diff --git a/junit-platform-commons/src/main/java/org/junit/platform/commons/util/CollectionUtils.java b/junit-platform-commons/src/main/java/org/junit/platform/commons/util/CollectionUtils.java
index c4b790e2f20b..d563c7f934e2 100644
--- a/junit-platform-commons/src/main/java/org/junit/platform/commons/util/CollectionUtils.java
+++ b/junit-platform-commons/src/main/java/org/junit/platform/commons/util/CollectionUtils.java
@@ -36,7 +36,9 @@
 import java.util.stream.Stream;
 
 import org.apiguardian.api.API;
+import org.junit.platform.commons.JUnitException;
 import org.junit.platform.commons.PreconditionViolationException;
+import org.junit.platform.commons.function.Try;
 
 /**
  * Collection of utilities for working with {@link Collection Collections}.
@@ -140,12 +142,12 @@ public static boolean isConvertibleToStream(Class<?> type) {
 				|| LongStream.class.isAssignableFrom(type)//
 				|| Iterable.class.isAssignableFrom(type)//
 				|| Iterator.class.isAssignableFrom(type)//
-				|| Spliterator.class.isAssignableFrom(type)//
 				|| Object[].class.isAssignableFrom(type)//
 				|| (type.isArray() && type.getComponentType().isPrimitive())//
 				|| Arrays.stream(type.getMethods())//
+						.filter(m -> m.getName().equals("iterator"))//
 						.map(Method::getReturnType)//
-						.anyMatch(returnType -> returnType == Iterator.class || returnType == Spliterator.class));
+						.anyMatch(returnType -> returnType == Iterator.class));
 	}
 
 	/**
@@ -159,10 +161,9 @@ public static boolean isConvertibleToStream(Class<?> type) {
 	 * <li>{@link Collection}</li>
 	 * <li>{@link Iterable}</li>
 	 * <li>{@link Iterator}</li>
-	 * <li>{@link Spliterator}</li>
 	 * <li>{@link Object} array</li>
 	 * <li>primitive array</li>
-	 * <li>An object that contains an iterator or spliterator returning method</li>
+	 * <li>An object that contains a method with name `iterator` returning an Iterator object</li>
 	 * </ul>
 	 *
 	 * @param object the object to convert into a stream; never {@code null}
@@ -194,9 +195,6 @@ public static Stream<?> toStream(Object object) {
 		if (object instanceof Iterator) {
 			return stream(spliteratorUnknownSize((Iterator<?>) object, ORDERED), false);
 		}
-		if (object instanceof Spliterator) {
-			return stream((Spliterator<?>) object, false);
-		}
 		if (object instanceof Object[]) {
 			return Arrays.stream((Object[]) object);
 		}
@@ -212,7 +210,31 @@ public static Stream<?> toStream(Object object) {
 		if (object.getClass().isArray() && object.getClass().getComponentType().isPrimitive()) {
 			return IntStream.range(0, Array.getLength(object)).mapToObj(i -> Array.get(object, i));
 		}
-		return StreamUtils.tryConvertToStreamByReflection(object);
+		return tryConvertToStreamByReflection(object);
+	}
+
+	private static Stream<?> tryConvertToStreamByReflection(Object object) {
+		Preconditions.notNull(object, "Object must not be null");
+		try {
+			String name = "iterator";
+			Method method = object.getClass().getMethod(name);
+			if (method.getReturnType() == Iterator.class) {
+				return stream(() -> tryIteratorToSpliterator(object, method), ORDERED, false);
+			}
+			else {
+				throw new PreconditionViolationException(
+					"Method with name 'iterator' does not return " + Iterator.class.getName());
+			}
+		}
+		catch (NoSuchMethodException | IllegalStateException e) {
+			throw new PreconditionViolationException(//
+				"Cannot convert instance of " + object.getClass().getName() + " into a Stream: " + object, e);
+		}
+	}
+
+	private static Spliterator<?> tryIteratorToSpliterator(Object object, Method method) {
+		return Try.call(() -> spliteratorUnknownSize((Iterator<?>) method.invoke(object), ORDERED))//
+				.getOrThrow(e -> new JUnitException("Cannot invoke method " + method.getName() + " onto " + object, e));//
 	}
 
