diff --git a/lib/ipf.c b/lib/ipf.c
index 6670ef5a9..b16797312 100644
--- a/lib/ipf.c
+++ b/lib/ipf.c
@@ -1193,6 +1193,9 @@ ipf_post_execute_reass_pkts(struct ipf *ipf,
                 const struct ipf_frag *frag_0 = &rp->list->frag_list[0];
                 void *l4_frag = dp_packet_l4(frag_0->pkt);
                 void *l4_reass = dp_packet_l4(pkt);
+
+                /* Complete all L4 checksums before reassembly. */
+                dp_packet_ol_send_prepare(pkt, 0);
                 memcpy(l4_frag, l4_reass, dp_packet_l4_size(frag_0->pkt));
 
                 for (int i = 0; i <= rp->list->last_inuse_idx; i++) {
diff --git a/tests/ofproto-dpif.at b/tests/ofproto-dpif.at
index 46b1e6707..a0cd4a5ce 100644
--- a/tests/ofproto-dpif.at
+++ b/tests/ofproto-dpif.at
@@ -11665,6 +11665,57 @@ OVS_WAIT_UNTIL([ovs-pcap p1-tx.pcap | grep -q "$packet3"])
 OVS_VSWITCHD_STOP
 AT_CLEANUP
 
+AT_SETUP([ofproto-dpif - conntrack - fragmentation nat])
+OVS_VSWITCHD_START
+
+add_of_ports --pcap br0 1 2
+
+AT_DATA([flows.txt], [dnl
+table=0,priority=10,ip,in_port=1,udp,action=ct(commit,table=1,nat(dst=1.2.3.4))
+table=1,priority=10,ip,in_port=1,udp,action=2
+])
+
+AT_CHECK([ovs-ofctl add-flows br0 flows.txt])
+
+dnl Set min frag size.
+AT_CHECK([ovs-appctl dpctl/ipf-set-min-frag v4 400], [], [dnl
+setting minimum fragment size successful
+])
+
+dnl First UDP fragment.
+AT_CHECK(dnl
+[ovs-ofctl -O OpenFlow13 packet-out br0 "in_port=1 packet=]dnl
+[c6f94ecb72dbe64c473528c9080045000204317020004011cf55ac100001ac100002a28e15b3]dnl
+[01fc31d741414141414141414141414141414141414141414141414141414141414141414141]dnl
+[4141414141414141414141414141414141414141414141414141414141414141414141414141]dnl
+[4141414141414141414141414141414141414141414141414141414141414141414141414141]dnl
+[4141414141414141414141414141414141414141414141414141414141414141414141414141]dnl
+[4141414141414141414141414141414141414141414141414141414141414141414141414141]dnl
+[4141414141414141414141414141414141414141414141414141414141414141414141414141]dnl
+[4141414141414141414141414141414141414141414141414141414141414141414141414141]dnl
+[4141414141414141414141414141414141414141414141414141414141414141414141414141]dnl
+[4141414141414141414141414141414141414141414141414141414141414141414141414141]dnl
+[4141414141414141414141414141414141414141414141414141414141414141414141414141]dnl
+[4141414141414141414141414141414141414141414141414141414141414141414141414141]dnl
+[4141414141414141414141414141414141414141414141414141414141414141414141414141]dnl
+[414141414141414141414141414141414141414141414141414141414141414141414141]dnl
+[ actions=resubmit(,0)"])
+
+dnl Second UDP fragment.
+AT_CHECK(dnl
+[ovs-ofctl -O OpenFlow13 packet-out br0 "in_port=1 packet=]dnl
+[c6f94ecb72dbe64c473528c90800450000203170003e4011f0fbac100001ac10000241414141]dnl
+[4141414141414141]dnl
+[ actions=resubmit(,0)"])
+
+dnl Validate that both IP headers now have the correct IP address and
+dnl the UDP header has the correct checksum.
+OVS_WAIT_UNTIL([ovs-pcap p2-tx.pcap | grep -q "450002043170200040117762ac10000101020304a28e15b301fcd9e3"])
+OVS_WAIT_UNTIL([ovs-pcap p2-tx.pcap | grep -q "450000203170003e40119908ac10000101020304"])
+
+OVS_VSWITCHD_STOP
+AT_CLEANUP
+
 AT_SETUP([ofproto-dpif - conntrack - ipv6])
 OVS_VSWITCHD_START