diff --git a/Cargo.lock b/Cargo.lock
index 58fa1df1a34b..185f28e14a4b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1378,7 +1378,7 @@ dependencies = [
 name = "dom"
 version = "0.1.0"
 dependencies = [
- "bitflags 1.3.2",
+ "bitflags 2.999.999",
 ]
 
 [[package]]
@@ -4622,7 +4622,7 @@ dependencies = [
 name = "selectors"
 version = "0.22.0"
 dependencies = [
- "bitflags 1.3.2",
+ "bitflags 2.999.999",
  "cssparser",
  "derive_more",
  "fxhash",
@@ -4981,7 +4981,7 @@ dependencies = [
  "arrayvec",
  "atomic_refcell",
  "bindgen 0.64.0",
- "bitflags 1.3.2",
+ "bitflags 2.999.999",
  "byteorder",
  "cssparser",
  "derive_more",
@@ -5047,7 +5047,7 @@ name = "style_traits"
 version = "0.0.1"
 dependencies = [
  "app_units",
- "bitflags 1.3.2",
+ "bitflags 2.999.999",
  "cssparser",
  "euclid",
  "lazy_static",
diff --git a/dom/base/rust/Cargo.toml b/dom/base/rust/Cargo.toml
index efc42a2df573..38828c3f0f8e 100644
--- a/dom/base/rust/Cargo.toml
+++ b/dom/base/rust/Cargo.toml
@@ -11,4 +11,4 @@ license = "MPL-2.0"
 path = "lib.rs"
 
 [dependencies]
-bitflags = "1.0"
+bitflags = "2"
diff --git a/dom/base/rust/lib.rs b/dom/base/rust/lib.rs
index e40ea585f906..388c1320df51 100644
--- a/dom/base/rust/lib.rs
+++ b/dom/base/rust/lib.rs
@@ -9,6 +9,7 @@ use bitflags::bitflags;
 bitflags! {
     /// Event-based element states.
     #[repr(C)]
+    #[derive(Clone, Copy, Eq, PartialEq)]
     pub struct ElementState: u64 {
         /// The mouse is down on this element.
         /// <https://html.spec.whatwg.org/multipage/#selector-active>
@@ -181,6 +182,7 @@ bitflags! {
 bitflags! {
     /// Event-based document states.
     #[repr(C)]
+    #[derive(Clone, Copy, Eq, PartialEq)]
     pub struct DocumentState: u64 {
         /// Window activation status
         const WINDOW_INACTIVE = 1 << 0;
diff --git a/servo/components/selectors/Cargo.toml b/servo/components/selectors/Cargo.toml
index 1c87025b8920..ee78103cd4e7 100644
--- a/servo/components/selectors/Cargo.toml
+++ b/servo/components/selectors/Cargo.toml
@@ -18,7 +18,7 @@ path = "lib.rs"
 bench = []
 
 [dependencies]
-bitflags = "1.0"
+bitflags = "2"
 matches = "0.1"
 cssparser = "0.31"
 derive_more = { version = "0.99", default-features = false, features = ["add", "add_assign"] }
diff --git a/servo/components/selectors/builder.rs b/servo/components/selectors/builder.rs
index 410984619b18..d2bbf2c0c947 100644
--- a/servo/components/selectors/builder.rs
+++ b/servo/components/selectors/builder.rs
@@ -178,7 +178,7 @@ fn split_from_end<T>(s: &[T], at: usize) -> (&[T], &[T]) {
 
