diff --git a/querydsl-jpa/pom.xml b/querydsl-jpa/pom.xml
index 8006c0f09..f2e3a1237 100644
--- a/querydsl-jpa/pom.xml
+++ b/querydsl-jpa/pom.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd" xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <modelVersion>4.0.0</modelVersion>
 
@@ -16,8 +16,8 @@
   <packaging>jar</packaging>
   
   <properties>
-    <hibernate.version>4.2.0.Final</hibernate.version>
-    <hibernate.validator.version>4.3.0.Final</hibernate.validator.version>
+    <hibernate.version>4.3.5.Final</hibernate.version>
+    <hibernate.validator.version>4.3.1.Final</hibernate.validator.version>
     <eclipselink.version>2.5.1</eclipselink.version>
   </properties>
   
@@ -59,7 +59,7 @@
  
     <dependency>
       <groupId>org.hibernate.javax.persistence</groupId>
-      <artifactId>hibernate-jpa-2.0-api</artifactId>
+      <artifactId>hibernate-jpa-2.1-api</artifactId>
       <version>1.0.0.Final</version>
       <scope>provided</scope>
     </dependency>
@@ -342,4 +342,4 @@
     </plugins>
   </build>
 
-</project>
+</project>
diff --git a/querydsl-jpa/src/main/java/com/mysema/query/jpa/JPQLOps.java b/querydsl-jpa/src/main/java/com/mysema/query/jpa/JPQLOps.java
index e96da04a9..16d222879 100644
--- a/querydsl-jpa/src/main/java/com/mysema/query/jpa/JPQLOps.java
+++ b/querydsl-jpa/src/main/java/com/mysema/query/jpa/JPQLOps.java
@@ -24,6 +24,8 @@ public final class JPQLOps {
 
     private static final String NS = JPQLOps.class.getName();
 
+    public static final Operator<Object> TREAT = new OperatorImpl<Object>(NS, "TREAT");
+
     public static final Operator<Integer> INDEX = new OperatorImpl<Integer>(NS, "INDEX");
 
     public static final Operator<String> TYPE = new OperatorImpl<String>(NS, "TYPE");
diff --git a/querydsl-jpa/src/main/java/com/mysema/query/jpa/JPQLSerializer.java b/querydsl-jpa/src/main/java/com/mysema/query/jpa/JPQLSerializer.java
index 0d2cc5790..d4eda0958 100644
--- a/querydsl-jpa/src/main/java/com/mysema/query/jpa/JPQLSerializer.java
+++ b/querydsl-jpa/src/main/java/com/mysema/query/jpa/JPQLSerializer.java
@@ -13,50 +13,22 @@
  */
 package com.mysema.query.jpa;
 
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
-import javax.annotation.Nullable;
-import javax.persistence.DiscriminatorValue;
-import javax.persistence.Entity;
-import javax.persistence.EntityManager;
-import javax.persistence.EnumType;
-import javax.persistence.Enumerated;
-import javax.persistence.PersistenceUnitUtil;
-import javax.persistence.metamodel.EntityType;
-import javax.persistence.metamodel.Metamodel;
-import javax.persistence.metamodel.SingularAttribute;
-
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.mysema.query.JoinExpression;
 import com.mysema.query.JoinType;
 import com.mysema.query.QueryMetadata;
 import com.mysema.query.support.SerializerBase;
-import com.mysema.query.types.Constant;
-import com.mysema.query.types.ConstantImpl;
-import com.mysema.query.types.EntityPath;
-import com.mysema.query.types.Expression;
-import com.mysema.query.types.ExpressionUtils;
-import com.mysema.query.types.FactoryExpression;
-import com.mysema.query.types.Operation;
-import com.mysema.query.types.Operator;
-import com.mysema.query.types.Ops;
-import com.mysema.query.types.Order;
-import com.mysema.query.types.OrderSpecifier;
-import com.mysema.query.types.ParamExpression;
-import com.mysema.query.types.Path;
-import com.mysema.query.types.PathImpl;
-import com.mysema.query.types.PathType;
-import com.mysema.query.types.Predicate;
-import com.mysema.query.types.SubQueryExpression;
+import com.mysema.query.types.*;
 import com.mysema.util.MathUtils;
 
