diff --git a/DnsServerCore/Dhcp/DhcpServer.cs b/DnsServerCore/Dhcp/DhcpServer.cs
index f7806d22b..4ad42b5c0 100644
--- a/DnsServerCore/Dhcp/DhcpServer.cs
+++ b/DnsServerCore/Dhcp/DhcpServer.cs
@@ -655,7 +655,14 @@ private Scope FindScope(DhcpMessage request, IPAddress remoteAddress, IPPacketIn
                     {
                         Scope scope = entry.Value;
 
-                        if (scope.Enabled && scope.IsAddressInRange(request.ClientIpAddress))
+                        if (!scope.Enabled)
+                            continue;
+
+                        Lease reservedLease = scope.GetReservedLease(request);
+                        if ((reservedLease is not null) && reservedLease.Address.Equals(request.ClientIpAddress))
+                            return scope; //ciaddr is this client's reserved address (may be out of pool range)
+
+                        if (scope.IsAddressInRange(request.ClientIpAddress))
                             return scope;
                     }
 
diff --git a/DnsServerCore/Dhcp/Scope.cs b/DnsServerCore/Dhcp/Scope.cs
index 4486dd566..4240c23f8 100644
--- a/DnsServerCore/Dhcp/Scope.cs
+++ b/DnsServerCore/Dhcp/Scope.cs
@@ -1477,6 +1477,9 @@ public void ChangeNetwork(IPAddress startingAddress, IPAddress endingAddress, IP
 
         public bool TryAddReservedLease(Lease reservedLease)
         {
+            if (!IsAddressInNetwork(reservedLease.Address))
+                throw new ArgumentOutOfRangeException(nameof(reservedLease), "Reserved address must be within the scope's subnet.");
+
             if (_reservedLeases.TryAdd(reservedLease.ClientIdentifier, reservedLease))
             {
                 _dhcpServer.AddDnsEntries(this, reservedLease);
@@ -2175,8 +2178,8 @@ public IReadOnlyCollection<Lease> ReservedLeases
                 {
                     foreach (Lease reservedLease in value)
                     {
-                        if (!IsAddressInRange(reservedLease.Address))
-                            throw new ArgumentOutOfRangeException(nameof(ReservedLeases), "Reserved address must be in scope range.");
+                        if (!IsAddressInNetwork(reservedLease.Address))
+                            throw new ArgumentOutOfRangeException(nameof(ReservedLeases), "Reserved address must be within the scope's subnet.");
                     }
 
                     //remove DNS entries for reserved leases being removed or has updated domain name