diff --git a/lib/manager/npm/post-update/index.ts b/lib/manager/npm/post-update/index.ts
index 1e7032521d28db30714a6b6627fb25ca339e48a4..5bea15ee1fa06f96f98bfb4b3fe996afa4074d70 100644
--- a/lib/manager/npm/post-update/index.ts
+++ b/lib/manager/npm/post-update/index.ts
@@ -122,18 +122,6 @@ export async function writeExistingFiles(
   config: PostUpdateConfig,
   packageFiles: AdditionalPackageFiles
 ): Promise<void> {
-  const npmrcFile = upath.join(config.localDir, '.npmrc');
-  if (is.string(config.npmrc)) {
-    logger.debug(`Writing repo .npmrc (${config.localDir})`);
-    await outputFile(npmrcFile, `${config.npmrc}\n`);
-  } else if (config.ignoreNpmrcFile) {
-    logger.debug('Removing ignored .npmrc file before artifact generation');
-    await remove(npmrcFile);
-  }
-  if (is.string(config.yarnrc)) {
-    logger.debug(`Writing repo .yarnrc (${config.localDir})`);
-    await outputFile(upath.join(config.localDir, '.yarnrc'), config.yarnrc);
-  }
   if (!packageFiles.npm) {
     return;
   }