 bitflags! {
     /// Flags that indicate at which point of parsing a selector are we.
-    #[derive(Default, ToShmem)]
+    #[derive(Clone, Copy, Debug, Default, Eq, PartialEq, ToShmem)]
     pub (crate) struct SelectorFlags : u8 {
         const HAS_PSEUDO = 1 << 0;
         const HAS_SLOTTED = 1 << 1;
diff --git a/servo/components/selectors/matching.rs b/servo/components/selectors/matching.rs
index 5d44a5208862..707b88bd2f35 100644
--- a/servo/components/selectors/matching.rs
+++ b/servo/components/selectors/matching.rs
@@ -28,6 +28,7 @@ pub static RECOMMENDED_SELECTOR_BLOOM_FILTER_SIZE: usize = 4096;
 bitflags! {
     /// Set of flags that are set on either the element or its parent (depending
     /// on the flag) if the element could potentially match a selector.
+    #[derive(Clone, Copy)]
     pub struct ElementSelectorFlags: usize {
         /// When a child is added or removed from the parent, all the children
         /// must be restyled, because they may match :nth-last-child,
diff --git a/servo/components/selectors/parser.rs b/servo/components/selectors/parser.rs
index 4c1281c2cef1..c2a1bfeae57e 100644
--- a/servo/components/selectors/parser.rs
+++ b/servo/components/selectors/parser.rs
@@ -78,6 +78,7 @@ fn to_ascii_lowercase(s: &str) -> Cow<str> {
 
 bitflags! {
     /// Flags that indicate at which point of parsing a selector are we.
+    #[derive(Copy, Clone)]
     struct SelectorParsingState: u8 {
         /// Whether we should avoid adding default namespaces to selectors that
         /// aren't type or universal selectors.
@@ -1506,6 +1507,7 @@ pub struct RelativeSelector<Impl: SelectorImpl> {
 
 bitflags! {
     /// Composition of combinators in a given selector, not traversing selectors of pseudoclasses.
+    #[derive(Clone, Debug, Eq, PartialEq)]
     struct CombinatorComposition: u8 {
         const DESCENDANTS = 1 << 0;
         const SIBLINGS = 1 << 1;
@@ -1518,10 +1520,10 @@ impl CombinatorComposition {
         for combinator in CombinatorIter::new(inner_selector.iter_skip_relative_selector_anchor()) {
             match combinator {
                 Combinator::Descendant | Combinator::Child => {
-                    result.insert(CombinatorComposition::DESCENDANTS);
+                    result.insert(Self::DESCENDANTS);
                 },
                 Combinator::NextSibling | Combinator::LaterSibling => {
-                    result.insert(CombinatorComposition::SIBLINGS);
+                    result.insert(Self::SIBLINGS);
                 },
                 Combinator::Part | Combinator::PseudoElement | Combinator::SlotAssignment => {
                     continue
diff --git a/servo/components/selectors/visitor.rs b/servo/components/selectors/visitor.rs
index 785c12813a6b..69d66630e5b1 100644
--- a/servo/components/selectors/visitor.rs
+++ b/servo/components/selectors/visitor.rs
@@ -62,7 +62,7 @@ pub trait SelectorVisitor: Sized {
 
 bitflags! {
     /// The kinds of components the visitor is visiting the selector list of, if any
-    #[derive(Default)]
+    #[derive(Clone, Copy, Default)]
     pub struct SelectorListKind: u8 {
         /// The visitor is inside :not(..)
         const NEGATION = 1 << 0;
diff --git a/servo/components/style/Cargo.toml b/servo/components/style/Cargo.toml
index cb91e00c31e5..30ad42f6c460 100644
--- a/servo/components/style/Cargo.toml
+++ b/servo/components/style/Cargo.toml
@@ -30,7 +30,7 @@ gecko_refcount_logging = []
 app_units = "0.7"
 arrayvec = "0.7"
 atomic_refcell = "0.1"
-bitflags = "1.0"
+bitflags = "2"
 byteorder = "1.0"
 cssparser = "0.31"
 derive_more = { version = "0.99", default-features = false, features = ["add", "add_assign", "deref", "from"] }
diff --git a/servo/components/style/color/mod.rs b/servo/components/style/color/mod.rs
index f5a36aba2e88..f8ceee9703d2 100644
--- a/servo/components/style/color/mod.rs
+++ b/servo/components/style/color/mod.rs
@@ -128,7 +128,7 @@ impl ColorSpace {
 
