diff --git a/src/devkit-power-source.c b/src/devkit-power-source.c
index 9172c59..e90082c 100644
--- a/src/devkit-power-source.c
+++ b/src/devkit-power-source.c
@@ -68,7 +68,6 @@ struct DevkitPowerSourcePrivate
 
         double battery_energy;
         double battery_energy_empty;
-        double battery_energy_empty_design;
         double battery_energy_full;
         double battery_energy_full_design;
         double battery_energy_rate;
@@ -96,7 +95,6 @@ enum
         PROP_LINE_POWER_ONLINE,
         PROP_BATTERY_ENERGY,
         PROP_BATTERY_ENERGY_EMPTY,
-        PROP_BATTERY_ENERGY_EMPTY_DESIGN,
         PROP_BATTERY_ENERGY_FULL,
         PROP_BATTERY_ENERGY_FULL_DESIGN,
         PROP_BATTERY_ENERGY_RATE,
@@ -162,9 +160,6 @@ get_property (GObject         *object,
         case PROP_BATTERY_ENERGY_EMPTY:
                 g_value_set_double (value, source->priv->battery_energy_empty);
                 break;
-        case PROP_BATTERY_ENERGY_EMPTY_DESIGN:
-                g_value_set_double (value, source->priv->battery_energy_empty_design);
-                break;
         case PROP_BATTERY_ENERGY_FULL:
                 g_value_set_double (value, source->priv->battery_energy_full);
                 break;
@@ -258,10 +253,6 @@ devkit_power_source_class_init (DevkitPowerSourceClass *klass)
                 object_class,
                 PROP_BATTERY_ENERGY_EMPTY,
                 g_param_spec_double ("battery-energy-empty", NULL, NULL, 0, G_MAXDOUBLE, 0, G_PARAM_READABLE));
-        g_object_class_install_property (
-                object_class,
-                PROP_BATTERY_ENERGY_EMPTY_DESIGN,
-                g_param_spec_double ("battery-energy-empty-design", NULL, NULL, 0, G_MAXDOUBLE, 0, G_PARAM_READABLE));
         g_object_class_install_property (
                 object_class,
                 PROP_BATTERY_ENERGY_FULL,
diff --git a/src/org.freedesktop.DeviceKit.Power.Source.xml b/src/org.freedesktop.DeviceKit.Power.Source.xml
index bcf164f..61edd16 100644
--- a/src/org.freedesktop.DeviceKit.Power.Source.xml
+++ b/src/org.freedesktop.DeviceKit.Power.Source.xml
@@ -128,17 +128,6 @@
       </doc:para></doc:description></doc:doc>
     </property>
 
-    <property name="battery-energy-empty-design" type="d" access="read">
-      <doc:doc><doc:description><doc:para>
-            Amount of energy (measured in Wh) the power source is
-            designed to hold when it's considered to be empty.
-          </doc:para><doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:type">type</doc:ref>
-            has the value "battery".
-      </doc:para></doc:description></doc:doc>
-    </property>
-
     <property name="battery-energy-full" type="d" access="read">
       <doc:doc><doc:description><doc:para>
             Amount of energy (measured in Wh) in the power source when