diff --git a/jpa/eclipselink.jpa.testapps/jpa.test.persistence32/src/test/java/org/eclipse/persistence/testing/tests/jpa/persistence32/UnionCriteriaQueryTest.java b/jpa/eclipselink.jpa.testapps/jpa.test.persistence32/src/test/java/org/eclipse/persistence/testing/tests/jpa/persistence32/UnionCriteriaQueryTest.java
index 4ec968f5856..96bd487c21c 100644
--- a/jpa/eclipselink.jpa.testapps/jpa.test.persistence32/src/test/java/org/eclipse/persistence/testing/tests/jpa/persistence32/UnionCriteriaQueryTest.java
+++ b/jpa/eclipselink.jpa.testapps/jpa.test.persistence32/src/test/java/org/eclipse/persistence/testing/tests/jpa/persistence32/UnionCriteriaQueryTest.java
@@ -59,6 +59,7 @@ public static Test suite() {
                 new UnionCriteriaQueryTest("testExceptAllWithNoSelection"),
                 new UnionCriteriaQueryTest("testUnionWithEntityParameterInSelection"),
                 new UnionCriteriaQueryTest("testUnionWithMultiselectEntityParametersInSelection"),
+                new UnionCriteriaQueryTest("testUnionWithMultiselectEntityParametersInSelectionResultTypePartial"),
                 new UnionCriteriaQueryTest("testUnionWithMultiselectEntityInSelection")
         );
     }
@@ -415,8 +416,37 @@ public void testUnionWithMultiselectEntityParametersInSelection() {
         }
     }
 
-    // TODO testUnionWithMultiselectEntityParametersInSelection without supporting constructor
-    // to validate ResultType.PARTIAL with compound query
+    // Selects partial content of existing Trainer constructor prototype
+    // This shall trigger compound query builder with ResultType.PARTIAL.
+    @SuppressWarnings("deprecation")
+    public void testUnionWithMultiselectEntityParametersInSelectionResultTypePartial() {
+        try (EntityManager em = emf.createEntityManager()) {
+            EntityTransaction et = em.getTransaction();
+            try {
+                et.begin();
+                CriteriaBuilder cb = em.getCriteriaBuilder();
+
+                CriteriaQuery<Trainer> q1 = cb.createQuery(Trainer.class);
+                Root<Trainer> root1 = q1.from(Trainer.class);
+                q1.multiselect(root1.get("id"), root1.get("name"));
+                q1.where(cb.equal(root1.get("name"), cb.parameter(String.class, "name1")));
+
+                CriteriaQuery<Trainer> q2 = cb.createQuery(Trainer.class);
+                Root<Trainer> root2 = q2.from(Trainer.class);
+                q2.multiselect(root2.get("id"), root2.get("name"));
+                q2.where(cb.equal(root2.get("name"), cb.parameter(String.class, "name2")));
+
+                TypedQuery<Trainer> query = em.createQuery(cb.union(q1, q2));
+                query.setParameter("name1", TRAINERS[1].getName());
+                query.setParameter("name2", TRAINERS[2].getName());
+                List<Trainer> trainers = query.getResultList();
+                assertEquals(2, trainers.size());
+            } catch (Exception e) {
+                et.rollback();
+                throw e;
+            }
+        }
+    }
 
     public void testUnionWithMultiselectEntityInSelection() {
         try (EntityManager em = emf.createEntityManager()) {
diff --git a/jpa/org.eclipse.persistence.jpa/src/main/java/org/eclipse/persistence/internal/jpa/querydef/CriteriaQueryImpl.java b/jpa/org.eclipse.persistence.jpa/src/main/java/org/eclipse/persistence/internal/jpa/querydef/CriteriaQueryImpl.java
index 462fe1e7e86..338ed3c6fb2 100644
--- a/jpa/org.eclipse.persistence.jpa/src/main/java/org/eclipse/persistence/internal/jpa/querydef/CriteriaQueryImpl.java
+++ b/jpa/org.eclipse.persistence.jpa/src/main/java/org/eclipse/persistence/internal/jpa/querydef/CriteriaQueryImpl.java
@@ -498,20 +498,21 @@ protected ReadAllQuery createCompoundQuery(boolean toReportQuery) {
 
         if (this.queryResult.equals(ResultType.PARTIAL)) {
             ReadAllQuery raq;
-            // TODO: allow force of ReportQuery creation for usage in UNION
-            // TODO: In progress, code is not working and tested !!!
-            // See testUnionWithMultiselectEntityParametersInSelection TODO in UnionCriteriaQueryTest
+            @SuppressWarnings("unchecked")
+            List<SelectionImpl<?>> selectionItems = (List<SelectionImpl<?>>) (List<?>) this.selection.getCompoundSelectionItems();
             if (toReportQuery) {
-                //raq = createReportQuery(this.queryType);
-                raq = createReportQueryWithItem(this.queryType);
+                raq = createReportQuery(this.queryType);
+                for (SelectionImpl<?> nested : selectionItems) {
+                    ((ReportQuery) raq).addAttribute(nested.getAlias(), nested.getCurrentNode(), nested.getJavaType());
+                }
             } else {
                 raq = new ReadAllQuery(this.queryType);
             }
-            // TODO: double check whether this may be avoided
+            // Partial object queries are not allowed to maintain the cache or be edited. Requires dontMaintainCache().
+            // See hasPartialAttributeExpressions() in ObjectLevelReadQuery#prepareQuery()
             raq.dontMaintainCache();
-            // TODO: ROOTS?
-            for (Selection selection : this.selection.getCompoundSelectionItems()) {
-                raq.addPartialAttribute(((SelectionImpl) selection).currentNode);
+            for (SelectionImpl<?> selection : selectionItems) {
+                raq.addPartialAttribute((selection).currentNode);
             }
             raq.setExpressionBuilder(((InternalSelection) this.selection.getCompoundSelectionItems().get(0)).getCurrentNode().getBuilder());
             query = raq;