diff --git a/src/opnsense/mvc/app/models/OPNsense/Kea/KeaDhcpv4.xml b/src/opnsense/mvc/app/models/OPNsense/Kea/KeaDhcpv4.xml
index 950bcc2c8..17b2c5944 100644
--- a/src/opnsense/mvc/app/models/OPNsense/Kea/KeaDhcpv4.xml
+++ b/src/opnsense/mvc/app/models/OPNsense/Kea/KeaDhcpv4.xml
@@ -120,6 +120,12 @@
                 <ip_address type="NetworkField">
                     <NetMaskAllowed>N</NetMaskAllowed>
                     <AddressFamily>ipv4</AddressFamily>
+                    <Constraints>
+                        <check001>
+                            <ValidationMessage>Duplicate entry exists</ValidationMessage>
+                            <type>UniqueConstraint</type>
+                        </check001>
+                    </Constraints>
                 </ip_address>
                 <hw_address type="MacAddressField">
                     <Required>Y</Required>