diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/bytecode/enhancement/merge/MergeTest.java b/hibernate-core/src/test/java/org/hibernate/orm/test/bytecode/enhancement/merge/MergeTest.java
new file mode 100644
index 0000000000..f34c0d1b39
--- /dev/null
+++ b/hibernate-core/src/test/java/org/hibernate/orm/test/bytecode/enhancement/merge/MergeTest.java
@@ -0,0 +1,240 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.orm.test.bytecode.enhancement.merge;
+
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Version;
+import org.hibernate.testing.bytecode.enhancement.extension.BytecodeEnhanced;
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+@DomainModel(
+		annotatedClasses = {
+				MergeTest.Parent.class,
+				MergeTest.Child.class,
+				MergeTest.Owned.class,
+				MergeTest.Owner.class,
+		}
+)
+@SessionFactory
+@BytecodeEnhanced(runNotEnhancedAsWell = true)
+public class MergeTest {
+
+	@AfterEach
+	public void tearDown(SessionFactoryScope scope) {
+		scope.inTransaction(
+				session -> {
+					session.createQuery( "delete from Child" ).executeUpdate();
+					session.createQuery( "delete from Parent" ).executeUpdate();
+				}
+		);
+	}
+
+	@Test
+	public void testMerge(SessionFactoryScope scope) {
+		Parent parent = scope.fromTransaction(
+				session -> {
+					Parent p = new Parent( "a" );
+					Child child = new Child( p, "b" );
+					session.persist( p );
+					return p;
+
+				}
+		);
+
+		scope.inTransaction( session -> {
+			Child child2 = new Child( parent, "c" );
+			session.merge( parent );
+		} );
+
+		scope.inTransaction( session -> {
+			Parent saved = session.get( Parent.class, parent.getId() );
+			assertThat( saved.getChildren().size() ).isEqualTo( 2 );
+		} );
+	}
+
+	@Test
+	public void testMerge2(SessionFactoryScope scope) {
+		Parent parent = scope.fromTransaction(
+				session -> {
+					Parent p = new Parent( "a" );
+					Child child = new Child( p, "b" );
+					session.persist( p );
+					return p;
+
+				}
+		);
+
+		scope.inTransaction( session -> {
+			Child child2 = new Child( parent, "c" );
+			session.merge( parent );
+		} );
+
+		scope.inTransaction( session -> {
+			Parent saved = session.get( Parent.class, parent.getId() );
+			assertThat( saved.getChildren().size() ).isEqualTo( 2 );
+		} );
+	}
+
+	@Test
+	void testMerge3(SessionFactoryScope scope) {
+		Long ownerId = scope.fromTransaction( session -> {
+			Owner owner = new Owner( "a" );
+			owner.addOwned( new Owned() );
+			session.persist( owner );
+			return owner.getId();
+		} );
+
+		scope.inTransaction( session -> {
+			Owner owner2 = new Owner( ownerId, "a" );
+			owner2.addOwned( new Owned() );
+			session.merge( owner2 );
+			session.flush();
+		} );
+	}
+
+	@Test
+	void testMerge4(SessionFactoryScope scope) {
+		Long ownerId = scope.fromTransaction( session -> {
+			Owner owner = new Owner(  );
+			owner.addOwned( new Owned() );
+			session.persist( owner );
+			return owner.getId();
+		} );
+
+		scope.inTransaction( session -> {
+			Owner owner2 = new Owner(  );
+			owner2.id = ownerId;
+			owner2.owneds.add( new Owned() );
+			session.merge( owner2 );
+			session.flush();
+		} );
+	}
+
+	@Entity(name = "Parent")
+	public static class Parent {
+
+		@Id
+		@GeneratedValue
+		public Long id;
+
+		public Long getId() {
+			return id;
+		}
+
+		private String name;
+
+		@Version
+		@Column(name = "VERSION_COLUMN")
+		private long version;
+
+		public Parent() {
+		}
+
+		public Parent(String name) {
+			this.name = name;
+		}
+
+		@OneToMany(mappedBy = "parent", cascade = CascadeType.ALL)
+		private Set<Child> children = new LinkedHashSet<>();
+
+		public Set<Child> getChildren() {
+			return children;
+		}
+	}
+
+	@Entity(name = "Child")
+	public static class Child {
+
+		@Id
+		@GeneratedValue
+		public Long id;
+
+		public Long getId() {
+			return id;
+		}
+
+		@ManyToOne
+		private Parent parent;
+
+		private String name;
+
+		public Child() {
+		}
+
+		public Child(Parent parent, String name) {
+			this.parent = parent;
+			parent.children.add( this );
+			this.name = name;
+		}
+	}
+
+	@Entity(name = "Owned")
+	public static class Owned {
+
+		@Id
+		@GeneratedValue
+		private Long id;
+
+		private String name;
+
+		public Owned() {
+		}
+
+		public Owned(String name) {
+			this.name = name;
+		}
+	}
+
+	@Entity(name = "Owner")
+	public static class Owner {
+
+		@Id
+		@GeneratedValue
+		private Long id;
+
+		private String name;
+
+		@OneToMany(cascade = CascadeType.ALL)
+		private List<Owned> owneds = new ArrayList<>();
+
+		public Owner() {
+		}
+
+		public Owner(String name) {
+			this.name = name;
+		}
+
+		public Owner(Long id, String name) {
+			this.id = id;
+			this.name = name;
+		}
+
+		public void addOwned(Owned owned) {
+			owneds.add( owned );
+		}
+
+		public Long getId() {
+			return id;
+		}
+	}
+
+}