diff --git a/schema/bom-1.6.xsd b/schema/bom-1.6.xsd
index f2685c70..51190564 100644
--- a/schema/bom-1.6.xsd
+++ b/schema/bom-1.6.xsd
@@ -7281,7 +7281,7 @@ limitations under the License.
                                             </xs:documentation>
                                         </xs:annotation>
                                     </xs:element>
-                                    <xs:element name="esn" type="xs:boolean" minOccurs="0" maxOccurs="unbounded">
+                                    <xs:element name="esn" type="xs:boolean" minOccurs="0" maxOccurs="1">
                                         <xs:annotation>
                                             <xs:documentation>
                                                 Specifies if an Extended Sequence Number (ESN) is used.