--- a/servo/components/style/properties/longhand/ui.mako.rs
+++ b/servo/components/style/properties/longhand/ui.mako.rs
@@ -17,19 +17,20 @@
                          spec="https://drafts.csswg.org/css-ui/#input-method-editor")}
 
 ${helpers.single_keyword("-moz-user-select", "auto text none all element elements" +
                             " toggle tri-state -moz-all -moz-text",
                          products="gecko",
                          alias="-webkit-user-select",
                          gecko_ffi_name="mUserSelect",
                          gecko_enum_prefix="StyleUserSelect",
+                         gecko_inexhaustive=True,
                          gecko_strip_moz_prefix=False,
                          aliases="-moz-none=none",
-                         animation_value_type="none",
+                         animation_value_type="discrete",
                          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",
                          gecko_inexhaustive=True,
                          animation_value_type="discrete",
                          spec="None (Nonstandard Firefox-only property)")}