diff --git a/source/wsdl/cml.xsd b/source/wsdl/cml.xsd
index 1876a335c1..0677acf398 100644
--- a/source/wsdl/cml.xsd
+++ b/source/wsdl/cml.xsd
@@ -21,7 +21,7 @@
 					    <xsd:element name="id" type="xsd:string" maxOccurs="1" minOccurs="0"></xsd:element>
 						<xsd:element name="parent" type="cms:ParentReference" maxOccurs="1" minOccurs="0" nillable="true"></xsd:element>
 						<xsd:element name="parent_id" type="xsd:string" maxOccurs="1" minOccurs="0" nillable="true"></xsd:element>
-				        <xsd:group ref="cms:ChildAssociation" maxOccurs="1" minOccurs="0" nillable="true"></xsd:group>
+				        <xsd:group ref="cms:ChildAssociation" maxOccurs="1" minOccurs="0"></xsd:group>
 						<xsd:element name="type" type="cms:Name" maxOccurs="1" minOccurs="0"></xsd:element>
 						<xsd:element name="property" type="cms:NamedValue" maxOccurs="unbounded" minOccurs="0"></xsd:element>
 					</xsd:sequence>
@@ -196,7 +196,7 @@
 			<xsd:element name="to" type="cms:ParentReference" maxOccurs="1" minOccurs="0" nillable="true"></xsd:element>
 			<xsd:sequence>
 				<xsd:element name="to_id" type="xsd:string" maxOccurs="1" minOccurs="0" nillable="true"></xsd:element>
-				<xsd:group ref="cms:ChildAssociation" maxOccurs="1" minOccurs="0" nillable="true"></xsd:group>
+				<xsd:group ref="cms:ChildAssociation" maxOccurs="1" minOccurs="0"></xsd:group>
 			</xsd:sequence>
 		</xsd:choice>
 	</xsd:group>