diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/version/DetachedEntityWithNullVersionTest.java b/hibernate-core/src/test/java/org/hibernate/orm/test/version/DetachedEntityWithNullVersionTest.java
new file mode 100644
index 0000000000..e4c1e090a3
--- /dev/null
+++ b/hibernate-core/src/test/java/org/hibernate/orm/test/version/DetachedEntityWithNullVersionTest.java
@@ -0,0 +1,433 @@
+package org.hibernate.orm.test.version;
+
+import java.util.List;
+import java.util.UUID;
+
+import org.hibernate.PropertyValueException;
+import org.hibernate.exception.ConstraintViolationException;
+
+import org.hibernate.testing.orm.junit.DialectFeatureChecks;
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.JiraKey;
+import org.hibernate.testing.orm.junit.RequiresDialectFeature;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+import jakarta.persistence.Version;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+@DomainModel(
+		annotatedClasses = {
+				DetachedEntityWithNullVersionTest.IdentityGeneratedIdItem.class,
+				DetachedEntityWithNullVersionTest.SequenceGeneratedIdItem.class,
+				DetachedEntityWithNullVersionTest.TableGeneratedIdItem.class,
+				DetachedEntityWithNullVersionTest.AssignedIdItem.class,
+				DetachedEntityWithNullVersionTest.UUIDIdItem.class,
+		}
+)
+@SessionFactory
+@JiraKey("HHH-16586")
+@RequiresDialectFeature(feature = DialectFeatureChecks.SupportsSequences.class)
+@RequiresDialectFeature(feature = DialectFeatureChecks.SupportsIdentityColumns.class)
+public class DetachedEntityWithNullVersionTest {
+
+	private static final String ITEM_INITIAL_NAME = "initial name";
+	private static final String ITEM_UPDATED_NAME = "updated name";
+
+	@Test
+	public void testMergeDetachedEntityWithIdentityId(SessionFactoryScope scope) {
+		IdentityGeneratedIdItem item = new IdentityGeneratedIdItem();
+		persistItem( scope, item );
+
+		// The Item we are going to merge has the id but version null,
+		// for generated id Hibernate can detect that the instance is not transient
+		// so because of the discrepancy of the null version
+		// that implies a transient instance an exception should be thrown
+		Assertions.assertThrows( PropertyValueException.class, () ->
+				scope.inTransaction(
+						session -> {
+							IdentityGeneratedIdItem item1 = new IdentityGeneratedIdItem();
+							item1.id = item.getId();
+							item1.setName( ITEM_UPDATED_NAME );
+							session.merge( item1 );
+						}
+				)
+		);
+
+		assertItemHasNotBeenUpdated( item, scope );
+
+		updateItem( item, scope );
+
+		assertItemHasBeenUpdated( item, scope );
+	}
+
+	@Test
+	public void testMergeDetachedEntityWithSequenceId(SessionFactoryScope scope) {
+		SequenceGeneratedIdItem item = new SequenceGeneratedIdItem();
+		persistItem( scope, item );
+
+		// The Item we are going to merge has the id but version null,
+		// for generated id Hibernate can detect that the instance is not transient
+		// so because of the discrepancy of the null version
+		// that implies a transient instance an exception should be thrown
+		Assertions.assertThrows( PropertyValueException.class, () ->
+				scope.inTransaction(
+						session -> {
+							SequenceGeneratedIdItem item1 = new SequenceGeneratedIdItem();
+							item1.id = item.getId();
+							item1.setName( ITEM_UPDATED_NAME );
+							session.merge( item1 );
+						}
+				)
+		);
+
+		assertItemHasNotBeenUpdated( item, scope );
+
+		updateItem( item, scope );
+
+		assertItemHasBeenUpdated( item, scope );
+	}
+
+	@Test
+	public void testMergeDetachedEntityWithTableGerneratedId(SessionFactoryScope scope) {
+		TableGeneratedIdItem item = new TableGeneratedIdItem();
+		persistItem( scope, item );
