diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index e34e6ad372..d88947c131 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -30886,6 +30886,7 @@ virDomainNetDefToNetworkPort(virDomainDefPtr dom,
     if (virNetDevVlanCopy(&port->vlan, &iface->vlan) < 0)
         return NULL;
 
+    port->isolatedPort = iface->isolatedPort;
     port->trustGuestRxFilters = iface->trustGuestRxFilters;
 
     return g_steal_pointer(&port);
@@ -30985,6 +30986,7 @@ virDomainNetDefActualFromNetworkPort(virDomainNetDefPtr iface,
     if (virNetDevVlanCopy(&actual->vlan, &port->vlan) < 0)
         goto error;
 
+    actual->isolatedPort = port->isolatedPort;
     actual->class_id = port->class_id;
     actual->trustGuestRxFilters = port->trustGuestRxFilters;
 
@@ -31124,6 +31126,7 @@ virDomainNetDefActualToNetworkPort(virDomainDefPtr dom,
     if (virNetDevVlanCopy(&port->vlan, &actual->vlan) < 0)
         return NULL;
 
+    port->isolatedPort = actual->isolatedPort;
     port->class_id = actual->class_id;
     port->trustGuestRxFilters = actual->trustGuestRxFilters;
 
diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
index e826f608da..0048907f6c 100644
--- a/src/network/bridge_driver.c
+++ b/src/network/bridge_driver.c
@@ -4532,6 +4532,9 @@ networkAllocatePort(virNetworkObjPtr obj,
             port->trustGuestRxFilters = netdef->trustGuestRxFilters;
     }
 
+    if (port->isolatedPort == VIR_TRISTATE_BOOL_ABSENT)
+        port->isolatedPort = netdef->isolatedPort;
+
     /* merge virtualports from interface, network, and portgroup to
      * arrive at actual virtualport to use
      */