diff --git a/lib/manager/npm/post-update/index.js b/lib/manager/npm/post-update/index.js
index 1daebc0ff590a611e1e386f2605e34a0fb2aabc4..c9e52760b64e4e5b89ffcf70657e38bcb7e1437d 100644
--- a/lib/manager/npm/post-update/index.js
+++ b/lib/manager/npm/post-update/index.js
@@ -33,7 +33,8 @@ function determineLockFileDirs(config, packageFiles) {
           packageFile.lernaDir &&
           (packageFile.npmLock || packageFile.yarnLock)
         ) {
-          lernaDirs.push(packageFile.lernaDir);
+          logger.info('Skipping lerna lockFileMaintenance - unsupported');
+          // TODO: lernaDirs.push(packageFile.lernaDir);
         } else {
           yarnLockDirs.push(packageFile.yarnLock);
           npmLockDirs.push(packageFile.npmLock);
@@ -452,10 +453,6 @@ async function getAdditionalFiles(config, packageFiles) {
     } else {
       lockFile = config.yarnLock || 'yarn.lock';
     }
-    if (!config.lernaClient) {
-      logger.debug({ config }, 'lernaClient debug');
-      throw new Error('internal-error');
-    }
     logger.debug(
       { lernaClient: config.lernaClient, lockFile },
       'Generating lock files using lerna'
diff --git a/lib/manager/npm/post-update/lerna.js b/lib/manager/npm/post-update/lerna.js
index 88d71df61c32e30b4a1eab36ada4ac244bc2a1a0..d497a832699c32b9370f1326abf16c01ace38d6d 100644
--- a/lib/manager/npm/post-update/lerna.js
+++ b/lib/manager/npm/post-update/lerna.js
@@ -5,6 +5,10 @@ module.exports = {
 };
 
 async function generateLockFiles(lernaClient, tmpDir, env) {
+  if (!lernaClient) {
+    logger.warn('No lernaClient specified - returning');
+    return { error: false };
+  }
   logger.debug(`Spawning lerna with ${lernaClient} to create lock files`);
   let stdout;
   let stderr;
diff --git a/test/workers/branch/lock-files/lerna.spec.js b/test/workers/branch/lock-files/lerna.spec.js
index 7c3cae78625d210a746450ab0fd669adc594dff5..576e39d9feb87f01aabb84f50e4b96dc18ced80b 100644
--- a/test/workers/branch/lock-files/lerna.spec.js
+++ b/test/workers/branch/lock-files/lerna.spec.js
@@ -5,6 +5,10 @@ jest.mock('child-process-promise');
 const { exec } = require('child-process-promise');
 
 describe('generateLockFiles()', () => {
+  it('returns if no lernaClient', async () => {
+    const res = await lernaHelper.generateLockFiles(undefined, 'some-dir', {});
+    expect(res.error).toBe(false);
+  });
   it('generates package-lock.json files', async () => {
     platform.getFile.mockReturnValueOnce(
       JSON.stringify({ dependencies: { lerna: '2.0.0' } })