diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 5c0a00350b..bfcdc026e6 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -175,7 +175,11 @@
         and <a id="attributeOSTypeMachine"><code>machine</code></a> referring
         to the machine type. The <a href="formatcaps.html">Capabilities XML</a>
         provides details on allowed values for
-        these. <span class="since">Since 0.0.1</span></dd>
+        these. If <code>arch</code> is omitted then for most hypervisor
+        drivers, the host native arch will be chosen. For the <code>test</code>,
+        <code>ESX</code> and <code>VMWare</code> hypervisor drivers, however,
+        the <code>i686</code> arch will always be chosen even on an
+        <code>x86_64</code> host. <span class="since">Since 0.0.1</span></dd>
       <dt><a id="elementLoader"><code>loader</code></a></dt>
       <dd>The optional <code>loader</code> tag refers to a firmware blob,
         which is specified by absolute path,
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index a7a89b61b9..3d36bb9ac9 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -19613,6 +19613,7 @@ virDomainCachetuneDefParse(virDomainDefPtr def,
 static int
 virDomainDefParseCaps(virDomainDefPtr def,
                       xmlXPathContextPtr ctxt,
+                      virDomainXMLOptionPtr xmlopt,
                       virCapsPtr caps,
                       unsigned int flags)
 {
@@ -19673,6 +19674,13 @@ virDomainDefParseCaps(virDomainDefPtr def,
         return -1;
     }
 
+    if (def->os.arch == VIR_ARCH_NONE) {
+        if (xmlopt && xmlopt->config.defArch != VIR_ARCH_NONE)
+            def->os.arch = xmlopt->config.defArch;
+        else
+            def->os.arch = virArchFromHost();
+    }
+
     if (!(capsdata = virCapabilitiesDomainDataLookup(caps, def->os.type,
                                                      def->os.arch,
                                                      def->virtType,
@@ -19681,8 +19689,6 @@ virDomainDefParseCaps(virDomainDefPtr def,
             return -1;
         virResetLastError();
     } else {
-        if (!def->os.arch)
-            def->os.arch = capsdata->arch;
         if (!def->os.machine)
             def->os.machine = g_strdup(capsdata->machinetype);
     }
@@ -19840,7 +19846,7 @@ virDomainDefParseXML(xmlDocPtr xml,
             id = -1;
     def->id = (int)id;
 
-    if (virDomainDefParseCaps(def, ctxt, caps, flags) < 0)
+    if (virDomainDefParseCaps(def, ctxt, xmlopt, caps, flags) < 0)
         goto error;
 
     /* Extract domain name */
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 6b70eda14e..462323ec76 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -2705,6 +2705,7 @@ struct _virDomainDefParserConfig {
     /* data */
     unsigned int features; /* virDomainDefFeatures */
     unsigned char macPrefix[VIR_MAC_PREFIX_BUFLEN];
+    virArch defArch;
 };
 
 typedef void *(*virDomainXMLPrivateDataAllocFunc)(void *);
diff --git a/src/test/test_driver.c b/src/test/test_driver.c
index e7ec537bb0..f2700d90bc 100644
--- a/src/test/test_driver.c
+++ b/src/test/test_driver.c
@@ -424,6 +424,7 @@ testDriverNew(void)
                     VIR_DOMAIN_DEF_FEATURE_USER_ALIAS |
                     VIR_DOMAIN_DEF_FEATURE_FW_AUTOSELECT |
                     VIR_DOMAIN_DEF_FEATURE_NET_MODEL_STRING,
+        .defArch = VIR_ARCH_I686,
     };
     virDomainXMLPrivateDataCallbacks privatecb = {
         .alloc = testDomainObjPrivateAlloc,
diff --git a/src/vmware/vmware_driver.c b/src/vmware/vmware_driver.c
index c0071fc18c..bab4fdb82b 100644
--- a/src/vmware/vmware_driver.c
+++ b/src/vmware/vmware_driver.c
@@ -139,6 +139,7 @@ vmwareDomainDeviceDefPostParse(virDomainDeviceDefPtr dev G_GNUC_UNUSED,
 virDomainDefParserConfig vmwareDomainDefParserConfig = {
     .devicesPostParseCallback = vmwareDomainDeviceDefPostParse,
     .domainPostParseCallback = vmwareDomainDefPostParse,
+    .defArch = VIR_ARCH_I686,
 };
 
 static virDomainXMLOptionPtr
diff --git a/src/vmx/vmx.c b/src/vmx/vmx.c
index 0ccc4eefe6..c4af7b1ce9 100644
--- a/src/vmx/vmx.c
+++ b/src/vmx/vmx.c
@@ -556,6 +556,7 @@ static virDomainDefParserConfig virVMXDomainDefParserConfig = {
     .features = (VIR_DOMAIN_DEF_FEATURE_WIDE_SCSI |
                  VIR_DOMAIN_DEF_FEATURE_NAME_SLASH |
                  VIR_DOMAIN_DEF_FEATURE_NO_BOOT_ORDER),
+    .defArch = VIR_ARCH_I686,
 };
 
 struct virVMXDomainDefNamespaceData {