+
+		// The Item we are going to merge has the id but version null,
+		// for generated id Hibernate can detect that the instance is not transient
+		// so because of the discrepancy of the null version
+		// that implies a transient instance an exception should be thrown
+		Assertions.assertThrows( PropertyValueException.class, () ->
+				scope.inTransaction(
+						session -> {
+							TableGeneratedIdItem item1 = new TableGeneratedIdItem();
+							item1.id = item.getId();
+							item1.setName( ITEM_UPDATED_NAME );
+							session.merge( item1 );
+						}
+				)
+		);
+
+		assertItemHasNotBeenUpdated( item, scope );
+
+		updateItem( item, scope );
+
+		assertItemHasBeenUpdated( item, scope );
+	}
+
+	@Test
+	public void testMergeDetachedEntityWithUUIDId(SessionFactoryScope scope) {
+		UUIDIdItem item = new UUIDIdItem();
+		persistItem( scope, item );
+
+		// The Item we are going to merge has the id but version null,
+		// for generated id Hibernate can detect that the instance is not transient
+		// so because of the discrepancy of the null version
+		// that implies a transient instance an exception should be thrownAssertions.assertThrows( HibernateException.class, () ->
+		Assertions.assertThrows( PropertyValueException.class, () ->
+				scope.inTransaction(
+						session -> {
+							UUIDIdItem item1 = new UUIDIdItem();
+							item1.id = item.getId();
+							item1.setName( ITEM_UPDATED_NAME );
+							session.merge( item1 );
+						}
+				)
+		);
+
+		assertItemHasNotBeenUpdated( item, scope );
+
+		updateItem( item, scope );
+
+		assertItemHasBeenUpdated( item, scope );
+	}
+
+	@Test
+	public void testMergeDetachedEntityWithAssignedId(SessionFactoryScope scope) {
+		AssignedIdItem item = new AssignedIdItem( 1l, ITEM_INITIAL_NAME );
+		persistItem( scope, item );
+
+		// we are not setting the version but the new Item has the id of a persisted entity
+		// Hibernate for assigned id does not detect that this is a detached instance so consider it
+		// a transient instance because of the null version
+		// so a constraint exception is thrown when Hibernate tries to persist it
+		Assertions.assertThrows( ConstraintViolationException.class, () ->
+				scope.inTransaction(
+						session -> {
+							AssignedIdItem item1 = new AssignedIdItem( 1l, ITEM_UPDATED_NAME );
+							session.merge( item1 );
+						}
+				)
+		);
+
+		assertItemHasNotBeenUpdated( item, scope );
+
+		updateItem( item, scope );
+
+		assertItemHasBeenUpdated( item, scope );
+	}
+
+	private static void persistItem(SessionFactoryScope scope, ItemInterface item) {
+		scope.inTransaction(
+				session -> {
+					item.setName( ITEM_INITIAL_NAME );
+					session.persist( item );
+				}
+		);
+	}
+
+	private static void assertItemHasNotBeenUpdated(ItemInterface item, SessionFactoryScope scope) {
+		scope.inTransaction(
+				session -> {
+					List<ItemInterface> items = session.createQuery( "select it from " + item.getClass()
+							.getName() + " it" ).list();
+					assertThat( items.size() ).isEqualTo( 1 );
+					assertThat( items.get( 0 ).getName() ).isEqualTo( ITEM_INITIAL_NAME );
+				}
+		);
+	}
+
+	private static void updateItem(ItemInterface item, SessionFactoryScope scope) {
+		scope.inTransaction(
+				session -> {
+					item.setName( ITEM_UPDATED_NAME );
+					session.merge( item );
+				}
+		);
+	}
+
+	private static void assertItemHasBeenUpdated(ItemInterface item, SessionFactoryScope scope) {
+		scope.inTransaction(
+				session -> {
+					List<ItemInterface> items = session.createQuery( "select it from " + item.getClass()
+									.getName() + " it" )
+							.list();
+					assertThat( items.size() ).isEqualTo( 1 );
