diff --git a/ts/index.ts b/ts/index.ts
index fb081ef..46f6178 100644
--- a/ts/index.ts
+++ b/ts/index.ts
@@ -1,6 +1,10 @@
 import { TsTest } from './tstest.classes.tstest';
 
 export const runCli = async () => {
+  if (!process.argv[2]) {
+    console.error('You must specify a test directory as argument. Please try again.');
+    process.exit(1);
+  }
   const tsTestInstance = new TsTest(process.cwd(), process.argv[2]);
   await tsTestInstance.run();
 };