diff --git a/api.js b/api.js
index 8e9fa6fb9e..a7083863cb 100644
--- a/api.js
+++ b/api.js
@@ -1312,7 +1312,7 @@ API.prototype.recordCustomEvent = function recordCustomEvent(eventType, attribut
  *
  * @param {string|object} moduleName The module name given to require to load the module, or the instrumentation specification
  * @param {string} moduleName.moduleName The module name given to require to load the module
- * @param {Function}  moduleName.onResolved The function to call prior to module load after the filepath has been resolved
+ * @param {string} [moduleName.absolutePath] Must provide absolute path to module if it does not exist within node_modules. This is used to instrument a file within the same application.
  * @param {Function}  moduleName.onRequire The function to call when the module has been loaded
  * @param {Function} [moduleName.onError] If provided, should `onRequire` throw an error, the error will be passed to
  * @param {Function} onRequire The function to call when the module has been loaded
@@ -1343,7 +1343,7 @@ API.prototype.instrument = function instrument(moduleName, onRequire, onError) {
  *
  * @param {string|object} moduleName The module name given to require to load the module, or the instrumentation specification
  * @param {string} moduleName.moduleName The module name given to require to load the module
- * @param {Function}  moduleName.onResolved The function to call prior to module load after the filepath has been resolved
+ * @param {string} [moduleName.absolutePath] Must provide absolute path to module if it does not exist within node_modules. This is used to instrument a file within the same application.
  * @param {Function}  moduleName.onRequire The function to call when the module has been loaded
  * @param {Function} [moduleName.onError] If provided, should `onRequire` throw an error, the error will be passed to
  * @param {Function} onRequire The function to call when the module has been loaded
@@ -1375,7 +1375,7 @@ API.prototype.instrumentConglomerate = function instrumentConglomerate(
  *
  * @param {string|object} moduleName The module name given to require to load the module, or the instrumentation specification
  * @param {string} moduleName.moduleName The module name given to require to load the module
- * @param {Function}  moduleName.onResolved The function to call prior to module load after the filepath has been resolved
+ * @param {string} [moduleName.absolutePath] Must provide absolute path to module if it does not exist within node_modules. This is used to instrument a file within the same application.
  * @param {Function}  moduleName.onRequire The function to call when the module has been loaded
  * @param {Function} [moduleName.onError] If provided, should `onRequire` throw an error, the error will be passed to
  * @param {Function} onRequire The function to call when the module has been loaded
@@ -1408,7 +1408,7 @@ API.prototype.instrumentDatastore = function instrumentDatastore(moduleName, onR
  *
  * @param {string|object} moduleName The module name given to require to load the module, or the instrumentation specification
  * @param {string} moduleName.moduleName The module name given to require to load the module
- * @param {Function}  moduleName.onResolved The function to call prior to module load after the filepath has been resolved
+ * @param {string} [moduleName.absolutePath] Must provide absolute path to module if it does not exist within node_modules. This is used to instrument a file within the same application.
  * @param {Function}  moduleName.onRequire The function to call when the module has been loaded
  * @param {Function} [moduleName.onError] If provided, should `onRequire` throw an error, the error will be passed to
  * @param {Function} onRequire The function to call when the module has been loaded
@@ -1445,7 +1445,7 @@ API.prototype.instrumentWebframework = function instrumentWebframework(
  *
  * @param {string|object} moduleName The module name given to require to load the module, or the instrumentation specification
  * @param {string} moduleName.moduleName The module name given to require to load the module
- * @param {Function}  moduleName.onResolved The function to call prior to module load after the filepath has been resolved
+ * @param {string} [moduleName.absolutePath] Must provide absolute path to module if it does not exist within node_modules. This is used to instrument a file within the same application.
  * @param {Function}  moduleName.onRequire The function to call when the module has been loaded
  * @param {Function} [moduleName.onError] If provided, should `onRequire` throw an error, the error will be passed to
  * @param {Function} onRequire The function to call when the module has been loaded
diff --git a/lib/shimmer.js b/lib/shimmer.js
index 56eb9b6570..902831364f 100644
--- a/lib/shimmer.js
+++ b/lib/shimmer.js
@@ -398,11 +398,17 @@ const shimmer = (module.exports = {
 
     if (!registeredInstrumentation) {
       shimmer.registeredInstrumentations[opts.moduleName] = []
+      // In cases where a customer is trying to instrument a file
+      // that is not within node_modules, they must provide the absolutePath
+      // so require-in-the-middle can call our callback. the moduleName
+      // still needs to be the resolved name so we can look up our instrumentation correctly
+      const pkgHook = opts.absolutePath || opts.moduleName
+
       // not using a set because this is shared by reference
       // to allow custom instrumentation to be loaded after the
       // agent is bootstrapped
-      if (!pkgsToHook.includes(opts.moduleName)) {
-        pkgsToHook.push(opts.moduleName)
+      if (!pkgsToHook.includes(pkgHook)) {
+        pkgsToHook.push(pkgHook)
       }
     }
 