 	/**
diff --git a/junit-platform-commons/src/main/java/org/junit/platform/commons/util/StreamUtils.java b/junit-platform-commons/src/main/java/org/junit/platform/commons/util/StreamUtils.java
deleted file mode 100644
index 1c629d251f71..000000000000
--- a/junit-platform-commons/src/main/java/org/junit/platform/commons/util/StreamUtils.java
+++ /dev/null
@@ -1,109 +0,0 @@
-/*
- * Copyright 2015-2023 the original author or authors.
- *
- * All rights reserved. This program and the accompanying materials are
- * made available under the terms of the Eclipse Public License v2.0 which
- * accompanies this distribution and is available at
- *
- * https://www.eclipse.org/legal/epl-v20.html
- */
-
-package org.junit.platform.commons.util;
-
-import static java.util.Spliterator.ORDERED;
-import static java.util.Spliterators.spliteratorUnknownSize;
-import static java.util.stream.StreamSupport.stream;
-
-import java.lang.reflect.Method;
-import java.util.Arrays;
-import java.util.Iterator;
-import java.util.Optional;
-import java.util.Spliterator;
-import java.util.stream.Stream;
-
-import org.junit.platform.commons.JUnitException;
-import org.junit.platform.commons.PreconditionViolationException;
-import org.junit.platform.commons.function.Try;
-
-/**
- * Collection of utilities for working with {@link Stream Streams}.
- *
- * @since 5.10
- */
-final class StreamUtils {
-
-	private StreamUtils() {
-	}
-
-	static Stream<?> tryConvertToStreamByReflection(Object object) {
-		Preconditions.notNull(object, "Object must not be null");
-		Class<?> theClass = object.getClass();
-		try {
-			String name = "iterator";
-			Method method = theClass.getMethod(name);
-			if (method.getReturnType() == Iterator.class) {
-				return stream(() -> tryIteratorToSpliterator(object, method), ORDERED, false);
-			}
-			else {
-				throw new IllegalStateException(
-					"Method with name 'iterator' does not return " + Iterator.class.getName());
-			}
-		}
-		catch (NoSuchMethodException | IllegalStateException e) {
-			return tryConvertToStreamBySpliterator(object, e);
-		}
-	}
-
-	private static Stream<?> tryConvertToStreamBySpliterator(Object object, Exception e) {
-		try {
-			String name = "spliterator";
-			Method method = object.getClass().getMethod(name);
-			if (method.getReturnType() == Spliterator.class) {
-				return stream(() -> tryInvokeSpliterator(object, method), ORDERED, false);
-			}
-			else {
-				throw new IllegalStateException(
-					"Method with name '" + name + "' does not return " + Spliterator.class.getName());
-			}
-		}
-		catch (NoSuchMethodException | IllegalStateException ex) {
-			ex.addSuppressed(e);
-			return tryConvertByIteratorSpliteratorReturnType(object, ex);
-		}
-	}
-
-	private static Stream<?> tryConvertByIteratorSpliteratorReturnType(Object object, Exception ex) {
-		return streamFromSpliteratorSupplier(object)//
-				.orElseGet(() -> streamFromIteratorSupplier(object)//
-						.orElseThrow(() -> //
-						new PreconditionViolationException(//
-							"Cannot convert instance of " + object.getClass().getName() + " into a Stream: " + object,
-							ex)));
-	}
-
-	private static Optional<Stream<?>> streamFromSpliteratorSupplier(Object object) {
-		return Arrays.stream(object.getClass().getMethods())//
-				.filter(m -> m.getReturnType() == Spliterator.class)//
-				.findFirst()//
-				.map(m -> stream(() -> tryInvokeSpliterator(object, m), ORDERED, false));//
-	}
-
-	private static Optional<Stream<?>> streamFromIteratorSupplier(Object object) {
-		return Arrays.stream(object.getClass().getMethods())//
-				.filter(m -> m.getReturnType() == Iterator.class)//
-				.findFirst()//
-				.map(m -> stream(() -> tryIteratorToSpliterator(object, m), ORDERED, false));//
-	}
-
-	private static Spliterator<?> tryInvokeSpliterator(Object object, Method method) {
-		return Try.call(() -> (Spliterator<?>) method.invoke(object))//
-				.getOrThrow(e -> new JUnitException("Cannot invoke method " + method.getName() + " onto " + object, e));//
-	}
-
-	private static Spliterator<?> tryIteratorToSpliterator(Object object, Method method) {
-		return Try.call(() -> method.invoke(object))//
-				.andThen(m -> Try.call(() -> spliteratorUnknownSize((Iterator<?>) m, ORDERED)))//
-				.getOrThrow(e -> new JUnitException("Cannot invoke method " + method.getName() + " onto " + object, e));//
-	}
-
-}
diff --git a/platform-tests/src/test/java/org/junit/platform/commons/util/CollectionUtilsTests.java b/platform-tests/src/test/java/org/junit/platform/commons/util/CollectionUtilsTests.java
index 642159695910..d4a5e41efb5e 100644
--- a/platform-tests/src/test/java/org/junit/platform/commons/util/CollectionUtilsTests.java
+++ b/platform-tests/src/test/java/org/junit/platform/commons/util/CollectionUtilsTests.java
@@ -99,9 +99,7 @@ void toUnmodifiableListThrowsOnMutation() {
 			Collection.class, //
 			Iterable.class, //
 			Iterator.class, //
-			Spliterator.class, //
-			MySpliteratorProvider.class, //
-			MyIteratorProvider.class, //
+			IteratorProvider.class, //
 			Object[].class, //
 			String[].class, //
 			int[].class, //
@@ -123,12 +121,11 @@ static Stream<Object> objectsConvertibleToStreams() {
 			Stream.of("cat", "dog"), //
 			DoubleStream.of(42.3), //
 			IntStream.of(99), //
-			LongStream.of(100000000), //
+			LongStream.of(100_000_000), //
 			Set.of(1, 2, 3), //
 			Arguments.of((Object) new Object[] { 9, 8, 7 }), //
 			new int[] { 5, 10, 15 }, //
-			MySpliteratorProvider.of(new String[] { "mouse", "bear" }), //
-			MyIteratorProvider.of(new Integer[] { 1, 2, 3, 4, 5 })//
+			IteratorProvider.of(new Integer[] { 1, 2, 3, 4, 5 })//
 		);
 	}
 