+import javax.annotation.Nullable;
+import javax.persistence.*;
+import javax.persistence.metamodel.EntityType;
+import javax.persistence.metamodel.Metamodel;
+import javax.persistence.metamodel.SingularAttribute;
+import java.util.*;
+
 /**
  * JPQLSerializer serializes Querydsl expressions into JPQL syntax.
  *
@@ -127,25 +99,54 @@ public class JPQLSerializer extends SerializerBase<JPQLSerializer> {
         this.entityManager = em;
     }
 
+    private String getEntityName(Class<?> clazz) {
+        final Entity entityAnnotation = clazz.getAnnotation(Entity.class);
+        if (entityAnnotation != null && entityAnnotation.name().length() > 0) {
+            return entityAnnotation.name();
+        } else if (clazz.getPackage() != null) {
+            String pn = clazz.getPackage().getName();
+            return clazz.getName().substring(pn.length() + 1);
+        } else {
+            return clazz.getName();
+        }
+    }
+
     private void handleJoinTarget(JoinExpression je) {
         // type specifier
         if (je.getTarget() instanceof EntityPath<?>) {
             final EntityPath<?> pe = (EntityPath<?>) je.getTarget();
             if (pe.getMetadata().isRoot()) {
-                final Entity entityAnnotation = pe.getAnnotatedElement().getAnnotation(Entity.class);
-                if (entityAnnotation != null && entityAnnotation.name().length() > 0) {
-                    append(entityAnnotation.name());
-                } else if (pe.getType().getPackage() != null) {
-                    final String pn = pe.getType().getPackage().getName();
-                    final String typeName = pe.getType().getName().substring(pn.length() + 1);
-                    append(typeName);
-                } else {
-                    append(pe.getType().getName());
-                }
+                append(getEntityName(pe.getType()));
                 append(" ");
             }
+            handle(je.getTarget());
+        } else if (je.getTarget() instanceof Operation) {
+            Operation<?> op = (Operation)je.getTarget();
+            if (op.getOperator() == Ops.ALIAS) {
+                boolean treat = false;
+                if (Collection.class.isAssignableFrom(op.getArg(0).getType())) {
+                    if (op.getArg(0) instanceof CollectionExpression) {
+                        Class<?> par = ((CollectionExpression)op.getArg(0)).getParameter(0);
+                        treat = !par.equals(op.getArg(1).getType());
+                    }
+                } else if (Map.class.isAssignableFrom(op.getArg(0).getType())) {
+                    if (op.getArg(0) instanceof MapExpression) {
+                        Class<?> par = ((MapExpression)op.getArg(0)).getParameter(1);
+                        treat = !par.equals(op.getArg(1).getType());
+                    }
+                } else {
+                    treat = !op.getArg(0).getType().equals(op.getArg(1).getType());
+                }
+                if (treat) {
+                    Expression<?> entityName = ConstantImpl.create(getEntityName(op.getArg(1).getType()));
+                    Expression<?> t = OperationImpl.create(op.getType(), JPQLOps.TREAT, op.getArg(0), entityName);
+                    op = OperationImpl.create(op.getType(), Ops.ALIAS, t, op.getArg(1));
+                }
+            }
+            handle(op);
+        } else {
+            handle(je.getTarget());
         }
-        handle(je.getTarget());
     }
 
     public void serialize(QueryMetadata metadata, boolean forCountRow, @Nullable String projection) {
diff --git a/querydsl-jpa/src/main/java/com/mysema/query/jpa/JPQLTemplates.java b/querydsl-jpa/src/main/java/com/mysema/query/jpa/JPQLTemplates.java
index afaa5775e..c4dcf8bf8 100644
--- a/querydsl-jpa/src/main/java/com/mysema/query/jpa/JPQLTemplates.java
+++ b/querydsl-jpa/src/main/java/com/mysema/query/jpa/JPQLTemplates.java
@@ -13,13 +13,13 @@
  */
 package com.mysema.query.jpa;
 
-import javax.annotation.Nullable;
-
 import com.mysema.query.types.Operator;
 import com.mysema.query.types.Ops;
 import com.mysema.query.types.PathType;
 import com.mysema.query.types.Templates;
 
+import javax.annotation.Nullable;
+
 /**
  * JPQLTemplates extends {@link Templates} to provide operator patterns for JPQL
  * serialization
@@ -130,8 +130,8 @@ public class JPQLTemplates extends Templates {
 
         add(Ops.INSTANCE_OF, "type({0}) = {1}");
         add(JPQLOps.TYPE, "type({0})");
-
         add(JPQLOps.INDEX, "index({0})");
+        add(JPQLOps.TREAT, "treat({0} as {1s})");
 