 bitflags! {
     /// Flags used when serializing colors.
-    #[derive(Default, MallocSizeOf, ToShmem)]
+    #[derive(Clone, Copy, Default, MallocSizeOf, PartialEq, ToShmem)]
     #[repr(C)]
     pub struct ColorFlags : u8 {
         /// If set, serializes sRGB colors into `color(srgb ...)` instead of
diff --git a/servo/components/style/font_face.rs b/servo/components/style/font_face.rs
index 1f624e5d2a9b..ffa40cd74a54 100644
--- a/servo/components/style/font_face.rs
+++ b/servo/components/style/font_face.rs
@@ -97,7 +97,7 @@ pub enum FontFaceSourceFormatKeyword {
 bitflags! {
     /// Flags for the @font-face tech() function, indicating font technologies
     /// required by the resource.
-    #[derive(ToShmem)]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq, ToShmem)]
     #[repr(C)]
     pub struct FontFaceSourceTechFlags: u16 {
         /// Font requires OpenType feature support.
diff --git a/servo/components/style/gecko/selector_parser.rs b/servo/components/style/gecko/selector_parser.rs
index 9be8bf6623d3..6bf527b141a6 100644
--- a/servo/components/style/gecko/selector_parser.rs
+++ b/servo/components/style/gecko/selector_parser.rs
@@ -26,6 +26,7 @@ pub use crate::gecko::snapshot::SnapshotMap;
 
 bitflags! {
     // See NonTSPseudoClass::is_enabled_in()
+    #[derive(Copy, Clone)]
     struct NonTSPseudoClassFlag: u8 {
         const PSEUDO_CLASS_ENABLED_IN_UA_SHEETS = 1 << 0;
         const PSEUDO_CLASS_ENABLED_IN_CHROME = 1 << 1;
diff --git a/servo/components/style/gecko/snapshot.rs b/servo/components/style/gecko/snapshot.rs
index 84756406ed81..cb5f2dea676d 100644
--- a/servo/components/style/gecko/snapshot.rs
+++ b/servo/components/style/gecko/snapshot.rs
@@ -170,7 +170,7 @@ impl ElementSnapshot for GeckoElementSnapshot {
 
     fn state(&self) -> Option<ElementState> {
         if self.has_any(Flags::State) {
-            Some(ElementState::from_bits_truncate(self.mState))
+            Some(ElementState::from_bits_retain(self.mState))
         } else {
             None
         }
diff --git a/servo/components/style/gecko/wrapper.rs b/servo/components/style/gecko/wrapper.rs
index eb3ab03c73c7..b33f230d275f 100644
--- a/servo/components/style/gecko/wrapper.rs
+++ b/servo/components/style/gecko/wrapper.rs
@@ -719,7 +719,7 @@ impl<'le> GeckoElement<'le> {
 
     #[inline]
     fn document_state(&self) -> DocumentState {
-        DocumentState::from_bits_truncate(self.as_node().owner_doc().0.mDocumentState.bits)
+        DocumentState::from_bits_retain(self.as_node().owner_doc().0.mDocumentState.bits)
     }
 
     #[inline]
@@ -1183,7 +1183,7 @@ impl<'le> TElement for GeckoElement<'le> {
 
     #[inline]
     fn state(&self) -> ElementState {
-        ElementState::from_bits_truncate(self.state_internal())
+        ElementState::from_bits_retain(self.state_internal())
     }
 
     #[inline]
diff --git a/servo/components/style/gecko_bindings/sugar/origin_flags.rs b/servo/components/style/gecko_bindings/sugar/origin_flags.rs
index e0f0981c5d80..b27060405a43 100644
--- a/servo/components/style/gecko_bindings/sugar/origin_flags.rs
+++ b/servo/components/style/gecko_bindings/sugar/origin_flags.rs
@@ -20,7 +20,7 @@ pub fn assert_flags_match() {
 
 impl From<OriginFlags> for OriginSet {
     fn from(flags: OriginFlags) -> Self {
-        Self::from_bits_truncate(flags.0)
+        Self::from_bits_retain(flags.0)
     }
 }
 
