diff --git a/programs/mutant-5/swen90006/passbook/PassBook.java b/programs/mutant-5/swen90006/passbook/PassBook.java
index 3e95eacb92937e614ab7f3997b26ad3f9bf27d64..3a33d41e67cc3b4f27f9117b085ece56f258d6a0 100644
--- a/programs/mutant-5/swen90006/passbook/PassBook.java
+++ b/programs/mutant-5/swen90006/passbook/PassBook.java
@@ -84,7 +84,7 @@ public class PassBook
 	}
 	//check the passphrase strength
 	else {
-	    	if(passbookUsername.length()<1) {
+	    	if(passbookUsername.length()==0) {
 			throw new WeakPassphraseException(passphrase);
 		}
 	    if (passphrase.length() < MINIMUM_PASSPHRASE_LENGTH) {