         //CHECKSTYLE:ON
     }
diff --git a/querydsl-jpa/src/test/java/com/mysema/query/AbstractJPATest.java b/querydsl-jpa/src/test/java/com/mysema/query/AbstractJPATest.java
index 38a3bed03..3b3934cf4 100644
--- a/querydsl-jpa/src/test/java/com/mysema/query/AbstractJPATest.java
+++ b/querydsl-jpa/src/test/java/com/mysema/query/AbstractJPATest.java
@@ -13,38 +13,8 @@
  */
 package com.mysema.query;
 
-import static com.mysema.query.Target.DERBY;
-import static com.mysema.query.Target.HSQLDB;
-import static com.mysema.query.Target.MYSQL;
-import static com.mysema.query.Target.ORACLE;
-import static com.mysema.query.Target.TERADATA;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
-
-import java.math.BigDecimal;
-import java.math.BigInteger;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Calendar;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Date;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.UUID;
-
-import org.junit.Before;
-import org.junit.Ignore;
-import org.junit.Test;
-
 import antlr.RecognitionException;
 import antlr.TokenStreamException;
-
 import com.google.common.collect.Lists;
 import com.mysema.commons.lang.Pair;
 import com.mysema.query.group.Group;
@@ -53,67 +23,29 @@ import com.mysema.query.group.QPair;
 import com.mysema.query.jpa.JPAExpressions;
 import com.mysema.query.jpa.JPASubQuery;
 import com.mysema.query.jpa.JPQLQuery;
-import com.mysema.query.jpa.domain.Animal;
-import com.mysema.query.jpa.domain.Author;
-import com.mysema.query.jpa.domain.Book;
-import com.mysema.query.jpa.domain.Cat;
-import com.mysema.query.jpa.domain.Color;
-import com.mysema.query.jpa.domain.Company;
+import com.mysema.query.jpa.domain.*;
 import com.mysema.query.jpa.domain.Company.Rating;
-import com.mysema.query.jpa.domain.DomesticCat;
-import com.mysema.query.jpa.domain.DoubleProjection;
-import com.mysema.query.jpa.domain.Employee;
-import com.mysema.query.jpa.domain.Entity1;
-import com.mysema.query.jpa.domain.Entity2;
-import com.mysema.query.jpa.domain.FloatProjection;
-import com.mysema.query.jpa.domain.Foo;
-import com.mysema.query.jpa.domain.JobFunction;
-import com.mysema.query.jpa.domain.Numeric;
-import com.mysema.query.jpa.domain.QAnimal;
-import com.mysema.query.jpa.domain.QAuthor;
-import com.mysema.query.jpa.domain.QBook;
-import com.mysema.query.jpa.domain.QCat;
-import com.mysema.query.jpa.domain.QCompany;
-import com.mysema.query.jpa.domain.QDoubleProjection;
-import com.mysema.query.jpa.domain.QEmployee;
-import com.mysema.query.jpa.domain.QEntity1;
-import com.mysema.query.jpa.domain.QFloatProjection;
-import com.mysema.query.jpa.domain.QFoo;
-import com.mysema.query.jpa.domain.QHuman;
-import com.mysema.query.jpa.domain.QMammal;
-import com.mysema.query.jpa.domain.QNumeric;
-import com.mysema.query.jpa.domain.QShow;
-import com.mysema.query.jpa.domain.QSimpleTypes;
-import com.mysema.query.jpa.domain.QUser;
-import com.mysema.query.jpa.domain.QWorld;
-import com.mysema.query.jpa.domain.Show;
 import com.mysema.query.jpa.domain4.QBookMark;
 import com.mysema.query.jpa.domain4.QBookVersion;
 import com.mysema.query.jpa.hibernate.HibernateSubQuery;
 import com.mysema.query.support.Expressions;
-import com.mysema.query.types.ArrayConstructorExpression;
-import com.mysema.query.types.Concatenation;
-import com.mysema.query.types.ConstructorExpression;
-import com.mysema.query.types.EntityPath;
-import com.mysema.query.types.Expression;
-import com.mysema.query.types.ExpressionUtils;
-import com.mysema.query.types.ParamNotSetException;
-import com.mysema.query.types.Path;
-import com.mysema.query.types.Predicate;
-import com.mysema.query.types.Projections;
-import com.mysema.query.types.QTuple;
-import com.mysema.query.types.expr.BooleanExpression;
-import com.mysema.query.types.expr.ListExpression;
-import com.mysema.query.types.expr.Param;
-import com.mysema.query.types.expr.SimpleExpression;
-import com.mysema.query.types.expr.StringExpression;
-import com.mysema.query.types.path.EnumPath;
-import com.mysema.query.types.path.ListPath;
-import com.mysema.query.types.path.NumberPath;
-import com.mysema.query.types.path.SimplePath;
-import com.mysema.query.types.path.StringPath;
+import com.mysema.query.types.*;
+import com.mysema.query.types.expr.*;
+import com.mysema.query.types.path.*;
 import com.mysema.testutil.ExcludeIn;
 import com.mysema.testutil.IncludeIn;
+import org.junit.Before;
+import org.junit.Ignore;
+import org.junit.Test;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.*;
+import java.util.Calendar;
+import java.util.Map.Entry;
+
+import static com.mysema.query.Target.*;
+import static org.junit.Assert.*;
 
