diff --git a/src/main/java/seedu/address/model/student/predicates/StarWithinBoundsPredicate.java b/src/main/java/seedu/address/model/student/predicates/StarWithinBoundsPredicate.java
index 594eadab4c5..1110d124dd7 100644
--- a/src/main/java/seedu/address/model/student/predicates/StarWithinBoundsPredicate.java
+++ b/src/main/java/seedu/address/model/student/predicates/StarWithinBoundsPredicate.java
@@ -19,6 +19,7 @@ public class StarWithinBoundsPredicate implements Predicate<Student> {
      * @param value
      */
     public StarWithinBoundsPredicate(String operator, Integer value) {
+        assert(value > -1);
         this.operator = operator;
         this.value = value;
     }