diff --git a/programs/mutant-1/swen90006/passbook/PassBook.java b/programs/mutant-1/swen90006/passbook/PassBook.java
index 94e2dfdcd19284dafa914ed1214ff926ea3318da..7aff09bcebf8a2ce928e89d6de312a9210ce291f 100644
--- a/programs/mutant-1/swen90006/passbook/PassBook.java
+++ b/programs/mutant-1/swen90006/passbook/PassBook.java
@@ -93,7 +93,7 @@ public class PassBook
boolean containsNumber = false;
for (int i = 0; i < passphrase.length(); i++) {
- if ('a' <= passphrase.charAt(i) && passphrase.charAt(i) <= 'z') {
+ if ('a' < passphrase.charAt(i) && passphrase.charAt(i) <= 'z') {
containsLowerCase = true;
}
else if ('A' <= passphrase.charAt(i) && passphrase.charAt(i) <= 'Z') {