diff --git a/servo/components/style/invalidation/element/restyle_hints.rs b/servo/components/style/invalidation/element/restyle_hints.rs
index 6020e429ec65..ccce71b7de35 100644
--- a/servo/components/style/invalidation/element/restyle_hints.rs
+++ b/servo/components/style/invalidation/element/restyle_hints.rs
@@ -9,6 +9,7 @@ use crate::traversal_flags::TraversalFlags;
 bitflags! {
     /// The kind of restyle we need to do for a given element.
     #[repr(C)]
+    #[derive(Clone, Copy, Debug)]
     pub struct RestyleHint: u16 {
         /// Do a selector match of the element.
         const RESTYLE_SELF = 1 << 0;
diff --git a/servo/components/style/logical_geometry.rs b/servo/components/style/logical_geometry.rs
index d475e9bdfc41..b8a7927dbb02 100644
--- a/servo/components/style/logical_geometry.rs
+++ b/servo/components/style/logical_geometry.rs
@@ -25,7 +25,7 @@ pub enum InlineBaseDirection {
 
 // TODO: improve the readability of the WritingMode serialization, refer to the Debug:fmt()
 bitflags!(
-    #[cfg_attr(feature = "servo", derive(MallocSizeOf, Serialize))]
+    #[derive(Clone, Copy, Eq, MallocSizeOf, PartialEq, Serialize)]
     #[repr(C)]
     pub struct WritingMode: u8 {
         /// A vertical writing mode; writing-mode is vertical-rl,
@@ -170,7 +170,7 @@ impl WritingMode {
 
     /// Returns the `horizontal-tb` value.
     pub fn horizontal_tb() -> Self {
-        Self::from_bits_truncate(0)
+        Self::empty()
     }
 
     #[inline]
@@ -418,7 +418,7 @@ impl DebugWritingMode {
 
     #[inline]
     fn new(mode: WritingMode) -> DebugWritingMode {
-        DebugWritingMode { mode: mode }
+        DebugWritingMode { mode }
     }
 }
 
diff --git a/servo/components/style/properties/computed_value_flags.rs b/servo/components/style/properties/computed_value_flags.rs
index d84311de0844..5fbe8f3a95e4 100644
--- a/servo/components/style/properties/computed_value_flags.rs
+++ b/servo/components/style/properties/computed_value_flags.rs
@@ -12,6 +12,7 @@ bitflags! {
     /// If we ever want to add some flags that shouldn't inherit for them,
     /// we might want to add a function to handle this.
     #[repr(C)]
+    #[derive(Clone, Copy, Eq, PartialEq)]
     pub struct ComputedValueFlags: u32 {
         /// Whether the style or any of the ancestors has a text-decoration-line
         /// property that should get propagated to descendants.
diff --git a/servo/components/style/properties/longhands/position.mako.rs b/servo/components/style/properties/longhands/position.mako.rs
index 251767c71bc3..4c974ef9dccf 100644
--- a/servo/components/style/properties/longhands/position.mako.rs
+++ b/servo/components/style/properties/longhands/position.mako.rs
@@ -36,24 +36,6 @@
     )}
 % endfor
 
-#[cfg(feature = "gecko")]
-macro_rules! impl_align_conversions {
-    ($name: path) => {
-        impl From<u8> for $name {
-            fn from(bits: u8) -> $name {
-                $name(crate::values::specified::align::AlignFlags::from_bits(bits)
-                      .expect("bits contain valid flag"))
-            }
-        }
-
-        impl From<$name> for u8 {
-            fn from(v: $name) -> u8 {
-                v.0.bits()
-            }
-        }
-    };
-}
-
 ${helpers.predefined_type(
     "z-index",
     "ZIndex",
@@ -184,9 +166,6 @@ ${helpers.single_keyword(
         servo_restyle_damage="reflow",
     )}
 
