diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index e68223329c..0cbf570a13 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -3020,6 +3020,11 @@
         is only valid when the specified storage volume is of 'file' or
         'block' type).
         <p>
+        The <code>source</code> element may also have the <code>index</code>
+        attribute with same semantics the <a href='#elementsDiskBackingStoreIndex'>
+        <code>index</code></a> attribute of <code>backingStore</code>
+        </p>
+        <p>
         The <code>source</code> element may contain the following sub elements:
         </p>
 
@@ -3228,7 +3233,7 @@
             by the backing store, see disk type attribute above for more
             details and possible values.
           </dd>
-          <dt><code>index</code></dt>
+          <dt><code><a id="elementsDiskBackingStoreIndex">index</a></code></dt>
           <dd>
             This attribute is only valid in output (and ignored on input) and
             it can be used to refer to a specific part of the disk chain when
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 385fa8666c..f176538195 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -1545,6 +1545,14 @@
     </optional>
   </define>
 
+  <define name="diskSourceCommon">
+    <optional>
+      <attribute name="index">
+        <ref name="positiveInteger"/>
+      </attribute>
+    </optional>
+  </define>
+
   <define name="diskSource">
     <choice>
       <ref name="diskSourceFile"/>
@@ -1568,6 +1576,7 @@
             <ref name="absFilePath"/>
           </attribute>
         </optional>
+        <ref name="diskSourceCommon"/>
         <optional>
           <ref name="storageStartupPolicy"/>
         </optional>
@@ -1592,6 +1601,7 @@
             <ref name="absFilePath"/>
           </attribute>
         </optional>
+        <ref name="diskSourceCommon"/>
         <optional>
           <ref name="storageStartupPolicy"/>
         </optional>
@@ -1617,6 +1627,7 @@
         <attribute name="dir">
           <ref name="absFilePath"/>
         </attribute>
+        <ref name="diskSourceCommon"/>
         <optional>
           <ref name="storageStartupPolicy"/>
         </optional>
@@ -1670,6 +1681,7 @@
         <attribute name="protocol">
           <value>rbd</value>
         </attribute>
+        <ref name="diskSourceCommon"/>
         <optional>
           <attribute name="name"/>
         </optional>
@@ -1709,6 +1721,7 @@
         <value>iscsi</value>
       </attribute>
       <attribute name="name"/>
+      <ref name="diskSourceCommon"/>
       <ref name="diskSourceNetworkHost"/>
       <optional>
         <ref name="diskAuth"/>
@@ -1731,6 +1744,7 @@
         </choice>
       </attribute>
       <attribute name="name"/>
+      <ref name="diskSourceCommon"/>
       <ref name="diskSourceNetworkHost"/>
       <optional>
         <ref name="encryption"/>
@@ -1749,6 +1763,7 @@
         </choice>
       </attribute>
       <attribute name="name"/>
+      <ref name="diskSourceCommon"/>
       <ref name="diskSourceNetworkHost"/>
       <optional>
         <ref name="encryption"/>
@@ -1769,6 +1784,7 @@
           <ref name="virYesNo"/>
         </attribute>
       </optional>
+      <ref name="diskSourceCommon"/>
       <ref name="diskSourceNetworkHost"/>
       <optional>
         <ref name="encryption"/>
@@ -1782,6 +1798,7 @@
         <value>gluster</value>
       </attribute>
       <attribute name="name"/>
+      <ref name="diskSourceCommon"/>
       <oneOrMore>
         <ref name="diskSourceNetworkHost"/>
       </oneOrMore>
@@ -1799,6 +1816,7 @@
         </choice>
       </attribute>
       <attribute name="name"/>
+      <ref name="diskSourceCommon"/>
       <optional>
         <attribute name="tls">
           <ref name="virYesNo"/>
@@ -1843,6 +1861,7 @@
             </choice>
           </attribute>
         </optional>
+        <ref name="diskSourceCommon"/>
         <optional>
           <ref name="storageStartupPolicy"/>
         </optional>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 6b43c78ca4..bde9fef914 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -9811,6 +9811,13 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,
 
             startupPolicy = virXMLPropString(cur, "startupPolicy");
 