 /**
  * @author tiwe
@@ -441,7 +373,7 @@ public abstract class AbstractJPATest {
         }
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test(expected=ClassCastException.class)
     @NoEclipseLink
     @NoBatooJPA
     public void Constant_Hibernate() {
@@ -1483,6 +1415,17 @@ public abstract class AbstractJPATest {
         }
     }
 
+    @Test
+    @NoBatooJPA
+    @NoEclipseLink
+    public void Treat() {
+        QDomesticCat domesticCat = QDomesticCat.domesticCat;
+        query().from(cat)
+               .innerJoin(cat.mate, domesticCat._super)
+               .where(domesticCat.name.eq("Bobby"))
+               .count();
+    }
+
     @Test
     @Ignore
     public void Type() {
@@ -1490,7 +1433,6 @@ public abstract class AbstractJPATest {
                 query().from(animal).orderBy(animal.id.asc()).list(JPAExpressions.type(animal)));
     }
 
-
     @Test
     @NoOpenJPA
     public void Type_Order() {
diff --git a/querydsl-jpa/src/test/java/com/mysema/query/JPABase.java b/querydsl-jpa/src/test/java/com/mysema/query/JPABase.java
index 933fb1a30..84786d2e8 100644
--- a/querydsl-jpa/src/test/java/com/mysema/query/JPABase.java
+++ b/querydsl-jpa/src/test/java/com/mysema/query/JPABase.java
@@ -13,39 +13,30 @@
  */
 package com.mysema.query;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertTrue;
-
-import java.sql.Connection;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-import javax.persistence.EntityManager;
-import javax.persistence.FlushModeType;
-import javax.persistence.LockModeType;
-
-import org.junit.Ignore;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.MethodRule;
-import org.junit.runner.RunWith;
-
 import com.mysema.commons.lang.CloseableIterator;
 import com.mysema.query.jpa.JPASubQuery;
-import com.mysema.query.jpa.domain.Cat;
-import com.mysema.query.jpa.domain.QCat;
-import com.mysema.query.jpa.domain.QCatSummary;
-import com.mysema.query.jpa.domain.QChild;
-import com.mysema.query.jpa.domain.QParent;
+import com.mysema.query.jpa.domain.*;
 import com.mysema.query.jpa.impl.JPADeleteClause;
 import com.mysema.query.jpa.impl.JPAQuery;
 import com.mysema.query.types.EntityPath;
 import com.mysema.query.types.expr.BooleanExpression;
 import com.mysema.testutil.ExcludeIn;
 import com.mysema.testutil.JPATestRunner;
+import org.junit.Ignore;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.MethodRule;
+import org.junit.runner.RunWith;
+
+import javax.persistence.EntityManager;
+import javax.persistence.FlushModeType;
+import javax.persistence.LockModeType;
+import java.sql.Connection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static org.junit.Assert.*;
 
 /**
  * @author tiwe
@@ -88,7 +79,9 @@ public class JPABase extends AbstractJPATest {
     }
 
