diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 77c982d676..15e182b5d7 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -4393,6 +4393,10 @@ virQEMUCapsInitQMPVersionCaps(virQEMUCapsPtr qemuCaps)
         ARCH_IS_PPC64(qemuCaps->arch)) {
         virQEMUCapsSet(qemuCaps, QEMU_CAPS_MACHINE_PSERIES_MAX_CPU_COMPAT);
     }
+
+    /* -net socket,fd= with dgram socket (for ex, with slirp helper) */
+    if (qemuCaps->version >= 4000000)
+        virQEMUCapsSet(qemuCaps, QEMU_CAPS_NET_SOCKET_DGRAM);
 }
 
 
diff --git a/tests/qemucapabilitiesdata/caps_4.0.0.aarch64.xml b/tests/qemucapabilitiesdata/caps_4.0.0.aarch64.xml
index 20f119665b..1627b2cb5e 100644
--- a/tests/qemucapabilitiesdata/caps_4.0.0.aarch64.xml
+++ b/tests/qemucapabilitiesdata/caps_4.0.0.aarch64.xml
@@ -165,6 +165,7 @@
   <flag name='nbd-bitmap'/>
   <flag name='bochs-display'/>
   <flag name='migration-file-drop-cache'/>
+  <flag name='net-socket-dgram'/>
   <version>4000000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>61700758</microcodeVersion>
diff --git a/tests/qemucapabilitiesdata/caps_4.0.0.ppc64.xml b/tests/qemucapabilitiesdata/caps_4.0.0.ppc64.xml
index 9ea6f4d046..73859becab 100644
--- a/tests/qemucapabilitiesdata/caps_4.0.0.ppc64.xml
+++ b/tests/qemucapabilitiesdata/caps_4.0.0.ppc64.xml
@@ -170,6 +170,7 @@
   <flag name='nbd-bitmap'/>
   <flag name='bochs-display'/>
   <flag name='migration-file-drop-cache'/>
+  <flag name='net-socket-dgram'/>
   <version>4000000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>42900758</microcodeVersion>
diff --git a/tests/qemucapabilitiesdata/caps_4.0.0.riscv32.xml b/tests/qemucapabilitiesdata/caps_4.0.0.riscv32.xml
index 7503c2dbcd..ab6a774c3f 100644
--- a/tests/qemucapabilitiesdata/caps_4.0.0.riscv32.xml
+++ b/tests/qemucapabilitiesdata/caps_4.0.0.riscv32.xml
@@ -168,6 +168,7 @@
   <flag name='nbd-bitmap'/>
   <flag name='bochs-display'/>
   <flag name='migration-file-drop-cache'/>
+  <flag name='net-socket-dgram'/>
   <version>4000000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>0</microcodeVersion>
diff --git a/tests/qemucapabilitiesdata/caps_4.0.0.riscv64.xml b/tests/qemucapabilitiesdata/caps_4.0.0.riscv64.xml
index 4a94179ee7..f731e7b4fa 100644
--- a/tests/qemucapabilitiesdata/caps_4.0.0.riscv64.xml
+++ b/tests/qemucapabilitiesdata/caps_4.0.0.riscv64.xml
@@ -168,6 +168,7 @@
   <flag name='nbd-bitmap'/>
   <flag name='bochs-display'/>
   <flag name='migration-file-drop-cache'/>
+  <flag name='net-socket-dgram'/>
   <version>4000000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>0</microcodeVersion>
diff --git a/tests/qemucapabilitiesdata/caps_4.0.0.s390x.xml b/tests/qemucapabilitiesdata/caps_4.0.0.s390x.xml
index ef802f3d1f..6cad000a11 100644
--- a/tests/qemucapabilitiesdata/caps_4.0.0.s390x.xml
+++ b/tests/qemucapabilitiesdata/caps_4.0.0.s390x.xml
@@ -132,6 +132,7 @@
   <flag name='bitmap-merge'/>
   <flag name='nbd-bitmap'/>
   <flag name='migration-file-drop-cache'/>
+  <flag name='net-socket-dgram'/>
   <version>4000000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>39100758</microcodeVersion>
diff --git a/tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml b/tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml
index 87c95f4d18..79593c467a 100644
--- a/tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml
+++ b/tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml
@@ -207,6 +207,7 @@
   <flag name='x86-max-cpu'/>
   <flag name='bochs-display'/>
   <flag name='migration-file-drop-cache'/>
+  <flag name='net-socket-dgram'/>
   <version>4000000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>43100758</microcodeVersion>
diff --git a/tests/qemucapabilitiesdata/caps_4.1.0.x86_64.xml b/tests/qemucapabilitiesdata/caps_4.1.0.x86_64.xml
index f4583d7fe7..05e6538e37 100644
--- a/tests/qemucapabilitiesdata/caps_4.1.0.x86_64.xml
+++ b/tests/qemucapabilitiesdata/caps_4.1.0.x86_64.xml
@@ -209,6 +209,7 @@
   <flag name='canonical-cpu-features'/>
   <flag name='bochs-display'/>
   <flag name='migration-file-drop-cache'/>
+  <flag name='net-socket-dgram'/>
   <version>4000050</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>43100759</microcodeVersion>
diff --git a/tests/qemuxml2argvdata/net-user.x86_64-4.0.0.args b/tests/qemuxml2argvdata/net-user.x86_64-4.0.0.args
index 3fb745c212..d51653dcdd 100644
--- a/tests/qemuxml2argvdata/net-user.x86_64-4.0.0.args
+++ b/tests/qemuxml2argvdata/net-user.x86_64-4.0.0.args
@@ -29,7 +29,7 @@ file=/tmp/lib/domain--1-QEMUGuest1/master-key.aes \
 -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 \
 -drive file=/dev/HostVG/QEMUGuest1,format=raw,if=none,id=drive-ide0-0-0 \
 -device ide-hd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 \
--netdev user,id=hostnet0 \
+-netdev socket,fd=42,id=hostnet0 \
 -device rtl8139,netdev=hostnet0,id=net0,mac=00:11:22:33:44:55,bus=pci.0,\
 addr=0x2 \
 -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,\