+            if (!(flags & VIR_DOMAIN_DEF_PARSE_INACTIVE) &&
+                (tmp = virXMLPropString(cur, "index")) &&
+                virStrToLong_uip(tmp, NULL, 10, &def->src->id) < 0) {
+                virReportError(VIR_ERR_XML_ERROR, _("invalid disk index '%s'"), tmp);
+                goto error;
+            }
+            VIR_FREE(tmp);
         } else if (!target &&
                    virXMLNodeNameEqual(cur, "target")) {
             target = virXMLPropString(cur, "dev");
@@ -23979,6 +23986,7 @@ virDomainDiskSourceFormatInternal(virBufferPtr buf,
                                   int policy,
                                   unsigned int flags,
                                   bool skipSeclabels,
+                                  bool attrIndex,
                                   virDomainXMLOptionPtr xmlopt)
 {
     virBuffer attrBuf = VIR_BUFFER_INITIALIZER;
@@ -23995,6 +24003,9 @@ virDomainDiskSourceFormatInternal(virBufferPtr buf,
         virBufferEscapeString(&attrBuf, " startupPolicy='%s'",
                               virDomainStartupPolicyTypeToString(policy));
 
+    if (attrIndex && src->id != 0)
+        virBufferAsprintf(&attrBuf, " index='%u'", src->id);
+
     if (virDomainDiskSourceFormatPrivateData(&childBuf, src, flags, xmlopt) < 0)
         goto cleanup;
 
@@ -24017,7 +24028,8 @@ virDomainDiskSourceFormat(virBufferPtr buf,
                           unsigned int flags,
                           virDomainXMLOptionPtr xmlopt)
 {
-    return virDomainDiskSourceFormatInternal(buf, src, policy, flags, false, xmlopt);
+    return virDomainDiskSourceFormatInternal(buf, src, policy, flags, false,
+                                             false, xmlopt);
 }
 
 
@@ -24059,7 +24071,8 @@ virDomainDiskBackingStoreFormat(virBufferPtr buf,
 
     virBufferAsprintf(buf, "<format type='%s'/>\n", format);
     /* We currently don't output seclabels for backing chain element */
-    if (virDomainDiskSourceFormatInternal(buf, backingStore, 0, flags, true, xmlopt) < 0 ||
+    if (virDomainDiskSourceFormatInternal(buf, backingStore, 0, flags, true,
+                                          false, xmlopt) < 0 ||
         virDomainDiskBackingStoreFormat(buf, backingStore->backingStore,
                                         xmlopt, flags) < 0)
         return -1;
@@ -24325,8 +24338,8 @@ virDomainDiskDefFormat(virBufferPtr buf,
     if (def->src->auth && !def->src->authInherited)
         virStorageAuthDefFormat(buf, def->src->auth);
 
-    if (virDomainDiskSourceFormat(buf, def->src, def->startupPolicy,
-                                  flags, xmlopt) < 0)
+    if (virDomainDiskSourceFormatInternal(buf, def->src, def->startupPolicy,
+                                          flags, false, true, xmlopt) < 0)
         return -1;
 
