diff --git a/core-kotlin-2/src/test/kotlin/com/baeldung/lists/ListsUnitTest.kt b/core-kotlin-2/src/test/kotlin/com/baeldung/lists/ListsUnitTest.kt
index 1e7136d08b..6fa7983689 100644
--- a/core-kotlin-2/src/test/kotlin/com/baeldung/lists/ListsUnitTest.kt
+++ b/core-kotlin-2/src/test/kotlin/com/baeldung/lists/ListsUnitTest.kt
@@ -2,6 +2,7 @@ package com.baeldung.lists
 
 import org.junit.jupiter.api.Test
 import kotlin.test.assertEquals
+import kotlin.test.assertFalse
 import kotlin.test.assertTrue
 
 class ListsUnitTest {
@@ -26,7 +27,8 @@ class ListsUnitTest {
     fun whenFilterNotWithPredicate_thenMatchingItemsAreReturned() {
         //Returns a list containing only elements not matching the given predicate.
         val theMehBatmans = batmans.filterNot { actor -> actor.contains("a") }
-        assertTrue(!theMehBatmans.contains("Christian Bale") && !theMehBatmans.contains("Michael Keaton"))
+        assertFalse(theMehBatmans.contains("Christian Bale") && theMehBatmans.contains("Michael Keaton"))
+        assertTrue(theMehBatmans.contains("Ben Affleck") && theMehBatmans.contains("George Clooney"))
     }
 
 }
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