diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index 788d079067e995297ce8c6f2440663715ebe3256..4b27ab53c7de179ba8a4a55e5de4df63929012a5 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -6,6 +6,10 @@ For a detailed view of what's changed, refer to the {url-repo}/commits[commit hi
 
 == Unreleased
 
+=== Changed
+
+* exclude `env` property when exporting playbook to json or yaml (#32)
+
 === Fixed
 
 * account for null value on env key or env entry
diff --git a/packages/collector-extension/lib/index.js b/packages/collector-extension/lib/index.js
index 22fad0d39ecfecd5c2330a1c14db6d772cc68d90..ecaef8a6c6a32d34a33d6d0611ea8c1287a82ab9 100644
--- a/packages/collector-extension/lib/index.js
+++ b/packages/collector-extension/lib/index.js
@@ -73,6 +73,8 @@ module.exports.register = function ({ config: { createWorktrees = 'auto', keepWo
                 let envModified = !('NODE' in playbookEnv)
                 let env = envModified ? Object.assign({ NODE: process.execPath }, playbookEnv) : playbookEnv
                 let envConfig = run.env
+                Object.isFrozen(playbook) &&
+                  Object.defineProperty((playbook = Object.assign({}, playbook)), 'env', { enumerable: false })
                 const contextVars = { origin, playbook, env }
                 if (envConfig && typeof envConfig === 'object') {
                   if (!Array.isArray(envConfig)) {
diff --git a/packages/collector-extension/test/collector-extension-test.js b/packages/collector-extension/test/collector-extension-test.js
index aa8a5012190117287900d1ace8443ee5c6b614b2..9b4c48a51eb42c325de3a9f790502cbfeac648ce 100644
--- a/packages/collector-extension/test/collector-extension-test.js
+++ b/packages/collector-extension/test/collector-extension-test.js
@@ -1196,6 +1196,10 @@ describe('collector extension', () => {
           {
             command: '$NODE .gen-using-env.js',
             env: [
+              {
+                name: 'ANTORA_PLAYBOOK',
+                value: '$' + '{{ playbook as json }}',
+              },
               {
                 name: 'ANTORA_COLLECTOR_ORIGIN',
                 value: '$' + '{{ origin as json }}',
@@ -1217,7 +1221,8 @@ describe('collector extension', () => {
         repoName: 'test-at-root',
         collectorConfig,
         before: (contentAggregate, playbook) => {
-          playbook.site = { title: 'My Site' }
+          playbook.site = { title: 'My Site', url: 'https://docs.example.org' }
+          Object.freeze(playbook)
           expect(contentAggregate).to.have.lengthOf(1)
         },
         after: (contentAggregate) => {
@@ -1229,6 +1234,8 @@ describe('collector extension', () => {
             refname:: main
             worktree:: ${expectedWorktree}
             site title:: My Site (test)
+            site url:: https://docs.example.org
+            env in playbook:: false
           `
           expect(bucket.files).to.have.lengthOf(1)
           expect(bucket.files[0].path).to.equal('modules/ROOT/pages/index.adoc')
diff --git a/packages/collector-extension/test/fixtures/test-at-root/.gen-using-env.js b/packages/collector-extension/test/fixtures/test-at-root/.gen-using-env.js
index 999bc27d19a456ae5902ea6c9c1c7ad1735c55b7..b9a25392409e95bd155fbcc16ee595ff60ca111d 100644
--- a/packages/collector-extension/test/fixtures/test-at-root/.gen-using-env.js
+++ b/packages/collector-extension/test/fixtures/test-at-root/.gen-using-env.js
@@ -12,6 +12,7 @@ const fsp = require('node:fs/promises')
     contents = `= Refname\n\n${process.env.refname}`
   } else {
     const origin = JSON.parse(process.env.ANTORA_COLLECTOR_ORIGIN || '{}')
+    const playbook = JSON.parse(process.env.ANTORA_PLAYBOOK || '{}')
     contents = [
       '= Origin Info',
       '',
@@ -19,6 +20,8 @@ const fsp = require('node:fs/promises')
       'refname:: ' + origin.refname,
       'worktree:: ' + process.env.ANTORA_COLLECTOR_WORKTREE,
       'site title:: ' + process.env.ANTORA_COLLECTOR_SITE_TITLE,
+      'site url:: ' + playbook.site.url,
+      'env in playbook:: ' + ('env' in playbook),
     ].join('\n')
   }
   await fsp.writeFile('build/modules/ROOT/pages/index.adoc', contents, 'utf8')