+					assertThat( items.get( 0 ).getName() ).isEqualTo( ITEM_UPDATED_NAME );
+				}
+		);
+	}
+
+	public interface ItemInterface {
+		Long getVersion();
+
+		void setVersion(Long version);
+
+		String getName();
+
+		void setName(String name);
+	}
+
+	@Entity(name = "IdentityGeneratedIdItem")
+	@Table(name = "ITEM_TABLE")
+	public static class IdentityGeneratedIdItem implements ItemInterface {
+
+		@Id
+		@GeneratedValue(strategy = GenerationType.IDENTITY)
+		private Long id;
+
+		@Version
+		private Long version;
+
+		private String name;
+
+		public Long getId() {
+			return id;
+		}
+
+		@Override
+		public Long getVersion() {
+			return version;
+		}
+
+		@Override
+		public void setVersion(Long version) {
+			this.version = version;
+		}
+
+		@Override
+		public String getName() {
+			return name;
+		}
+
+		@Override
+		public void setName(String name) {
+			this.name = name;
+		}
+	}
+
+	@Entity(name = "SequenceGeneratedIdItem")
+	@Table(name = "ITEM_TABLE_2")
+	public static class SequenceGeneratedIdItem implements ItemInterface {
+
+		@Id
+		@GeneratedValue(strategy = GenerationType.SEQUENCE)
+
+		private Long id;
+
+		@Version
+		private Long version;
+
+		private String name;
+
+		public Long getId() {
+			return id;
+		}
+
+		@Override
+		public Long getVersion() {
+			return version;
+		}
+
+		@Override
+		public void setVersion(Long version) {
+			this.version = version;
+		}
+
+		@Override
+		public String getName() {
+			return name;
+		}
+
+		@Override
+		public void setName(String name) {
+			this.name = name;
+		}
+	}
+
+	@Entity(name = "TableGeneratedIdItem")
+	@Table(name = "ITEM_TABLE_3")
+	public static class TableGeneratedIdItem implements ItemInterface {
+
+		@Id
+		@GeneratedValue(strategy = GenerationType.TABLE)
+		private Long id;
+
+		@Version
+		private Long version;
+
+		private String name;
+
+		public Long getId() {
+			return id;
+		}
+
+		@Override
+		public Long getVersion() {
+			return version;
+		}
+
+		@Override
+		public void setVersion(Long version) {
+			this.version = version;
+		}
+
+		@Override
+		public String getName() {
+			return name;
+		}
+
+		@Override
+		public void setName(String name) {
+			this.name = name;
+		}
+	}
+
+	@Entity(name = "AssignedIdItem")
+	@Table(name = "ITEM_TABLE_4")
+	public static class AssignedIdItem implements ItemInterface {
+
+		@Id
+		private Long id;
+
+		@Version
+		private Long version;
+
+		private String name;
+
+		public AssignedIdItem() {
+		}
+
+		public AssignedIdItem(Long id, String name) {
+			this.id = id;
+			this.name = name;
+		}
+
+		public Long getId() {
+			return id;
+		}
+
+		@Override
+		public Long getVersion() {
+			return version;
+		}
+
+		@Override
+		public void setVersion(Long version) {
+			this.version = version;
+		}
+
+		@Override
+		public String getName() {
+			return name;
+		}
+
+		@Override
+		public void setName(String name) {
+			this.name = name;
+		}
+	}
+
+	@Entity(name = "UUIDIdItem")
+	@Table(name = "ITEM_TABLE_5")
+	public static class UUIDIdItem implements ItemInterface {
+
+		@Id
+		@GeneratedValue(strategy = GenerationType.UUID)
+		private UUID id;
+
+		@Version
+		private Long version;
+
+		private String name;
+
+		public UUIDIdItem() {
+		}
+
+		public UUIDIdItem(String name) {
+			this.name = name;
+		}
+
+		public UUID getId() {
+			return id;
+		}
+
+		@Override
+		public Long getVersion() {
+			return version;
+		}
+
+		@Override
+		public void setVersion(Long version) {
+			this.version = version;
+		}
+
+		@Override
+		public String getName() {
+			return name;
+		}
+
+		@Override
+		public void setName(String name) {
+			this.name = name;
+		}
+	}
+}