diff --git a/src/util/virnetdevbandwidth.c b/src/util/virnetdevbandwidth.c
index c8a90c8522..8041d52697 100644
--- a/src/util/virnetdevbandwidth.c
+++ b/src/util/virnetdevbandwidth.c
@@ -83,6 +83,13 @@ virNetDevBandwidthSet(const char *ifname,
         return -1;
     }
 
+    if (!ifname) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("Unable to set bandwidth for interface because "
+                         "device name is unknown"));
+        return -1;
+    }
+
     virNetDevBandwidthClear(ifname);
 
     if (bandwidth->in && bandwidth->in->average) {
diff --git a/src/util/virnetdevbandwidth.h b/src/util/virnetdevbandwidth.h
index de289dbe04..efcf95af51 100644
--- a/src/util/virnetdevbandwidth.h
+++ b/src/util/virnetdevbandwidth.h
@@ -46,7 +46,7 @@ void virNetDevBandwidthFree(virNetDevBandwidthPtr def);
 int virNetDevBandwidthSet(const char *ifname,
                           virNetDevBandwidthPtr bandwidth,
                           bool hierarchical_class)
-    ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;
+    ATTRIBUTE_RETURN_CHECK;
 int virNetDevBandwidthClear(const char *ifname);
 int virNetDevBandwidthCopy(virNetDevBandwidthPtr *dest,
                            const virNetDevBandwidth *src)