diff --git a/schema.xsd b/schema.xsd
index ca8f6b4..6d0032c 100644
--- a/schema.xsd
+++ b/schema.xsd
@@ -88,7 +88,7 @@
     <xsd:complexType name="Enum">
         <xsd:sequence>
             <xsd:element type="xsd:string" name="description" minOccurs="0"/>
-            <xsd:element type="EnumItemList" name="item-list" minOccurs="0"/>
+            <xsd:element type="EnumItemList" name="item-list"/>
         </xsd:sequence>
         <xsd:attribute type="xsd:string" name="name" use="required"/>
         <xsd:attribute type="xsd:boolean" name="noCount"/>
@@ -98,7 +98,7 @@
     <xsd:complexType name="Bitfield">
         <xsd:sequence>
             <xsd:element type="xsd:string" name="description" minOccurs="0"/>
-            <xsd:element type="BitfieldItemList" name="item-list" minOccurs="0"/>
+            <xsd:element type="BitfieldItemList" name="item-list"/>
         </xsd:sequence>
         <xsd:attribute type="xsd:string" name="name" use="required"/>
         <xsd:attribute type="xsd:int" name="size"/>