diff --git a/components/style/properties/longhand/xul.mako.rs b/components/style/properties/longhand/xul.mako.rs
index 4c9d6fd022a..34b3de89e0b 100644
--- a/components/style/properties/longhand/xul.mako.rs
+++ b/components/style/properties/longhand/xul.mako.rs
@@ -19,7 +19,8 @@ ${helpers.single_keyword("-moz-box-align", "stretch start center baseline end",
 ${helpers.single_keyword("-moz-box-direction", "normal reverse",
                          products="gecko", gecko_ffi_name="mBoxDirection",
                          gecko_enum_prefix="StyleBoxDirection",
-                         animation_value_type="none",
+                         gecko_inexhaustive=True,
+                         animation_value_type="discrete",
                          alias="-webkit-box-direction",
                          spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/box-direction)")}
 
@@ -33,21 +34,24 @@ ${helpers.single_keyword("-moz-box-orient", "horizontal vertical",
                          products="gecko", gecko_ffi_name="mBoxOrient",
                          extra_gecko_aliases="inline-axis=horizontal block-axis=vertical",
                          gecko_enum_prefix="StyleBoxOrient",
-                         animation_value_type="none",
+                         gecko_inexhaustive=True,
+                         animation_value_type="discrete",
                          alias="-webkit-box-orient",
                          spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/box-orient)")}
 
 ${helpers.single_keyword("-moz-box-pack", "start center end justify",
                          products="gecko", gecko_ffi_name="mBoxPack",
                          gecko_enum_prefix="StyleBoxPack",
-                         animation_value_type="none",
+                         gecko_inexhaustive=True,
+                         animation_value_type="discrete",
                          alias="-webkit-box-pack",
                          spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/box-pack)")}
 
 ${helpers.single_keyword("-moz-stack-sizing", "stretch-to-fit ignore ignore-horizontal ignore-vertical",
                          products="gecko", gecko_ffi_name="mStackSizing",
                          gecko_enum_prefix="StyleStackSizing",
-                         animation_value_type="none",
+                         gecko_inexhaustive=True,
+                         animation_value_type="discrete",
                          spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/-moz-stack-sizing)")}
 
 ${helpers.predefined_type("-moz-box-ordinal-group", "Integer", "0",