diff --git a/dhcpd/dhcpd.go b/dhcpd/dhcpd.go
index 86aa6fa9..27233965 100644
--- a/dhcpd/dhcpd.go
+++ b/dhcpd/dhcpd.go
@@ -369,7 +369,6 @@ func (s *Server) handleDiscover(p dhcp4.Packet, options dhcp4.Options) dhcp4.Pac
 
 func (s *Server) handleDHCP4Request(p dhcp4.Packet, options dhcp4.Options) dhcp4.Packet {
 	var lease *Lease
-	var err error
 
 	reqIP := net.IP(options[dhcp4.OptionRequestedIPAddress])
 	log.Tracef("Message from client: Request.  IP: %s  ReqIP: %s  HW: %s",
@@ -395,12 +394,8 @@ func (s *Server) handleDHCP4Request(p dhcp4.Packet, options dhcp4.Options) dhcp4
 
 	lease = s.findLease(p)
 	if lease == nil {
-		lease, err = s.reserveLease(p)
-		if err != nil {
-			log.Tracef("Couldn't find free lease: %s", err)
-			// couldn't find lease, don't respond
-			return nil
-		}
+		log.Tracef("Lease for %s isn't found", p.CHAddr())
+		return dhcp4.ReplyPacket(p, dhcp4.NAK, s.ipnet.IP, nil, 0, nil)
 	}
 
 	if !lease.IP.Equal(reqIP) {
diff --git a/dhcpd/dhcpd_test.go b/dhcpd/dhcpd_test.go
index 2d675ed9..366606d4 100644
--- a/dhcpd/dhcpd_test.go
+++ b/dhcpd/dhcpd_test.go
@@ -43,11 +43,7 @@ func TestDHCP(t *testing.T) {
 	lease, _ = s.reserveLease(p)
 	check(t, bytes.Equal(lease.HWAddr, hw), "lease.HWAddr")
 	check(t, bytes.Equal(lease.IP, []byte{1, 1, 1, 1}), "lease.IP")
-
-	// Try to reserve another IP for the same machine - no new IP must be reserved
-	hw = []byte{1, 2, 3, 4, 5, 6}
-	p.SetCHAddr(hw)
-	lease, _ = s.reserveLease(p)
+	lease = s.findLease(p)
 	check(t, bytes.Equal(lease.HWAddr, hw), "lease.HWAddr")
 	check(t, bytes.Equal(lease.IP, []byte{1, 1, 1, 1}), "lease.IP")
 
@@ -100,7 +96,7 @@ func misc(t *testing.T, s *Server) {
 
 	p = make(dhcp4.Packet, 241)
 
-	// Commit a lease for an IP without prior Discover-Offer packets
+	// Try to commit a lease for an IP without prior Discover-Offer packets
 	hw = []byte{2, 2, 3, 4, 5, 6}
 	p.SetCHAddr(hw)
 	p.SetCIAddr([]byte{0, 0, 0, 0})
@@ -108,11 +104,7 @@ func misc(t *testing.T, s *Server) {
 	opt[dhcp4.OptionRequestedIPAddress] = []byte{1, 1, 1, 1}
 	p2 = s.handleDHCP4Request(p, opt)
 	opt = p2.ParseOptions()
-	check(t, bytes.Equal(opt[dhcp4.OptionDHCPMessageType], []byte{byte(dhcp4.ACK)}), "dhcp4.ACK")
-	check(t, bytes.Equal(p2.YIAddr(), []byte{1, 1, 1, 1}), "p2.YIAddr")
-	check(t, bytes.Equal(p2.CHAddr(), hw), "p2.CHAddr")
-	check(t, bytes.Equal(opt[dhcp4.OptionIPAddressLeaseTime], dhcp4.OptionsLeaseTime(5*time.Second)), "OptionIPAddressLeaseTime")
-	check(t, bytes.Equal(opt[dhcp4.OptionServerIdentifier], s.ipnet.IP), "OptionServerIdentifier")
+	check(t, bytes.Equal(opt[dhcp4.OptionDHCPMessageType], []byte{byte(dhcp4.NAK)}), "dhcp4.NAK")
 }
 
 // Leases database store/load