diff --git a/test/integration/module-loading/local-package.js b/test/integration/module-loading/local-package.js
new file mode 100644
index 0000000000..6cc0a75cc7
--- /dev/null
+++ b/test/integration/module-loading/local-package.js
@@ -0,0 +1,8 @@
+/*
+ * Copyright 2020 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+module.exports = () => ({ hello: 'world' })
diff --git a/test/integration/module-loading/module-loading.tap.js b/test/integration/module-loading/module-loading.tap.js
index c704f48ca4..a3ade92c1d 100644
--- a/test/integration/module-loading/module-loading.tap.js
+++ b/test/integration/module-loading/module-loading.tap.js
@@ -13,6 +13,8 @@ const shimmer = require('../../../lib/shimmer')
 const symbols = require('../../../lib/symbols')
 const { FEATURES } = require('../../../lib/metrics/names')
 
+const LOCAL_MODULE = 'local-package'
+const LOCAL_MODULE_PATH = require.resolve('./local-package')
 const CUSTOM_MODULE = 'customTestPackage'
 const CUSTOM_MODULE_PATH = `./node_modules/${CUSTOM_MODULE}`
 const CUSTOM_MODULE_PATH_SUB = `./node_modules/subPkg/node_modules/${CUSTOM_MODULE}`
@@ -177,6 +179,36 @@ tap.test('Should create usage version metric onRequire', (t) => {
   }
 })
 
+tap.test('should instrument a local package', (t) => {
+  let agent = helper.instrumentMockedAgent()
+
+  t.teardown(() => {
+    helper.unloadAgent(agent)
+    agent = null
+  })
+
+  shimmer.registerInstrumentation({
+    moduleName: LOCAL_MODULE,
+    absolutePath: LOCAL_MODULE_PATH,
+    onRequire: onRequireHandler
+  })
+
+  require('./local-package')
+
+  function onRequireHandler(shim, localPkg, name) {
+    t.equal(
+      shim.pkgVersion,
+      process.version,
+      'defaults to node version for pkgVersion as this is not a package'
+    )
+    t.ok(shim.id)
+    t.equal(name, LOCAL_MODULE)
+    const result = localPkg()
+    t.same(result, { hello: 'world' })
+    t.end()
+  }
+})
+
 function simulateTestLoadAndUnload() {
   const agent = helper.instrumentMockedAgent()
 
diff --git a/test/unit/api/api-instrument-messages.test.js b/test/unit/api/api-instrument-messages.test.js
new file mode 100644
index 0000000000..becc3ebeaa
--- /dev/null
+++ b/test/unit/api/api-instrument-messages.test.js
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2020 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+const tap = require('tap')
+const API = require('../../../api')
+const helper = require('../../lib/agent_helper')
+const sinon = require('sinon')
+const shimmer = require('../../../lib/shimmer')
+
+tap.test('Agent API - instrumentMessages', (t) => {
+  t.autoend()
+
+  let agent = null
+  let api = null
+
+  t.beforeEach(() => {
+    agent = helper.loadMockedAgent()
+    api = new API(agent)
+
+    sinon.spy(shimmer, 'registerInstrumentation')
+  })
+
+  t.afterEach(() => {
+    helper.unloadAgent(agent)
+    agent = null
+
+    shimmer.registerInstrumentation.restore()
+  })
+
+  t.test('should register the instrumentation with shimmer', (t) => {
+    const opts = {
+      moduleName: 'foobar',
+      absolutePath: `${__dirname}/foobar`,
+      onRequire: function () {}
+    }
+    api.instrumentMessages(opts)
+
+    t.ok(shimmer.registerInstrumentation.calledOnce)
+    const args = shimmer.registerInstrumentation.getCall(0).args
+    const [actualOpts] = args
+
+    t.same(actualOpts, opts)
+    t.equal(actualOpts.type, 'message')
+
+    t.end()
+  })
+
+  t.test('should convert separate args into an options object', (t) => {
+    function onRequire() {}
+    function onError() {}
+    api.instrumentMessages('foobar', onRequire, onError)
+
+    const opts = shimmer.registerInstrumentation.getCall(0).args[0]
+    t.equal(opts.moduleName, 'foobar')
+    t.equal(opts.onRequire, onRequire)
+    t.equal(opts.onError, onError)
+
+    t.end()
+  })
+})