diff --git a/bin/propolis-server/src/lib/initializer.rs b/bin/propolis-server/src/lib/initializer.rs
index 8e5d4961b..2da276829 100644
--- a/bin/propolis-server/src/lib/initializer.rs
+++ b/bin/propolis-server/src/lib/initializer.rs
@@ -771,6 +771,12 @@ impl MachineInitializer<'_> {
             info!(self.log, "Creating vNIC {}", device_name);
             let bdf: pci::Bdf = nic.device_spec.pci_path.into();
 
+            if virtio::viona::api_version().expect("can query viona version")
+                < virtio::viona::ApiVersion::V6
+            {
+                panic!("Kernel viona API is too old; need >= V6");
+            }
+
             // Set viona device parameters if possible.
             //
             // The values chosen here are tuned to maximize performance when
diff --git a/bin/propolis-standalone/src/main.rs b/bin/propolis-standalone/src/main.rs
index cc5a1d31c..c309697b5 100644
--- a/bin/propolis-standalone/src/main.rs
+++ b/bin/propolis-standalone/src/main.rs
@@ -1247,6 +1247,13 @@ fn setup_instance(
                         dev.options.get("vnic").unwrap().as_str().unwrap();
                     let bdf = bdf.unwrap();
 
+                    if hw::virtio::viona::api_version()
+                        .expect("can query viona version")
+                        < hw::virtio::viona::ApiVersion::V6
+                    {
+                        panic!("Kernel viona API is too old; need >= V6");
+                    }
+
                     let viona_params =
                         config::VionaDeviceParams::from_opts(&dev.options)
                             .expect("viona params are valid");