diff --git a/code/addons/themes/postinstall.js b/code/addons/themes/postinstall.js
index c84a4e88e4b4..01a9b3151e89 100644
--- a/code/addons/themes/postinstall.js
+++ b/code/addons/themes/postinstall.js
@@ -2,7 +2,7 @@ const { spawn } = require('child_process');
 
 const PACKAGE_MANAGER_TO_COMMAND = {
   npm: 'npx',
-  yarn1: 'yarn dlx',
+  yarn1: 'npx',
   yarn2: 'yarn dlx',
   pnpm: 'pnpm dlx',
 };
diff --git a/code/lib/cli/src/add.ts b/code/lib/cli/src/add.ts
index a163e1f1e34f..71437b314b1c 100644
--- a/code/lib/cli/src/add.ts
+++ b/code/lib/cli/src/add.ts
@@ -91,6 +91,6 @@ export async function add(
   await writeConfig(main);
 
   if (!options.skipPostinstall && isStorybookAddon) {
-    await postinstallAddon(addonName, { packageManager: pkgMgr });
+    await postinstallAddon(addonName, { packageManager: packageManager.type });
   }
 }