diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 6f970a3128..3eff09a9d3 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -8149,7 +8149,7 @@ qemuBuildInterfaceCommandLine(virQEMUDriverPtr driver,
         }
     }
 
-    if (net->mtu &&
+    if (net->mtu && net->managed_tap != VIR_TRISTATE_BOOL_NO &&
         virNetDevSetMTU(net->ifname, net->mtu) < 0)
         goto cleanup;
 
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index f336a90c8e..95f2bd0aca 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -1387,7 +1387,7 @@ qemuDomainAttachNetDevice(virQEMUDriverPtr driver,
         }
     }
 
-    if (net->mtu &&
+    if (net->mtu && net->managed_tap != VIR_TRISTATE_BOOL_NO &&
         virNetDevSetMTU(net->ifname, net->mtu) < 0)
         goto cleanup;