-    #[cfg(feature = "gecko")]
-    impl_align_conversions!(crate::values::specified::align::AlignItems);
-
     ${helpers.predefined_type(
         "justify-items",
         "JustifyItems",
@@ -195,9 +174,6 @@ ${helpers.single_keyword(
         spec="https://drafts.csswg.org/css-align/#propdef-justify-items",
         animation_value_type="discrete",
     )}
-
-    #[cfg(feature = "gecko")]
-    impl_align_conversions!(crate::values::specified::align::JustifyItems);
 % endif
 
 // Flex item properties
@@ -258,9 +234,6 @@ ${helpers.predefined_type(
         spec="https://drafts.csswg.org/css-align/#justify-self-property",
         animation_value_type="discrete",
     )}
-
-    #[cfg(feature = "gecko")]
-    impl_align_conversions!(crate::values::specified::align::SelfAlignment);
 % endif
 
 // https://drafts.csswg.org/css-flexbox/#propdef-order
diff --git a/servo/components/style/properties/properties.mako.rs b/servo/components/style/properties/properties.mako.rs
index c4414364fc2b..c580fdbc9174 100644
--- a/servo/components/style/properties/properties.mako.rs
+++ b/servo/components/style/properties/properties.mako.rs
@@ -1198,6 +1198,7 @@ impl CSSWideKeyword {
 
 bitflags! {
     /// A set of flags for properties.
+    #[derive(Clone, Copy)]
     pub struct PropertyFlags: u16 {
         /// This longhand property applies to ::first-letter.
         const APPLIES_TO_FIRST_LETTER = 1 << 1;
@@ -1427,7 +1428,7 @@ impl LonghandId {
                 0,
             % endfor
         ];
-        PropertyFlags::from_bits_truncate(FLAGS[self as usize])
+        PropertyFlags::from_bits_retain(FLAGS[self as usize])
     }
 
     /// Returns true if the property is one that is ignored when document
@@ -1602,7 +1603,7 @@ impl ShorthandId {
                 0,
             % endfor
         ];
-        PropertyFlags::from_bits_truncate(FLAGS[self as usize])
+        PropertyFlags::from_bits_retain(FLAGS[self as usize])
     }
 
     /// Returns whether this property is a legacy shorthand.
diff --git a/servo/components/style/queries/feature.rs b/servo/components/style/queries/feature.rs
index 0a85d7a245fb..977634c27a90 100644
--- a/servo/components/style/queries/feature.rs
+++ b/servo/components/style/queries/feature.rs
@@ -104,7 +104,7 @@ macro_rules! keyword_evaluator {
 bitflags! {
     /// Different flags or toggles that change how a expression is parsed or
     /// evaluated.
-    #[derive(ToShmem)]
+    #[derive(Clone, Copy, ToShmem)]
     pub struct FeatureFlags : u8 {
         /// The feature should only be parsed in chrome and ua sheets.
         const CHROME_AND_UA_ONLY = 1 << 0;
diff --git a/servo/components/style/selector_map.rs b/servo/components/style/selector_map.rs
index 9f774b75b73d..ed56cb41e566 100644
--- a/servo/components/style/selector_map.rs
+++ b/servo/components/style/selector_map.rs
@@ -40,7 +40,7 @@ impl Default for PrecomputedHasher {
 ///
 /// We can avoid selector-matching those global rules for all elements without
 /// these pseudo-class states.
-const RARE_PSEUDO_CLASS_STATES: ElementState = ElementState::from_bits_truncate(
+const RARE_PSEUDO_CLASS_STATES: ElementState = ElementState::from_bits_retain(
     ElementState::FULLSCREEN.bits() |
         ElementState::VISITED_OR_UNVISITED.bits() |
         ElementState::URLTARGET.bits() |
diff --git a/servo/components/style/stylesheets/origin.rs b/servo/components/style/stylesheets/origin.rs
index 27ad3fa184a4..6f8f97b66102 100644
--- a/servo/components/style/stylesheets/origin.rs
+++ b/servo/components/style/stylesheets/origin.rs
@@ -58,7 +58,7 @@ impl Origin {
 
