diff --git a/hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/mutable/MapStringConverter.java b/hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/mutable/MapStringConverter.java
new file mode 100644
index 000000000000..8f43918de57f
--- /dev/null
+++ b/hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/mutable/MapStringConverter.java
@@ -0,0 +1,39 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or http://www.gnu.org/licenses/lgpl-2.1.html
+ */
+
+package org.hibernate.test.bytecode.enhancement.mutable;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.stream.Collectors;
+import javax.persistence.AttributeConverter;
+
+public class MapStringConverter implements AttributeConverter<Map<String, String>, String> {
+
+	@Override
+	public String convertToDatabaseColumn(Map<String, String> attribute) {
+		if ( attribute == null ) {
+			return null;
+		}
+		return attribute.entrySet().stream()
+				.map( entry -> entry.getKey() + ";" + entry.getValue() )
+				.collect( Collectors.joining( ";" ) );
+	}
+
+	@Override
+	public Map<String, String> convertToEntityAttribute(String dbData) {
+		if ( dbData == null ) {
+			return null;
+		}
+		String[] strings = dbData.split( ";" );
+		Map<String, String> map = new HashMap<>();
+		for ( int i = 0; i < strings.length; i += 2 ) {
+			map.put( strings[i], strings[i + 1] );
+		}
+		return map;
+	}
+}
\ No newline at end of file
diff --git a/hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/mutable/MutableTypeEnhancementTestCase.java b/hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/mutable/MutableTypeEnhancementTestCase.java
new file mode 100644
index 000000000000..9044b32c292b
--- /dev/null
+++ b/hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/mutable/MutableTypeEnhancementTestCase.java
@@ -0,0 +1,50 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or http://www.gnu.org/licenses/lgpl-2.1.html
+ */
+
+package org.hibernate.test.bytecode.enhancement.mutable;
+
+import java.util.Date;
+
+import org.hibernate.testing.TestForIssue;
+import org.hibernate.testing.bytecode.enhancement.BytecodeEnhancerRunner;
+import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(BytecodeEnhancerRunner.class)
+public class MutableTypeEnhancementTestCase extends BaseCoreFunctionalTestCase {
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class[] { TestEntity.class };
+	}
+
+	@Test
+	@TestForIssue(jiraKey = "HHH-14329")
+	public void testMutateMutableTypeObject() throws Exception {
+		inTransaction( entityManager -> {
+			TestEntity e = new TestEntity();
+			e.setId( 1L );
+			e.setDate( new Date() );
+			e.getTexts().put( "a", "abc" );
+			entityManager.persist( e );
+		} );
+
+		inTransaction( entityManager -> {
+			TestEntity e = entityManager.find( TestEntity.class, 1L );
+			e.getDate().setTime( 0 );
+			e.getTexts().put( "a", "def" );
+		} );
+
+		inTransaction( entityManager -> {
+			TestEntity e = entityManager.find( TestEntity.class, 1L );
+			Assert.assertEquals( 0L, e.getDate().getTime() );
+			Assert.assertEquals( "def", e.getTexts().get( "a" ) );
+		} );
+	}
+}
diff --git a/hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/mutable/TestEntity.java b/hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/mutable/TestEntity.java
new file mode 100644
index 000000000000..3947045b6f75
--- /dev/null
+++ b/hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/mutable/TestEntity.java
@@ -0,0 +1,56 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or http://www.gnu.org/licenses/lgpl-2.1.html
+ */
+package org.hibernate.test.bytecode.enhancement.mutable;
+
+import java.util.Date;
+import java.util.HashMap;
+import java.util.Map;
+import javax.persistence.Basic;
+import javax.persistence.Column;
+import javax.persistence.Convert;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Temporal;
+import javax.persistence.TemporalType;
+
+@Entity
+public class TestEntity {
+	@Id
+	private Long id;
+
+	@Temporal(TemporalType.TIMESTAMP)
+	private Date date;
+
+	@Basic
+	@Column(name = "TEXTS")
+	@Convert(converter = MapStringConverter.class)
+	private Map<String, String> texts = new HashMap<>();
+
+	public Long getId() {
+		return id;
+	}
+
+	public void setId(Long id) {
+		this.id = id;
+	}
+
+	public Date getDate() {
+		return date;
+	}
+
+	public void setDate(Date date) {
+		this.date = date;
+	}
+
+	public Map<String, String> getTexts() {
+		return texts;
+	}
+
+	public void setTexts(Map<String, String> texts) {
+		this.texts = texts;
+	}
+}