diff --git a/tests/cli-test-xml/compare/virt-install-singleton-config-2.xml b/tests/cli-test-xml/compare/virt-install-singleton-config-2.xml
index 839098f4..8f04436a 100644
--- a/tests/cli-test-xml/compare/virt-install-singleton-config-2.xml
+++ b/tests/cli-test-xml/compare/virt-install-singleton-config-2.xml
@@ -187,7 +187,9 @@
       <model type="qxl"/>
     </video>
     <watchdog model="ib700" action="pause"/>
-    <memballoon model="virtio"/>
+    <memballoon model="virtio">
+      <autodeflate>on</autodeflate>
+    </memballoon>
     <rng model="virtio">
       <backend model="egd" type="udp">
         <source mode="bind" host="127.0.0.1" service="8000"/>
@@ -399,7 +401,9 @@
       <model type="qxl"/>
     </video>
     <watchdog model="ib700" action="pause"/>
-    <memballoon model="virtio"/>
+    <memballoon model="virtio">
+      <autodeflate>on</autodeflate>
+    </memballoon>
     <rng model="virtio">
       <backend model="egd" type="udp">
         <source mode="bind" host="127.0.0.1" service="8000"/>
diff --git a/tests/clitest.py b/tests/clitest.py
index 84d6ec90..9a71c9d6 100644
--- a/tests/clitest.py
+++ b/tests/clitest.py
@@ -508,7 +508,7 @@ cache.mode=emulate,cache.level=3
 --controller scsi,model=virtio-scsi
 --graphics vnc
 --filesystem /foo/source,/bar/target
---memballoon virtio
+--memballoon virtio,autodeflate=on
 --watchdog ib700,action=pause
 --tpm passthrough,model=tpm-crb,path=/dev/tpm0
 --rng egd,backend_host=127.0.0.1,backend_service=8000,backend_type=udp,backend_mode=bind,backend_connect_host=foo,backend_connect_service=708,rate.bytes=1234,rate.period=1000,model=virtio
diff --git a/virtinst/cli.py b/virtinst/cli.py
index 1899c600..715fc482 100644
--- a/virtinst/cli.py
+++ b/virtinst/cli.py
@@ -3502,6 +3502,7 @@ class ParserMemballoon(VirtCLIParser):
         _add_common_device_args(cls, virtio_options=True)
 
         cls.add_arg("model", "model")
+        cls.add_arg("autodeflate", "autodeflate", is_onoff=True)
 
 
 ###################
diff --git a/virtinst/devices/memballoon.py b/virtinst/devices/memballoon.py
index 5c3404b0..9a05b344 100644
--- a/virtinst/devices/memballoon.py
+++ b/virtinst/devices/memballoon.py
@@ -13,6 +13,7 @@ class DeviceMemballoon(Device):
     XML_NAME = "memballoon"
 
     model = XMLProperty("./@model")
+    autodeflate = XMLProperty("./autodeflate", is_onoff=True)
 
 
     ##################