diff --git a/ChangeLog b/ChangeLog
index 39b10e9ecc28e97ad9eb862a2d42988faa3d662b..8e609f5c5195fae76240d70ca49208ece34c186b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jul 30 14:40:23 EST 2007 Daniel P. Berrange <berrange@redhat.com>
+
+	* src/qemu_conf.c: Validate requested architecture and reject
+	unsupported ones
+
 Mon Jul 30 12:15:43 CEST 2007 Daniel Veillard <veillard@redhat.com>
 
 	* src/xen_internal.c: add report of ACPI/APIC for Xen fully virt,
diff --git a/src/qemu_conf.c b/src/qemu_conf.c
index fbd0ba3c6584029085d05d496728e2cbe8a10ed7..4f88d21ca7f12291437bff17f060acfb143c5a87 100644
--- a/src/qemu_conf.c
+++ b/src/qemu_conf.c
@@ -1102,6 +1102,10 @@ static struct qemud_vm_def *qemudParseXML(virConnectPtr conn,
     if ((obj == NULL) || (obj->type != XPATH_STRING) ||
         (obj->stringval == NULL) || (obj->stringval[0] == 0)) {
         const char *defaultMachine = qemudDefaultMachineForArch(def->os.arch);
+        if (!defaultMachine) {
+            qemudReportError(conn, NULL, NULL, VIR_ERR_INTERNAL_ERROR, "unsupported arch %s", def->os.arch);
+            goto error;
+        }
         if (strlen(defaultMachine) >= (QEMUD_OS_MACHINE_MAX_LEN-1)) {
             qemudReportError(conn, NULL, NULL, VIR_ERR_INTERNAL_ERROR, "%s", "machine type too long");
             goto error;