diff --git a/lib/manager/npm/post-update/index.js b/lib/manager/npm/post-update/index.js
index c4f7e67d22b8be8c3cb574f57a95802463da7af8..27d3caed1bd855bc3cc6494b25060663e1159f27 100644
--- a/lib/manager/npm/post-update/index.js
+++ b/lib/manager/npm/post-update/index.js
@@ -338,7 +338,7 @@ async function getAdditionalFiles(config, packageFiles) {
         config.parentBranch
       );
       if (res.lockFile !== existingContent) {
-        logger.debug('package-lock.json needs updating');
+        logger.debug(`${lockFile} needs updating`);
         updatedLockFiles.push({
           name: lockFile,
           contents: res.lockFile,
diff --git a/lib/manager/npm/post-update/npm.js b/lib/manager/npm/post-update/npm.js
index 0b52a5e9508839e952907018808d776f6e8cf3f5..62f7d9f58e3ab4312edc9f7e43f68d7aa7f05f9d 100644
--- a/lib/manager/npm/post-update/npm.js
+++ b/lib/manager/npm/post-update/npm.js
@@ -52,8 +52,8 @@ async function generateLockFile(tmpDir, env, filename) {
         }
       }
     }
-    logger.debug(`Using npm: ${cmd}`);
     cmd = `${cmd} --version && ${cmd} install --package-lock-only --no-audit`;
+    logger.debug(`Using npm: ${cmd}`);
     // TODO: Switch to native util.promisify once using only node 8
     ({ stdout, stderr } = await exec(cmd, {
       cwd: tmpDir,