 bitflags! {
     /// A set of origins. This is equivalent to Gecko's OriginFlags.
-    #[derive(MallocSizeOf)]
+    #[derive(Clone, Copy, PartialEq, MallocSizeOf)]
     pub struct OriginSet: u8 {
         /// <https://drafts.csswg.org/css-cascade/#cascade-origin-user-agent>
         const ORIGIN_USER_AGENT = Origin::UserAgent as u8;
@@ -85,7 +85,7 @@ impl OriginSet {
 
 impl From<Origin> for OriginSet {
     fn from(origin: Origin) -> Self {
-        Self::from_bits_truncate(origin as u8)
+        Self::from_bits_retain(origin as u8)
     }
 }
 
diff --git a/servo/components/style/thread_state.rs b/servo/components/style/thread_state.rs
index 2a39feef4871..3dc5541e00bd 100644
--- a/servo/components/style/thread_state.rs
+++ b/servo/components/style/thread_state.rs
@@ -9,8 +9,9 @@
 
 use std::cell::RefCell;
 
-bitflags! {
+bitflags ! {
     /// A thread state flag, used for multiple assertions.
+    #[derive(Clone, Copy, Eq, PartialEq)]
     pub struct ThreadState: u32 {
         /// Whether we're in a script thread.
         const SCRIPT          = 0x01;
diff --git a/servo/components/style/traversal_flags.rs b/servo/components/style/traversal_flags.rs
index 0987230ed026..4bb8e1374a95 100644
--- a/servo/components/style/traversal_flags.rs
+++ b/servo/components/style/traversal_flags.rs
@@ -10,6 +10,7 @@
 
 bitflags! {
     /// Flags that control the traversal process.
+    #[derive(Clone, Copy, Eq, PartialEq)]
     pub struct TraversalFlags: u32 {
         /// Traverse only elements for animation restyles.
         const AnimationOnly = 1 << 0;
diff --git a/servo/components/style/values/specified/align.rs b/servo/components/style/values/specified/align.rs
index ebb6f6383402..f0d36fe01e43 100644
--- a/servo/components/style/values/specified/align.rs
+++ b/servo/components/style/values/specified/align.rs
@@ -13,7 +13,7 @@ use style_traits::{CssWriter, KeywordsCollectFn, ParseError, SpecifiedValueInfo,
 
 bitflags! {
     /// Constants shared by multiple CSS Box Alignment properties
-    #[derive(MallocSizeOf, ToComputedValue, ToResolvedValue, ToShmem)]
+    #[derive(Clone, Copy, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem)]
     #[repr(C)]
     pub struct AlignFlags: u8 {
         // Enumeration stored in the lower 5 bits:
diff --git a/servo/components/style/values/specified/box.rs b/servo/components/style/values/specified/box.rs
index 3decb2582bdc..7c6daf8eebf8 100644
--- a/servo/components/style/values/specified/box.rs
+++ b/servo/components/style/values/specified/box.rs
@@ -1001,7 +1001,7 @@ impl WillChange {
 
 bitflags! {
     /// The change bits that we care about.
-    #[derive(Default, MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
+    #[derive(Clone, Copy, Default, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
     #[repr(C)]
     pub struct WillChangeBits: u16 {
         /// Whether a property which can create a stacking context **on any
@@ -1112,7 +1112,7 @@ impl Parse for WillChange {
 
 bitflags! {
     /// Values for the `touch-action` property.
-    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem, Parse)]
+    #[derive(Clone, Copy, Eq, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
     #[css(bitflags(single = "none,auto,manipulation", mixed = "pan-x,pan-y,pinch-zoom"))]
     #[repr(C)]
     pub struct TouchAction: u8 {
@@ -1140,7 +1140,7 @@ impl TouchAction {
 }
 
 bitflags! {
-    #[derive(MallocSizeOf, Parse, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+    #[derive(Clone, Copy, Eq, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
     #[css(bitflags(single = "none,strict,content", mixed="size,layout,style,paint,inline-size", overlapping_bits))]
     #[repr(C)]
     /// Constants for contain: https://drafts.csswg.org/css-contain/#contain-property
@@ -1882,7 +1882,7 @@ impl Overflow {
 }
 