     /* Don't format backingStore to inactive XMLs until the code for
diff --git a/tests/qemuxml2argvdata/disk-backing-chains-index.xml b/tests/qemuxml2argvdata/disk-backing-chains-index.xml
index 95b8a64cf8..5e0a03fbc4 100644
--- a/tests/qemuxml2argvdata/disk-backing-chains-index.xml
+++ b/tests/qemuxml2argvdata/disk-backing-chains-index.xml
@@ -16,7 +16,7 @@
     <emulator>/usr/bin/qemu-system-i686</emulator>
     <disk type='network' device='disk'>
       <driver name='qemu' type='qcow2'/>
-      <source protocol='gluster' name='Volume2/Image'>
+      <source protocol='gluster' name='Volume2/Image' index='2'>
         <host transport='unix' socket='/path/to/sock'/>
       </source>
       <backingStore type='file' index='1'>
@@ -27,7 +27,7 @@
     </disk>
     <disk type='network' device='disk'>
       <driver name='qemu' type='qcow2'/>
-      <source protocol='nbd' name='bar'>
+      <source protocol='nbd' name='bar' index='9'>
         <host transport='unix' socket='/var/run/nbdsock'/>
       </source>
       <backingStore type='block' index='8'>
@@ -61,7 +61,7 @@
     <disk type='network' device='disk'>
       <driver name='qemu' type='raw'/>
       <backingStore/>
-      <source protocol='gluster' name='Volume1/Image'>
+      <source protocol='gluster' name='Volume1/Image' index='10'>
         <host name='example.org' port='6000'/>
       </source>
       <target dev='vdc' bus='virtio'/>
@@ -71,7 +71,7 @@
       <auth username='myname'>
         <secret type='ceph' usage='mycluster_myname'/>
       </auth>
-      <source protocol='rbd' name='pool/image'>
+      <source protocol='rbd' name='pool/image' index='12'>
         <host name='mon1.example.org' port='6321'/>
         <host name='mon2.example.org' port='6322'/>
         <host name='mon3.example.org' port='6322'/>
@@ -85,12 +85,12 @@
     </disk>
     <disk type='block' device='disk'>
       <driver name='qemu' type='qcow2'/>
-      <source dev='/dev/HostVG/QEMUGuest11'/>
+      <source dev='/dev/HostVG/QEMUGuest11' index='13'/>
       <target dev='vde' bus='virtio'/>
     </disk>
     <disk type='file' device='disk'>
       <driver name='qemu' type='qcow2'/>
-      <source file='/var/lib/libvirt/images/rhel7.1484071880'/>
+      <source file='/var/lib/libvirt/images/rhel7.1484071880' index='25'/>
       <backingStore type='file' index='24'>
         <format type='qcow2'/>
         <source file='/var/lib/libvirt/images/rhel7.1484071877'/>
diff --git a/tests/qemuxml2xmloutdata/disk-backing-chains-index-active.xml b/tests/qemuxml2xmloutdata/disk-backing-chains-index-active.xml
index 724afa4e83..2b5bc9e1b4 100644
--- a/tests/qemuxml2xmloutdata/disk-backing-chains-index-active.xml
+++ b/tests/qemuxml2xmloutdata/disk-backing-chains-index-active.xml
@@ -16,7 +16,7 @@
     <emulator>/usr/bin/qemu-system-i686</emulator>
     <disk type='network' device='disk'>
       <driver name='qemu' type='qcow2'/>
-      <source protocol='gluster' name='Volume2/Image'>
+      <source protocol='gluster' name='Volume2/Image' index='2'>
         <host transport='unix' socket='/path/to/sock'/>
       </source>
       <backingStore type='file' index='1'>
@@ -28,7 +28,7 @@
     </disk>
     <disk type='network' device='disk'>
       <driver name='qemu' type='qcow2'/>
-      <source protocol='nbd' name='bar'>
+      <source protocol='nbd' name='bar' index='9'>
         <host transport='unix' socket='/var/run/nbdsock'/>
       </source>
       <backingStore type='block' index='8'>
@@ -61,7 +61,7 @@
     </disk>
     <disk type='network' device='disk'>
       <driver name='qemu' type='raw'/>
-      <source protocol='gluster' name='Volume1/Image'>
+      <source protocol='gluster' name='Volume1/Image' index='10'>
         <host name='example.org' port='6000'/>
       </source>
       <backingStore/>
@@ -73,7 +73,7 @@
       <auth username='myname'>
         <secret type='ceph' usage='mycluster_myname'/>
       </auth>
-      <source protocol='rbd' name='pool/image'>
+      <source protocol='rbd' name='pool/image' index='12'>
         <host name='mon1.example.org' port='6321'/>
         <host name='mon2.example.org' port='6322'/>
         <host name='mon3.example.org' port='6322'/>
@@ -88,13 +88,13 @@
     </disk>
     <disk type='block' device='disk'>
       <driver name='qemu' type='qcow2'/>
-      <source dev='/dev/HostVG/QEMUGuest11'/>
+      <source dev='/dev/HostVG/QEMUGuest11' index='13'/>
       <target dev='vde' bus='virtio'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
     </disk>
     <disk type='file' device='disk'>
       <driver name='qemu' type='qcow2'/>
-      <source file='/var/lib/libvirt/images/rhel7.1484071880'/>
+      <source file='/var/lib/libvirt/images/rhel7.1484071880' index='25'/>
       <backingStore type='file' index='24'>
         <format type='qcow2'/>
         <source file='/var/lib/libvirt/images/rhel7.1484071877'/>