@@ -139,6 +136,8 @@ static Stream<Object> objectsConvertibleToStreams() {
 			Object.class, //
 			Integer.class, //
 			String.class, //
+			IteratorProviderNotUsable.class, //
+			Spliterator.class, //
 			int.class, //
 			boolean.class //
 	})
@@ -251,20 +250,10 @@ void toStreamWithIterator() {
 		assertThat(result).containsExactly("foo", "bar");
 	}
 
-	@Test
-	@SuppressWarnings("unchecked")
-	void toStreamWithSpliterator() {
-		final var input = List.of("foo", "bar").spliterator();
-
-		final var result = (Stream<String>) CollectionUtils.toStream(input);
-
-		assertThat(result).containsExactly("foo", "bar");
-	}
-
 	@Test
 	@SuppressWarnings("unchecked")
 	void toStreamWithIteratorProvider() {
-		final var input = MyIteratorProvider.of(new String[] { "foo", "bar" });
+		final var input = IteratorProvider.of(new String[] { "foo", "bar" });
 
 		final var result = (Stream<String>) CollectionUtils.toStream(input);
 
@@ -272,13 +261,11 @@ void toStreamWithIteratorProvider() {
 	}
 
 	@Test
-	@SuppressWarnings("unchecked")
-	void toStreamWithSpliteratorProvider() {
-		final var input = MySpliteratorProvider.of(new String[] { "foo", "bar" });
-
-		var result = (Stream<String>) CollectionUtils.toStream(input);
+	void throwWhenIteratorNamedMethodDoesNotReturnAnIterator() {
+		var o = IteratorProviderNotUsable.of(new String[] { "Test" });
+		var e = assertThrows(PreconditionViolationException.class, () -> CollectionUtils.toStream(o));
 
-		assertThat(result).containsExactly("foo", "bar");
+		assertEquals("Method with name 'iterator' does not return java.util.Iterator", e.getMessage());
 	}
 
 	@Test
@@ -345,24 +332,29 @@ public Object convert(Object source, ParameterContext context) throws ArgumentCo
 		}
 	}
 
+	/**
+	 * An interface that has a method with name 'iterator', returning a java.util/Iterator as a return type
+	 */
 	@FunctionalInterface
-	private interface MySpliteratorProvider<T> {
+	private interface IteratorProvider<T> {
 
 		@SuppressWarnings("unused")
-		Spliterator<T> thisReturnsASpliterator();
+		Iterator<T> iterator();
 
-		static <T> MySpliteratorProvider<T> of(T[] elements) {
-			return () -> Arrays.spliterator(elements);
+		static <T> IteratorProvider<T> of(T[] elements) {
+			return () -> Spliterators.iterator(Arrays.spliterator(elements));
 		}
 	}
 
+	/**
+	 * An interface that has a method with name 'iterator', but does not return java.util/Iterator as a return type
+	 */
 	@FunctionalInterface
-	private interface MyIteratorProvider<T> {
-
+	private interface IteratorProviderNotUsable {
 		@SuppressWarnings("unused")
-		Iterator<T> thisReturnsAnIterator();
+		Object iterator();
 
