diff --git a/lib/manager/npm/post-update/pnpm.ts b/lib/manager/npm/post-update/pnpm.ts
index 09d32ba093961e7dcb07028cff30179c314fdf1c..9b1d5383fd58e4d0921db50812326648fbc6f47d 100644
--- a/lib/manager/npm/post-update/pnpm.ts
+++ b/lib/manager/npm/post-update/pnpm.ts
@@ -26,8 +26,8 @@ export async function generateLockFile(
     const execOptions: ExecOptions = {
       cwd,
       extraEnv: {
-        NPM_CONFIG_CACHE: process.env.NPM_CONFIG_CACHE,
-        npm_config_store: process.env.npm_config_store,
+        NPM_CONFIG_CACHE: env.NPM_CONFIG_CACHE,
+        npm_config_store: env.npm_config_store,
       },
       docker: {
         image: 'renovate/node',
diff --git a/lib/manager/npm/post-update/yarn.spec.ts b/lib/manager/npm/post-update/yarn.spec.ts
index 05bfa1d34541406b1e39072f7c4c8bb39e6c04fb..09f50f5eaa994c2c8fb9ce9d8b7346e5fd1466b3 100644
--- a/lib/manager/npm/post-update/yarn.spec.ts
+++ b/lib/manager/npm/post-update/yarn.spec.ts
@@ -98,7 +98,7 @@ describe(getName(__filename), () => {
     fs.readFile.mockImplementationOnce(() => {
       throw new Error('not-found');
     });
-    const res = await yarnHelper.generateLockFile('some-dir');
+    const res = await yarnHelper.generateLockFile('some-dir', {});
     expect(fs.readFile).toHaveBeenCalledTimes(2);
     expect(res.error).toBe(true);
     expect(res.lockFile).not.toBeDefined();
diff --git a/lib/manager/npm/post-update/yarn.ts b/lib/manager/npm/post-update/yarn.ts
index 093c6694ef14d196b6385d8d88d2e3345ce0d4cb..806747dcd133342477c03a046d8b0b602683151a 100644
--- a/lib/manager/npm/post-update/yarn.ts
+++ b/lib/manager/npm/post-update/yarn.ts
@@ -32,7 +32,7 @@ export async function hasYarnOfflineMirror(cwd: string): Promise<boolean> {
 
 export async function generateLockFile(
   cwd: string,
-  env?: NodeJS.ProcessEnv,
+  env: NodeJS.ProcessEnv,
   config: PostUpdateConfig = {},
   upgrades: Upgrade[] = []
 ): Promise<GenerateLockFileResult> {
@@ -58,8 +58,8 @@ export async function generateLockFile(
     const execOptions: ExecOptions = {
       cwd,
       extraEnv: {
-        NPM_CONFIG_CACHE: env?.NPM_CONFIG_CACHE,
-        npm_config_store: env?.npm_config_store,
+        NPM_CONFIG_CACHE: env.NPM_CONFIG_CACHE,
+        npm_config_store: env.npm_config_store,
       },
       docker: {
         image: 'renovate/node',