diff --git a/resources/schema/semantic_types.xsd b/resources/schema/semantic_types.xsd
index 128b7aa..07c83ea 100644
--- a/resources/schema/semantic_types.xsd
+++ b/resources/schema/semantic_types.xsd
@@ -17,6 +17,7 @@
       <xsd:element name="name" type="nameType"/>
       <xsd:element name="semanticType" minOccurs="0" maxOccurs="unbounded"/>
     </xsd:sequence>
+    <xsd:attribute name="id" type="xsd:int"/>
     <xsd:attribute name="SEMCODE" type="xsd:string"/>
   </xsd:complexType>