diff --git a/hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/lazy/LazyOneToManyWithEqualsImplementationTest.java b/hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/lazy/LazyOneToManyWithEqualsImplementationTest.java
new file mode 100644
index 0000000000..68dc27fca5
--- /dev/null
+++ b/hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/lazy/LazyOneToManyWithEqualsImplementationTest.java
@@ -0,0 +1,128 @@
+/*
+ * 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.lazy;
+
+import org.hibernate.annotations.LazyToOne;
+import org.hibernate.annotations.LazyToOneOption;
+import org.hibernate.jpa.test.BaseEntityManagerFunctionalTestCase;
+import org.hibernate.testing.TestForIssue;
+import org.hibernate.testing.bytecode.enhancement.BytecodeEnhancerRunner;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import javax.persistence.Basic;
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.ManyToOne;
+import javax.persistence.OneToMany;
+
+import java.util.HashSet;
+import java.util.Objects;
+import java.util.Set;
+
+import static org.hibernate.testing.transaction.TransactionUtil.doInJPA;
+import static org.junit.Assert.assertEquals;
+
+@TestForIssue(jiraKey = "HHH-13380")
+@RunWith( BytecodeEnhancerRunner.class )
+public class LazyOneToManyWithEqualsImplementationTest
+        extends BaseEntityManagerFunctionalTestCase {
+
+    private Long personId;
+
+    @Override
+    protected Class<?>[] getAnnotatedClasses() {
+        return new Class<?>[] { Person.class, Course.class };
+    }
+
+    @Before
+    public void setUp() {
+        doInJPA( this::entityManagerFactory, entityManager -> {
+            Person p = new Person();
+            entityManager.persist(p);
+            personId = p.getId();
+
+            Course c1 = new Course( "First Course", p );
+            p.getCourses().add( c1 );
+            entityManager.persist( c1 );
+
+            Course c2 = new Course("Second Course", p );
+            p.getCourses().add( c2 );
+            entityManager.persist( c2 );
+        });
+    }
+
+
+    @Test
+    public void testRetrievalOfOneToMany() {
+        doInJPA(this::entityManagerFactory, entityManager -> {
+            Person p = entityManager.find( Person.class, personId );
+
+            Set<Course> courses = p.getCourses();
+            assertEquals( courses.size(), 2 );
+        });
+    }
+
+    @Entity(name = "Person")
+    public static class Person {
+
+        @Id
+        @GeneratedValue()
+        private Long id;
+        public Long getId() {
+            return id;
+        }
+
+        @OneToMany(mappedBy="person", fetch = FetchType.LAZY)
+        private Set<Course> courses = new HashSet<>();
+        public Set<Course> getCourses() { return courses; }
+
+    }
+
+    @Entity(name = "Course")
+    public static class Course {
+
+        @Id
+        @GeneratedValue()
+        private Long id;
+        public Long getId() { return id; }
+
+        @Basic
+        private String title;
+        public String getTitle() { return title; }
+
+        @ManyToOne(fetch = FetchType.LAZY)
+        @LazyToOne(LazyToOneOption.NO_PROXY)
+        private Person person;
+        public Person getPerson() { return person; }
+
+        protected Course() {}
+        public Course(String title, Person person) {
+            this.title = title;
+            this.person = person;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if ( this == o ) return true;
+            if ( o == null || getClass() != o.getClass() ) return false;
+            Course course = (Course) o;
+            return title.equals( course.title ) &&
+                    person.equals( course.person );
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash( title, person );
+        }
+    }
+
+}