diff --git a/misc/config_tools/schema/types.xsd b/misc/config_tools/schema/types.xsd
index e4e7eefc0..6cfd562cd 100644
--- a/misc/config_tools/schema/types.xsd
+++ b/misc/config_tools/schema/types.xsd
@@ -198,7 +198,7 @@ Read more about the available scheduling options in :ref:`cpu_sharing`.</xs:docu
 
 <xs:complexType name="IVSHMEMVM">
   <xs:sequence>
-   <xs:element name="VM_NAME" type="VMNameType">
+   <xs:element name="VM_NAME" type="VMNameType" minOccurs="1">
      <xs:annotation acrn:title="Shared VMs">
        <xs:documentation>Name of the VM that uses this shared memory region.</xs:documentation>
      </xs:annotation>