diff --git a/test/java/CredentialsTest.java b/test/java/CredentialsTest.java
index bee613e..5fdb1ab 100644
--- a/test/java/CredentialsTest.java
+++ b/test/java/CredentialsTest.java
@@ -16,4 +16,10 @@ class CredentialsTest {
         assertTrue(cred.valid());
     }
 
+    @Test
+    void validWrongData() {
+        Credentials cred = new Credentials("hofmannol", "GEHEIM123");
+        assertFalse(cred.valid());
+    }
+
 }
\ No newline at end of file