diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c
--- a/sys/netpfil/pf/pf.c
+++ b/sys/netpfil/pf/pf.c
@@ -6002,6 +6002,7 @@
 
 		uma_zfree(V_pf_state_key_z, sk);
 		uma_zfree(V_pf_state_key_z, nk);
+		sk = nk = NULL;
 		pf_udp_mapping_release(udp_mapping);
 	}