diff --git a/hibernate-entitymanager/src/main/java/org/hibernate/jpa/criteria/CriteriaQueryImpl.java b/hibernate-entitymanager/src/main/java/org/hibernate/jpa/criteria/CriteriaQueryImpl.java
index 9c8cf6a992..143ec4521f 100755
--- a/hibernate-entitymanager/src/main/java/org/hibernate/jpa/criteria/CriteriaQueryImpl.java
+++ b/hibernate-entitymanager/src/main/java/org/hibernate/jpa/criteria/CriteriaQueryImpl.java
@@ -26,6 +26,7 @@ package org.hibernate.jpa.criteria;
 import java.io.Serializable;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -43,6 +44,8 @@ import javax.persistence.metamodel.EntityType;
 
 import org.jboss.logging.Logger;
 
+import org.hibernate.internal.util.StringHelper;
+import org.hibernate.internal.util.collections.CollectionHelper;
 import org.hibernate.jpa.internal.QueryImpl;
 import org.hibernate.jpa.criteria.compile.CompilableCriteria;
 import org.hibernate.jpa.criteria.compile.CriteriaInterpretation;
@@ -76,9 +79,7 @@ public class CriteriaQueryImpl<T> extends AbstractNode implements CriteriaQuery<
 		this.queryStructure = new QueryStructure<T>( this, criteriaBuilder );
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public Class<T> getResultType() {
 		return returnType;
 	}
@@ -86,24 +87,18 @@ public class CriteriaQueryImpl<T> extends AbstractNode implements CriteriaQuery<
 
 	// SELECTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public CriteriaQuery<T> distinct(boolean applyDistinction) {
 		queryStructure.setDistinct( applyDistinction );
 		return this;
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public boolean isDistinct() {
 		return queryStructure.isDistinct();
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	@SuppressWarnings({ "unchecked" })
 	public Selection<T> getSelection() {
 		return ( Selection<T> ) queryStructure.getSelection();
@@ -113,29 +108,25 @@ public class CriteriaQueryImpl<T> extends AbstractNode implements CriteriaQuery<
 		queryStructure.setSelection( selection );
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public CriteriaQuery<T> select(Selection<? extends T> selection) {
 		applySelection( selection );
 		return this;
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	@SuppressWarnings({ "unchecked" })
 	public CriteriaQuery<T> multiselect(Selection<?>... selections) {
 		return multiselect( Arrays.asList( selections ) );
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	@SuppressWarnings({ "unchecked" })
 	public CriteriaQuery<T> multiselect(List<Selection<?>> selections) {
 		final Selection<? extends T> selection;
 
+		validateSelections( selections );
+
 		if ( Tuple.class.isAssignableFrom( getResultType() ) ) {
 			selection = ( Selection<? extends T> ) criteriaBuilder().tuple( selections );
 		}
@@ -168,26 +159,34 @@ public class CriteriaQueryImpl<T> extends AbstractNode implements CriteriaQuery<
 		return this;
 	}
 
+	private void validateSelections(List<Selection<?>> selections) {
+		// handle the requirement that we validate that the incoming selections do not contain
+		// duplicate aliases.
+		final HashSet<String> aliases = new HashSet<String>( CollectionHelper.determineProperSizing( selections.size() ) );
+		for ( Selection<?> selection : selections ) {
+			if ( StringHelper.isNotEmpty( selection.getAlias() ) ) {
+				boolean added = aliases.add( selection.getAlias() );
+				if ( ! added ) {
+					throw new IllegalArgumentException( "Multi-select expressions defined duplicate alias : " + selection.getAlias() );
+				}
+			}
+		}
+	}
+
 
 	// ROOTS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public Set<Root<?>> getRoots() {
 		return queryStructure.getRoots();
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public <X> Root<X> from(EntityType<X> entityType) {
 		return queryStructure.from( entityType );
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public <X> Root<X> from(Class<X> entityClass) {
 		return queryStructure.from( entityClass );
 	}
@@ -195,24 +194,18 @@ public class CriteriaQueryImpl<T> extends AbstractNode implements CriteriaQuery<
 
 	// RESTRICTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public Predicate getRestriction() {
 		return queryStructure.getRestriction();
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public CriteriaQuery<T> where(Expression<Boolean> expression) {
 		queryStructure.setRestriction( criteriaBuilder().wrap( expression ) );
 		return this;
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public CriteriaQuery<T> where(Predicate... predicates) {
 		// TODO : assuming this should be a conjuntion, but the spec does not say specifically...
 		queryStructure.setRestriction( criteriaBuilder().and( predicates ) );
@@ -222,44 +215,35 @@ public class CriteriaQueryImpl<T> extends AbstractNode implements CriteriaQuery<
 
 	// GROUPING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public List<Expression<?>> getGroupList() {
 		return queryStructure.getGroupings();
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public CriteriaQuery<T> groupBy(Expression<?>... groupings) {
 		queryStructure.setGroupings( groupings );
 		return this;
 	}
 
+	@Override
 	public CriteriaQuery<T> groupBy(List<Expression<?>> groupings) {
 		queryStructure.setGroupings( groupings );
 		return this;
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public Predicate getGroupRestriction() {
 		return queryStructure.getHaving();
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public CriteriaQuery<T> having(Expression<Boolean> expression) {
 		queryStructure.setHaving( criteriaBuilder().wrap( expression ) );
 		return this;
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public CriteriaQuery<T> having(Predicate... predicates) {
 		queryStructure.setHaving( criteriaBuilder().and( predicates ) );
 		return this;
@@ -268,16 +252,12 @@ public class CriteriaQueryImpl<T> extends AbstractNode implements CriteriaQuery<
 
 	// ORDERING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public List<Order> getOrderList() {
 		return orderSpecs;
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public CriteriaQuery<T> orderBy(Order... orders) {
 		if ( orders != null && orders.length > 0 ) {
 			orderSpecs = Arrays.asList( orders );
@@ -288,28 +268,23 @@ public class CriteriaQueryImpl<T> extends AbstractNode implements CriteriaQuery<
 		return this;
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public CriteriaQuery<T> orderBy(List<Order> orders) {
 		orderSpecs = orders;
 		return this;
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public Set<ParameterExpression<?>> getParameters() {
 		return queryStructure.getParameters();
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
+	@Override
 	public <U> Subquery<U> subquery(Class<U> subqueryType) {
 		return queryStructure.subquery( subqueryType );
 	}
 
+	@Override
 	public void validate() {
 		// getRoots() is explicitly supposed to return empty if none defined, no need to check for null
 		if ( getRoots().isEmpty() ) {