--- a/servo/components/style/properties/longhand/ui.mako.rs
+++ b/servo/components/style/properties/longhand/ui.mako.rs
@@ -23,23 +23,25 @@
                          gecko_ffi_name="mUserSelect",
                          gecko_enum_prefix="StyleUserSelect",
                          animation_value_type="none",
                          spec="https://drafts.csswg.org/css-ui-4/#propdef-user-select")}
 
 ${helpers.single_keyword("-moz-window-dragging", "default drag no-drag", products="gecko",
                          gecko_ffi_name="mWindowDragging",
                          gecko_enum_prefix="StyleWindowDragging",
-                         animation_value_type="none",
+                         gecko_inexhaustive=True,
+                         animation_value_type="discrete",
                          spec="None (Nonstandard Firefox-only property)")}
 
 ${helpers.single_keyword("-moz-window-shadow", "none default menu tooltip sheet", products="gecko",
                          gecko_ffi_name="mWindowShadow",
                          gecko_constant_prefix="NS_STYLE_WINDOW_SHADOW",
-                         animation_value_type="none",
+                         gecko_inexhaustive=True,
+                         animation_value_type="discrete",
                          internal=True,
                          spec="None (Nonstandard internal property)")}
 
 <%helpers:longhand name="-moz-force-broken-image-icon"
                    products="gecko"
                    animation_value_type="none"
                    spec="None (Nonstandard Firefox-only property)">
     use std::fmt;