diff --git a/public/wsdl/Methods_AMDA.wsdl b/public/wsdl/Methods_AMDA.wsdl
index 6121870..eb6dc9f 100644
--- a/public/wsdl/Methods_AMDA.wsdl
+++ b/public/wsdl/Methods_AMDA.wsdl
@@ -95,7 +95,7 @@
 
             <xs:complexType name="getParameterList">
                 <xs:sequence>
-                    <xs:element name="userID" type="xs:string" minOccurs="1" maxOccurs="1">
+                    <xs:element name="userID" type="xs:string" minOccurs="0" maxOccurs="1">
                         <xs:annotation>
                             <xs:documentation>ID of AMDA user. If no user ID, user is IMPEX</xs:documentation>
                         </xs:annotation>
--
libgit2 0.21.2