diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 9df05c4c2..49f4fa2ac 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -3288,14 +3288,20 @@ out:
 static void
 dp_netdev_get_mega_ufid(const struct match *match, ovs_u128 *mega_ufid)
 {
-    struct flow masked_flow;
+    struct {
+        struct flow masked_flow;
+        struct flow wc;
+    } key;
     size_t i;
 
+    memset(&key, 0, sizeof key);
     for (i = 0; i < sizeof(struct flow); i++) {
-        ((uint8_t *)&masked_flow)[i] = ((uint8_t *)&match->flow)[i] &
-                                       ((uint8_t *)&match->wc)[i];
+        ((uint8_t *)&key.masked_flow)[i] = ((uint8_t *)&match->flow)[i] &
+                                           ((uint8_t *)&match->wc)[i];
+        ((uint8_t *)&key.wc)[i] = ((uint8_t *)&match->wc)[i];
     }
-    odp_flow_key_hash(&masked_flow, sizeof masked_flow, mega_ufid);
+
+    odp_flow_key_hash(&key, sizeof key, mega_ufid);
 }
 
 uint64_t
diff --git a/tests/dpif-netdev.at b/tests/dpif-netdev.at
index 231197970..b0eb9ea63 100644
--- a/tests/dpif-netdev.at
+++ b/tests/dpif-netdev.at
@@ -668,6 +668,31 @@ AT_CHECK([ovs-appctl revalidator/resume])
 OVS_VSWITCHD_STOP
 AT_CLEANUP
 
+AT_SETUP([dpif-netdev - mega flow ufid uniqueness for different wildcards])
+OVS_VSWITCHD_START(
+  [add-port br0 p1 \
+   -- set interface p1 type=dummy options:pstream=punix:$OVS_RUNDIR/p0.sock \
+   -- set bridge br0 datapath-type=dummy])
+AT_CHECK([ovs-appctl vlog/set dpif_netdev:dbg])
+AT_CHECK([ovs-appctl vlog/disable-rate-limit dpif_netdev])
+
+AT_CHECK([ovs-appctl revalidator/pause])
+# Two flows with different wildcard masks but identical masked flow.
+# Flow A: tos=0x20 with mask 0 (wildcarded) -> masked tos = 0
+# Flow B: tos=0x00 with exact match         -> masked tos = 0
+AT_CHECK([ovs-appctl dpctl/add-flow "in_port(1),eth(),eth_type(0x0800),ipv4(src=10.0.0.1,dst=10.0.0.2,proto=6,tos=0x20/0,ttl=64,frag=no),tcp(src=80,dst=8080)" "3"])
+AT_CHECK([ovs-appctl dpctl/add-flow "in_port(1),eth(),eth_type(0x0800),ipv4(src=10.0.0.1,dst=10.0.0.2,proto=6,tos=0,ttl=64,frag=no),tcp(src=80,dst=8080)" "3"])
+
+AT_CHECK([ovs-appctl revalidator/resume])
+
+# Verify both flows have different mega_ufids by checking flow_add log.
+AT_CHECK([grep 'flow_add.*tcp(src=80,dst=8080)' ovs-vswitchd.log | sed -n 's/.*mega_ufid:\([[0-9a-f-]]*\).*/\1/p' | sort -u | wc -l | tr -d ' '], [0], [dnl
+2
+])
+
+OVS_VSWITCHD_STOP
+AT_CLEANUP
+
 AT_SETUP([dpif-netdev - check tx packet checksum offloading])
 OVS_VSWITCHD_START(
   [add-port br0 p1 \