diff --git a/src/test/java/org/apache/commons/collections4/IterableUtilsTest.java b/src/test/java/org/apache/commons/collections4/IterableUtilsTest.java
index 86db1b5ff..7fd48737d 100644
--- a/src/test/java/org/apache/commons/collections4/IterableUtilsTest.java
+++ b/src/test/java/org/apache/commons/collections4/IterableUtilsTest.java
@@ -301,7 +301,7 @@ public class IterableUtilsTest {
         assertEquals(-1, index);
         assertEquals(-1, IterableUtils.indexOf(null, testPredicate));
         try {
-            assertNull(IterableUtils.indexOf(iterableA, null));
+            IterableUtils.indexOf(iterableA, null);
             fail("expecting NullPointerException");
         } catch (final NullPointerException npe) {
             // expected
diff --git a/src/test/java/org/apache/commons/collections4/IteratorUtilsTest.java b/src/test/java/org/apache/commons/collections4/IteratorUtilsTest.java
index a27ad040d..70252a6e0 100644
--- a/src/test/java/org/apache/commons/collections4/IteratorUtilsTest.java
+++ b/src/test/java/org/apache/commons/collections4/IteratorUtilsTest.java
@@ -1064,7 +1064,7 @@ public class IteratorUtilsTest {
         assertEquals(-1, index);
         assertEquals(-1, IteratorUtils.indexOf(null, testPredicate));
         try {
-            assertNull(IteratorUtils.indexOf(iterableA.iterator(), null));
+            IteratorUtils.indexOf(iterableA.iterator(), null);
             fail("expecting NullPointerException");
         } catch (final NullPointerException npe) {
             // expected