.js",
+        "new-state-tracking.test.js"
+      ]
+    },
+
+    {
+      "engines": {
+        "node": ">=18"
+      },
+      "dependencies": {
+        "fastify": "^5.0.0",
+        "@fastify/middie": ">=9.0.0"
+      },
+      "files": [
+        "fastify-gte3.test.js",
+        "fastify-gte3-naming.test.js",
+        "add-hook.test.js",
+        "code-level-metrics-middleware.test.js",
+        "code-level-metrics-hooks.test.js",
+        "errors.test.js",
+        "new-state-tracking.test.js"
       ]
     }
-  ],
-  "engines": {
-    "node": ">=18"
-  }
+  ]
 }