     @Test
-    @NoEclipseLink @NoOpenJPA
+    @NoEclipseLink
+    @NoOpenJPA
+    @NoHibernate
     public void Connection_Access() {
         assertNotNull(query().from(cat).createQuery(cat).unwrap(Connection.class));
     }
diff --git a/querydsl-jpa/src/test/java/com/mysema/query/jpa/JPQLSerializerTest.java b/querydsl-jpa/src/test/java/com/mysema/query/jpa/JPQLSerializerTest.java
index 6e14eebee..d87df061e 100644
--- a/querydsl-jpa/src/test/java/com/mysema/query/jpa/JPQLSerializerTest.java
+++ b/querydsl-jpa/src/test/java/com/mysema/query/jpa/JPQLSerializerTest.java
@@ -13,25 +13,26 @@
  */
 package com.mysema.query.jpa;
 
-import static org.junit.Assert.assertEquals;
-
-import java.util.Arrays;
-
-import org.junit.Test;
-
 import com.mysema.query.DefaultQueryMetadata;
 import com.mysema.query.JoinType;
 import com.mysema.query.QueryMetadata;
 import com.mysema.query.domain.QCat;
 import com.mysema.query.jpa.domain.Location;
+import com.mysema.query.jpa.domain.QDomesticCat;
 import com.mysema.query.jpa.domain.QEmployee;
 import com.mysema.query.support.Expressions;
 import com.mysema.query.types.EntityPath;
 import com.mysema.query.types.Expression;
+import com.mysema.query.types.Path;
 import com.mysema.query.types.Predicate;
 import com.mysema.query.types.path.EntityPathBase;
 import com.mysema.query.types.path.NumberPath;
 import com.mysema.query.types.path.StringPath;
+import org.junit.Test;
+
+import java.util.Arrays;
+
+import static org.junit.Assert.assertEquals;
 
 public class JPQLSerializerTest {
 
@@ -196,4 +197,18 @@ public class JPQLSerializerTest {
                      "from Cat cat\n" +
                      "order by cat.name asc nulls last", serializer.toString());
     }
+
+    @Test
+    public void Treat() {
+        QCat cat = QCat.cat;
+        JPQLSerializer serializer = new JPQLSerializer(HQLTemplates.DEFAULT);
+        QueryMetadata md = new DefaultQueryMetadata();
+        md.addJoin(JoinType.DEFAULT, cat);
+        md.addJoin(JoinType.JOIN, cat.mate.as((Path)QDomesticCat.domesticCat));
+        md.addProjection(QDomesticCat.domesticCat);
+        serializer.serialize(md, false, null);
+        assertEquals("select domesticCat\n" +
+                     "from Cat cat\n" +
+                     "  inner join treat(cat.mate as DomesticCat) as domesticCat", serializer.toString());
+    }
 }
diff --git a/querydsl-jpa/src/test/java/com/mysema/testutil/HibernateTestRunner.java b/querydsl-jpa/src/test/java/com/mysema/testutil/HibernateTestRunner.java
index 408c2ad40..699941473 100644
--- a/querydsl-jpa/src/test/java/com/mysema/testutil/HibernateTestRunner.java
+++ b/querydsl-jpa/src/test/java/com/mysema/testutil/HibernateTestRunner.java
@@ -13,13 +13,8 @@
  */
 package com.mysema.testutil;
 
-import java.io.InputStream;
-import java.lang.reflect.Method;
-import java.sql.DriverManager;
-import java.sql.SQLException;
-import java.util.List;
-import java.util.Properties;
-
+import com.mysema.query.Mode;
+import com.mysema.query.jpa.domain.Domain;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.hibernate.cfg.Configuration;
@@ -34,8 +29,12 @@ import org.junit.runners.model.FrameworkMethod;
 import org.junit.runners.model.InitializationError;
 import org.junit.runners.model.Statement;
 
-import com.mysema.query.Mode;
-import com.mysema.query.jpa.domain.Domain;
+import java.io.InputStream;
+import java.lang.reflect.Method;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.util.List;
+import java.util.Properties;
 
 /**
  * @author tiwe
@@ -109,7 +108,7 @@ public class HibernateTestRunner extends BlockJUnit4ClassRunner {
         props.load(is);
         ServiceRegistry serviceRegistry = new ServiceRegistryBuilder()
             .applySettings(props)
-            .buildServiceRegistry();
+            .build();
         cfg.setProperties(props);
         sessionFactory = cfg.buildSessionFactory(serviceRegistry);
         session = sessionFactory.openSession();