diff --git a/README.md b/README.md
index 8d301c0..9b4c56d 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,6 @@ To load esm loader:
 ```js
 // esm-loader.mjs
 import { register } from 'node:module';
-const packages = new Set(['pkg1', 'pkg2']);
 const instrumentations = [
   {
     channelName: 'channel1',
@@ -31,7 +30,7 @@ const instrumentations = [
 ]
 
 register('@apm-js-collab/tracing-hooks/hook.mjs', import.meta.url, {
-  data: { instrumentations, packages }
+  data: { instrumentations }
 });
 ```
 
@@ -46,7 +45,6 @@ To load CJS patch:
 ```js
 // cjs-patch.js
 const ModulePatch = require('@apm-js-collab/tracing-hooks')
-const packages = new Set(['pkg1', 'pkg2']);
 const instrumentations = [
   {
     channelName: 'channel1',
@@ -61,7 +59,7 @@ const instrumentations = [
     channelName: 'channel2',
     module: { name: 'pkg2', verisonRange: '>=1.0.0', filePath: 'index.js' },
     functionQuery: {
-      className: 'Class2,
+      className: 'Class2',
       methodName: 'method2', 
       kind: 'Sync'
     }
@@ -69,7 +67,7 @@ const instrumentations = [
 ]
 
 
-const modulePatch = new ModulePatch({ instrumentations, packages });
+const modulePatch = new ModulePatch({ instrumentations });
 modulePatch.patch()
 ```
 
diff --git a/hook.mjs b/hook.mjs
index 6195207..d10fa63 100644
--- a/hook.mjs
+++ b/hook.mjs
@@ -13,7 +13,7 @@ let instrumentator = null
 export async function initialize(data = {}) {
   const instrumentations = data?.instrumentations || []
   instrumentator = create(instrumentations)
-  packages = data?.packages || new Set()
+  packages = new Set(instrumentations.map(i => i.module.name))
   transformers = new Map()
 }
 
diff --git a/index.js b/index.js
index 5c862a7..e3b4cd7 100644
--- a/index.js
+++ b/index.js
@@ -6,8 +6,8 @@ const getPackageVersion = require('./lib/get-package-version')
 const debug = require('debug')('@apm-js-collab/tracing-hooks:module-patch')
 
 class ModulePatch {
-  constructor({ packages = new Set(), instrumentations = [] } = {}) {
-    this.packages = packages
+  constructor({ instrumentations = [] } = {}) {
+    this.packages = new Set(instrumentations.map(i => i.module.name))
     this.instrumentator = create(instrumentations)
     this.transformers = new Map()
     this.resolve = Module._resolveFilename
diff --git a/test/hook.test.mjs b/test/hook.test.mjs
index 582bc77..c0a42fc 100644
--- a/test/hook.test.mjs
+++ b/test/hook.test.mjs
@@ -7,9 +7,7 @@ import Snap from '@matteo.collina/snap'
 
 test.beforeEach(async (t) => {
   const esmLoaderRewriter = await import('../hook.mjs')
-  const packages = new Set(['esm-pkg', 'pkg-1'])
   esmLoaderRewriter.initialize({
-    packages,
     instrumentations: [
         {
           channelName: 'unitTestEsm',
@@ -152,9 +150,7 @@ test('should not rewrite code if it does not match a subscriber and a cjs module
 
 test('should not rewrite code if a function query does not exist in file', async (t) => {
   const { esmLoaderRewriter, snap } = t.ctx
-  const packages = new Set(['esm-pkg'])
   esmLoaderRewriter.initialize({
-    packages,
     instrumentations: [
         {
           channelName: 'unitTestEsm',
diff --git a/test/index.test.js b/test/index.test.js
index b1466da..aeab88f 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -10,7 +10,6 @@ const { readFileSync } = require('node:fs')
 
 test.beforeEach((t) => {
   const subscribers = {
-    packages: new Set(['pkg-1']),
     instrumentations: [
       {
         channelName: 'unitTest',
@@ -92,7 +91,6 @@ test('should not rewrite code for an unmatch patch', async (t) => {
 test('should not rewrite code if a function query does not exist in file', async (t) => {
   const { modulePath, snap } = t.ctx
   const subscribers = {
-    packages: new Set(['pkg-1']),
     instrumentations: [
       {
         channelName: 'unitTest',