diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 40e2b2979e1bc39e54b9054444cf8ded9fa5036b..8d989155419cda5182366c1b73b1899961d73400 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -5618,18 +5618,17 @@ qemu-kvm -net nic,model=? /dev/null
       <dt><code>period</code></dt>
       <dd>
         <p>
-          The optional <code>period</code> allows the QEMU virtio memory
-          balloon driver to provide statistics through the <code>virsh
-          dommemstat [domain]</code> command. By default, collection is
-          not enabled. In order to enable, use the <code>virsh dommemstat
-          [domain] --period [number]</code> command or <code>virsh edit</code>
-          command to add the option to the XML definition.
-          The <code>virsh dommemstat</code> will accept the options
-          <code>--live</code>, <code>--current</code>, or <code>--config</code>.
-          If an option is not provided, the change for a running domain will
-          only be made to the active guest.
-          If the QEMU driver is not at the right
-          revision, the attempt to set the period will fail.
+          The optional <code>period</code> allows the QEMU virtio memory balloon
+          driver to provide statistics through the <code>virsh dommemstat
+          [domain]</code> command. By default, collection is not enabled. In
+          order to enable, use the <code>virsh dommemstat [domain] --period
+          [number]</code> command or <code>virsh edit</code> command to add the
+          option to the XML definition.  The <code>virsh dommemstat</code> will
+          accept the options <code>--live</code>, <code>--current</code>,
+          or <code>--config</code>.  If an option is not provided, the change
+          for a running domain will only be made to the active guest.  If the
+          QEMU driver is not at the right revision, the attempt to set the
+          period will fail.  Large values (e.g. many years) might be ignored.
           <span class='since'>Since 1.1.1, requires QEMU 1.5</span>
         </p>
       </dd>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 3865854a5ca843ea891882d92cec5c4bf4f3bf31..c75b543593ac10f61d11496092fdac4a6fbc6a57 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -10492,6 +10492,7 @@ virDomainMemballoonDefParseXML(xmlNodePtr node,
     char *model;
     virDomainMemballoonDefPtr def;
     xmlNodePtr save = ctxt->node;
+    unsigned int period = 0;
 
     if (VIR_ALLOC(def) < 0)
         return NULL;
@@ -10510,12 +10511,16 @@ virDomainMemballoonDefParseXML(xmlNodePtr node,
     }
 
     ctxt->node = node;
-    if (virXPathUInt("string(./stats/@period)", ctxt, &def->period) < -1) {
+    if (virXPathUInt("string(./stats/@period)", ctxt, &period) < -1) {
         virReportError(VIR_ERR_XML_ERROR, "%s",
                        _("invalid statistics collection period"));
         goto error;
     }
 
+    def->period = period;
+    if (def->period < 0)
+        def->period = 0;
+
     if (def->model == VIR_DOMAIN_MEMBALLOON_MODEL_NONE)
         VIR_DEBUG("Ignoring device address for none model Memballoon");
     else if (virDomainDeviceInfoParseXML(node, NULL, &def->info, flags) < 0)
@@ -18839,7 +18844,7 @@ virDomainMemballoonDefFormat(virBufferPtr buf,
     virBufferAdjustIndent(&childrenBuf, indent + 2);
 
     if (def->period)
-        virBufferAsprintf(&childrenBuf, "<stats period='%u'/>\n", def->period);
+        virBufferAsprintf(&childrenBuf, "<stats period='%i'/>\n", def->period);
 
     if (virDomainDeviceInfoNeedsFormat(&def->info, flags) &&
         virDomainDeviceInfoFormat(&childrenBuf, &def->info, flags) < 0) {
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 4b437b440c6a4842e8c9fcf95a49372d0c0d9836..4eb7742887e7a25cc1ca5ebbc637f29e555bd6bf 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -1560,7 +1560,7 @@ enum {
 struct _virDomainMemballoonDef {
     int model;
     virDomainDeviceInfo info;
-    unsigned int period; /* seconds between collections */
+    int period; /* seconds between collections */
 };
 
 struct _virDomainNVRAMDef {
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 5bb7e5b390d8d3f8e104cc34adf2a6ec82f92acd..ae315df09e0570a2800ac97e433ee1893a9404ce 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -4309,7 +4309,7 @@ int qemuProcessStart(virConnectPtr conn,
     virCommandPtr cmd = NULL;
     struct qemuProcessHookData hookData;
     unsigned long cur_balloon;
-    unsigned int period = 0;
+    int period = 0;
     size_t i;
     bool rawio_set = false;
     char *nodeset = NULL;