diff --git a/components/style/cbindgen.toml b/components/style/cbindgen.toml
index e93d2c35c35..3b5d56f9882 100644
--- a/components/style/cbindgen.toml
+++ b/components/style/cbindgen.toml
@@ -59,5 +59,10 @@ include = [
   "PathCommand",
   "UnicodeRange",
   "UserSelect",
+  "Float",
+  "OverscrollBehavior",
+  "ScrollSnapType",
+  "OverflowClipBox",
+  "Resize",
 ]
 item_types = ["enums", "structs", "typedefs"]
diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index de6a84cccf2..6381bc1f47e 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -1389,8 +1389,14 @@ impl Clone for ${style_struct.gecko_struct_name} {
 
     # Types used with predefined_type()-defined properties that we can auto-generate.
     predefined_types = {
+        "Appearance": impl_simple,
+        "OverscrollBehavior": impl_simple,
+        "OverflowClipBox": impl_simple,
+        "ScrollSnapType": impl_simple,
+        "Float": impl_simple,
         "BreakBetween": impl_simple,
         "BreakWithin": impl_simple,
+        "Resize": impl_simple,
         "Color": impl_color,
         "ColorOrAuto": impl_color,
         "GreaterThanOrEqualToOneNumber": impl_simple,
@@ -3005,20 +3011,18 @@ fn static_assert() {
     }
 </%def>
 
-<% skip_box_longhands= """display -moz-appearance overflow-y vertical-align
+<% skip_box_longhands= """display overflow-y vertical-align
                           animation-name animation-delay animation-duration
                           animation-direction animation-fill-mode animation-play-state
                           animation-iteration-count animation-timing-function
-                          transition-duration transition-delay
+                          clear transition-duration transition-delay
                           transition-timing-function transition-property
                           rotate scroll-snap-points-x scroll-snap-points-y
-                          scroll-snap-type-x scroll-snap-type-y scroll-snap-coordinate
+                          scroll-snap-coordinate
                           perspective-origin -moz-binding will-change
-                          offset-path overscroll-behavior-x overscroll-behavior-y
-                          overflow-clip-box-inline overflow-clip-box-block
-                          perspective-origin -moz-binding will-change
-                          shape-outside contain touch-action translate
-                          scale""" %>
+                          offset-path perspective-origin -moz-binding
+                          will-change shape-outside contain touch-action
+                          translate scale""" %>
 <%self:impl_trait style_struct_name="Box" skip_longhands="${skip_box_longhands}">
     #[inline]
     pub fn set_display(&mut self, v: longhands::display::computed_value::T) {
@@ -3051,11 +3055,6 @@ fn static_assert() {
         self.gecko.mDisplay
     }
 
-    ${impl_simple('_moz_appearance', 'mAppearance')}
-
-    <% float_keyword = Keyword("float", "Left Right None", gecko_enum_prefix="StyleFloat") %>
-    ${impl_keyword('float', 'mFloat', float_keyword)}
-
     <% clear_keyword = Keyword(
         "clear",
         "Left Right None Both",
@@ -3064,9 +3063,6 @@ fn static_assert() {
     ) %>
     ${impl_keyword('clear', 'mBreakType', clear_keyword)}
 
-    <% resize_keyword = Keyword("resize", "None Both Horizontal Vertical") %>
-    ${impl_keyword('resize', 'mResize', resize_keyword)}
-
     <% overflow_x = data.longhands_by_name["overflow-x"] %>
     pub fn set_overflow_y(&mut self, v: longhands::overflow_y::computed_value::T) {
         use crate::properties::longhands::overflow_x::computed_value::T as BaseType;
@@ -3398,19 +3394,6 @@ fn static_assert() {
 
     ${impl_animation_timing_function()}
 
-    <% scroll_snap_type_keyword = Keyword("scroll-snap-type", "None Mandatory Proximity") %>
-    ${impl_keyword('scroll_snap_type_y', 'mScrollSnapTypeY', scroll_snap_type_keyword)}
-    ${impl_keyword('scroll_snap_type_x', 'mScrollSnapTypeX', scroll_snap_type_keyword)}
-
-    <% overscroll_behavior_keyword = Keyword("overscroll-behavior", "Auto Contain None",
-                                             gecko_enum_prefix="StyleOverscrollBehavior") %>
-    ${impl_keyword('overscroll_behavior_x', 'mOverscrollBehaviorX', overscroll_behavior_keyword)}
-    ${impl_keyword('overscroll_behavior_y', 'mOverscrollBehaviorY', overscroll_behavior_keyword)}
-
-    <% overflow_clip_box_keyword = Keyword("overflow-clip-box", "padding-box content-box") %>
-    ${impl_keyword('overflow_clip_box_inline', 'mOverflowClipBoxInline', overflow_clip_box_keyword)}
-    ${impl_keyword('overflow_clip_box_block', 'mOverflowClipBoxBlock', overflow_clip_box_keyword)}
-
     pub fn set_perspective_origin(&mut self, v: longhands::perspective_origin::computed_value::T) {
         self.gecko.mPerspectiveOrigin[0].set(v.horizontal);
         self.gecko.mPerspectiveOrigin[1].set(v.vertical);
diff --git a/components/style/properties/longhands/box.mako.rs b/components/style/properties/longhands/box.mako.rs
index 5a0f893cc63..f0bf6b0bcdb 100644
--- a/components/style/properties/longhands/box.mako.rs
+++ b/components/style/properties/longhands/box.mako.rs
@@ -574,6 +574,7 @@ ${helpers.predefined_type(
     alias="-webkit-appearance:layout.css.webkit-appearance.enabled",
     spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/-moz-appearance)",
     animation_value_type="discrete",
+    gecko_ffi_name="mAppearance",
 )}
 
 ${helpers.predefined_type(
diff --git a/components/style/values/computed/box.rs b/components/style/values/computed/box.rs
index 05d61015765..9ba38f04015 100644
--- a/components/style/values/computed/box.rs
+++ b/components/style/values/computed/box.rs
@@ -39,6 +39,7 @@ pub type Perspective = GenericPerspective<NonNegativeLength>;
 #[derive(
     Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss,
 )]
+#[repr(u8)]
 /// A computed value for the `float` property.
 pub enum Float {
     Left,
@@ -157,6 +158,7 @@ impl ToComputedValue for SpecifiedClear {
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, ToCss)]
+#[repr(u8)]
 pub enum Resize {
     None,
     Both,
diff --git a/components/style/values/specified/box.rs b/components/style/values/specified/box.rs
index 78f29ccf6de..84cbe9e879c 100644
--- a/components/style/values/specified/box.rs
+++ b/components/style/values/specified/box.rs
@@ -389,6 +389,7 @@ impl Parse for AnimationName {
     ToComputedValue,
     ToCss,
 )]
+#[repr(u8)]
 pub enum ScrollSnapType {
     None,
     Mandatory,
@@ -409,6 +410,7 @@ pub enum ScrollSnapType {
     ToComputedValue,
     ToCss,
 )]
+#[repr(u8)]
 pub enum OverscrollBehavior {
     Auto,
     Contain,
@@ -429,6 +431,7 @@ pub enum OverscrollBehavior {
     ToComputedValue,
     ToCss,
 )]
+#[repr(u8)]
 pub enum OverflowClipBox {
     PaddingBox,
     ContentBox,