diff --git a/buffet/dbus_bindings/org.chromium.Buffet.Command.xml b/buffet/dbus_bindings/org.chromium.Buffet.Command.xml
index 89481ec..c9ed924 100644
--- a/buffet/dbus_bindings/org.chromium.Buffet.Command.xml
+++ b/buffet/dbus_bindings/org.chromium.Buffet.Command.xml
@@ -3,7 +3,7 @@
 <node xmlns:tp="http://telepathy.freedesktop.org/wiki/DbusSpec#extensions-v0">
   <interface name="org.chromium.Buffet.Command">
     <method name="SetProgress">
-      <arg name="progress" type="i" direction="in"/>
+      <arg name="progress" type="a{sv}" direction="in"/>
       <annotation name="org.chromium.DBus.Method.Kind" value="normal"/>
     </method>
     <method name="SetResults">
@@ -34,8 +34,8 @@
     <property name="Category" type="s" access="read"/>
     <property name="Id" type="s" access="read"/>
     <property name="Status" type="s" access="read"/>
-    <property name="Progress" type="i" access="read"/>
     <property name="Parameters" type="a{sv}" access="read"/>
+    <property name="Progress" type="a{sv}" access="read"/>
     <property name="Results" type="a{sv}" access="read"/>
     <property name="Origin" type="s" access="read">
       <tp:docstring>