diff --git a/doctrine-mapping.xsd b/doctrine-mapping.xsd
index 95fd62425..1f3f1476d 100644
--- a/doctrine-mapping.xsd
+++ b/doctrine-mapping.xsd
@@ -210,28 +210,39 @@
     <xs:attribute name="schema" type="xs:NMTOKEN" />
   </xs:complexType>
 
+  <xs:complexType name="order-by">
+      <xs:sequence>
+          <xs:element name="order-by-field" type="orm:order-by-field" minOccurs="1" maxOccurs="unbounded" />
+      </xs:sequence>
+  </xs:complexType>
+
+  <xs:complexType name="order-by-field">
+      <xs:attribute name="field" type="XS:NMTOKEN" use="required" />
+      <xs:attribute name="direction" type="XS:NMTOKEN" default="ASC" />
+  </xs:complexType>
+
   <xs:complexType name="many-to-many">
     <xs:sequence>
       <xs:element name="cascade" type="orm:cascade-type" minOccurs="0" />
       <xs:element name="join-table" type="orm:join-table" minOccurs="0" />
+      <xs:element name="order-by" type="orm:order-by" minOccurs="0" />
     </xs:sequence>
     <xs:attribute name="target-entity" type="xs:NMTOKEN" use="required" />
     <xs:attribute name="field" type="xs:NMTOKEN" use="required" />
     <xs:attribute name="mapped-by" type="xs:NMTOKEN" />
     <xs:attribute name="fetch" type="orm:fetch-type" default="LAZY" />
-    <xs:attribute name="order-by" type="xs:string" />
   </xs:complexType>
 
   <xs:complexType name="one-to-many">
     <xs:sequence>
       <xs:element name="cascade" type="orm:cascade-type" minOccurs="0" />
+      <xs:element name="order-by" type="orm:order-by" minOccurs="0" />
     </xs:sequence>
     <xs:attribute name="target-entity" type="xs:NMTOKEN" use="required" />
     <xs:attribute name="mapped-by" type="xs:NMTOKEN" />
     <xs:attribute name="field" type="xs:NMTOKEN" use="required" />
     <xs:attribute name="orphan-removal" type="xs:boolean" default="false" />
     <xs:attribute name="fetch" type="orm:fetch-type" default="LAZY" />
-    <xs:attribute name="order-by" type="xs:string" />
   </xs:complexType>
   
   <xs:complexType name="many-to-one">