diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index b8fbcf9d66..27ec1da66d 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -1276,7 +1276,11 @@
       </optional>
       <optional>
         <element name="model">
-          <attribute name="type"/>
+          <attribute name="type">
+            <data type="string">
+              <param name='pattern'>[a-zA-Z0-9\-_]+</param>
+            </data>
+          </attribute>
           <empty/>
         </element>
       </optional>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 75e51a06a2..d68ab10d0d 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -3385,6 +3385,9 @@ error:
     return ret;
 }
 
+#define NET_MODEL_CHARS \
+    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ091234567890_-"
+
 /* Parse the XML definition for a network interface
  * @param node XML nodeset to parse for net definition
  * @return 0 on success, -1 on failure
@@ -3699,16 +3702,13 @@ virDomainNetDefParseXML(virCapsPtr caps,
      * reasonable, not that it is a supported NIC type.  FWIW kvm
      * supports these types as of April 2008:
      * i82551 i82557b i82559er ne2k_pci pcnet rtl8139 e1000 virtio
+     * QEMU PPC64 supports spapr-vlan
      */
     if (model != NULL) {
-        int i;
-        for (i = 0 ; i < strlen(model) ; i++) {
-            int char_ok = c_isalnum(model[i]) || model[i] == '_';
-            if (!char_ok) {
-                virDomainReportError(VIR_ERR_INVALID_ARG, "%s",
-                                     _("Model name contains invalid characters"));
-                goto error;
-            }
+        if (strspn(model, NET_MODEL_CHARS) < strlen(model)) {
+            virDomainReportError(VIR_ERR_INVALID_ARG, "%s",
+                                 _("Model name contains invalid characters"));
+            goto error;
         }
         def->model = model;
         model = NULL;