-		static <T> MyIteratorProvider<T> of(T[] elements) {
+		static <T> IteratorProviderNotUsable of(T[] elements) {
 			return () -> Spliterators.iterator(Arrays.spliterator(elements));
 		}
 	}
diff --git a/platform-tests/src/test/java/org/junit/platform/commons/util/StreamUtilsTest.java b/platform-tests/src/test/java/org/junit/platform/commons/util/StreamUtilsTest.java
deleted file mode 100644
index 6fda1a6e28d9..000000000000
--- a/platform-tests/src/test/java/org/junit/platform/commons/util/StreamUtilsTest.java
+++ /dev/null
@@ -1,121 +0,0 @@
-/*
- * Copyright 2015-2023 the original author or authors.
- *
- * All rights reserved. This program and the accompanying materials are
- * made available under the terms of the Eclipse Public License v2.0 which
- * accompanies this distribution and is available at
- *
- * https://www.eclipse.org/legal/epl-v20.html
- */
-
-package org.junit.platform.commons.util;
-
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
-import java.util.Iterator;
-import java.util.List;
-import java.util.Spliterator;
-import java.util.stream.Stream;
-
-import org.junit.jupiter.api.Test;
-import org.junit.platform.commons.PreconditionViolationException;
-
-class StreamUtilsTest {
-
-	@Test
-	void throwWhenIteratorNamedMethodDoesNotReturnAnIterator() {
-		var o = IteratorProviderNotUsable.of("Test");
-		var e = assertThrows(PreconditionViolationException.class, () -> StreamUtils.tryConvertToStreamByReflection(o));
-
-		e.printStackTrace();
-		assertEquals(1, e.getCause().getSuppressed().length);
-	}
-
-	@SuppressWarnings("unchecked")
-	@Test
-	void usesSpliteratorToConvertToStream() {
-		var object = SpliteratorProvider.of(List.of("this", "is", "a", "test"));
-
-		var result = (Stream<String>) StreamUtils.tryConvertToStreamByReflection(object);
-
-		assertThat(result).containsExactly("this", "is", "a", "test");
-	}
-
-	@SuppressWarnings("unchecked")
-	@Test
-	void usesIteratorExposingMethodToConvertToStream() {
-		var object = IteratorExposing.of(List.of("this", "is", "a", "test"));
-
-		var result = (Stream<String>) StreamUtils.tryConvertToStreamByReflection(object);
-
-		assertThat(result).containsExactly("this", "is", "a", "test");
-	}
-
-	/**
-	 * An interface that has an iterator method but does not return java.util/Iterator as a return type
-	 */
-	@FunctionalInterface
-	private interface IteratorProviderNotUsable {
-		@SuppressWarnings("unused")
-		Object iterator();
-
-		static IteratorProviderNotUsable of(Object o) {
-			return () -> o;
-		}
-	}
-
-	/**
-	 * An object that exposes:
-	 * <ol>
-	 * <li>a method with name 'iterator' that does not return an iterator</li>
-	 * <li>a method with name 'spliterator' that returns a java.util.Spliterator</li>
-	 * </ol>
-	 * @param <T> The type of the spliterator
-	 */
-	@FunctionalInterface
-	private interface SpliteratorProvider<T> {
-
-		@SuppressWarnings("unused")
-		default Object iterator() {
-			return null;
-		}
-
-		@SuppressWarnings("unused")
-		Spliterator<T> spliterator();
-
-		static <T> SpliteratorProvider<T> of(Iterable<T> iterable) {
-			return iterable::spliterator;
-		}
-
-	}
-
-	/**
-	 * An object that exposes:
-	 * <ol>
-	 * <li>a method with name 'iterator' that does not return an iterator</li>
-	 * <li>a method with name 'spliterator' that does not return a java.util.Spliterator</li>
-	 * <li>a method with other name than 'iterator' returning an iterator</li>
-	 * </ol>
-	 */
-	private interface IteratorExposing<T> {
-
-		@SuppressWarnings("unused")
-		default Object iterator() {
-			return null;
-		}
-
-		@SuppressWarnings("unused")
-		default Object spliterator() {
-			return null;
-		}
-
-		@SuppressWarnings("unused")
-		Iterator<T> returnsAnIterator();
-
-		static <T> IteratorExposing<T> of(Iterable<T> iterable) {
-			return iterable::iterator;
-		}
-	}
-}