 bitflags! {
-    #[derive(MallocSizeOf, SpecifiedValueInfo, ToCss, ToComputedValue, ToResolvedValue, ToShmem, Parse)]
+    #[derive(Clone, Copy, Eq, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
     #[repr(C)]
     #[css(bitflags(single = "auto", mixed = "stable,both-edges", validate_mixed="Self::has_stable"))]
     /// Values for scrollbar-gutter:
diff --git a/servo/components/style/values/specified/calc.rs b/servo/components/style/values/specified/calc.rs
index dc5b83597a29..7351a61069a0 100644
--- a/servo/components/style/values/specified/calc.rs
+++ b/servo/components/style/values/specified/calc.rs
@@ -119,6 +119,7 @@ bitflags! {
     /// This is used as a hint for the parser to fast-reject invalid
     /// expressions. Numbers are always allowed because they multiply other
     /// units.
+    #[derive(Clone, Copy)]
     struct CalcUnits: u8 {
         const LENGTH = 1 << 0;
         const PERCENTAGE = 1 << 1;
diff --git a/servo/components/style/values/specified/color.rs b/servo/components/style/values/specified/color.rs
index 57e0cf203985..94568b7d9273 100644
--- a/servo/components/style/values/specified/color.rs
+++ b/servo/components/style/values/specified/color.rs
@@ -1011,7 +1011,7 @@ impl Parse for CaretColor {
 bitflags! {
     /// Various flags to represent the color-scheme property in an efficient
     /// way.
-    #[derive(Default, MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
+    #[derive(Clone, Copy, Default, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
     #[repr(C)]
     #[value_info(other_values = "light,dark,only")]
     pub struct ColorSchemeFlags: u8 {
diff --git a/servo/components/style/values/specified/font.rs b/servo/components/style/values/specified/font.rs
index 4a5eed5296f8..47dc2c5ae335 100644
--- a/servo/components/style/values/specified/font.rs
+++ b/servo/components/style/values/specified/font.rs
@@ -983,7 +983,7 @@ impl Parse for FontSize {
 }
 
 bitflags! {
-    #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
+    #[derive(Clone, Copy)]
     /// Flags of variant alternates in bit
     struct VariantAlternatesParsingFlags: u8 {
         /// None of variant alternates enabled
@@ -1208,7 +1208,7 @@ macro_rules! impl_variant_east_asian {
         )+
     } => {
         bitflags! {
-            #[derive(MallocSizeOf, ToComputedValue, ToResolvedValue, ToShmem)]
+            #[derive(Clone, Copy, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem)]
             /// Vairants for east asian variant
             pub struct FontVariantEastAsian: u16 {
                 /// None of the features
@@ -1379,7 +1379,7 @@ macro_rules! impl_variant_ligatures {
         )+
     } => {
         bitflags! {
-            #[derive(MallocSizeOf, ToComputedValue, ToResolvedValue, ToShmem)]
+            #[derive(Clone, Copy, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem)]
             /// Variants of ligatures
             pub struct FontVariantLigatures: u16 {
                 /// Specifies that common default features are enabled
@@ -1557,8 +1557,8 @@ macro_rules! impl_variant_numeric {
         )+
     } => {
         bitflags! {
-            #[derive(MallocSizeOf, ToComputedValue, ToResolvedValue, ToShmem)]
-            /// Vairants of numeric values
+            #[derive(Clone, Copy, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem)]
+            /// Variants of numeric values
             pub struct FontVariantNumeric: u8 {
                 /// None of other variants are enabled.
                 const NORMAL = 0;
diff --git a/servo/components/style/values/specified/image.rs b/servo/components/style/values/specified/image.rs
index 72be1fed4610..9a6707066ed3 100644
--- a/servo/components/style/values/specified/image.rs
+++ b/servo/components/style/values/specified/image.rs
@@ -166,6 +166,7 @@ pub type MozImageRect = generic::GenericMozImageRect<NumberOrPercentage, Specifi
 pub enum MozImageRect {}
 
 bitflags! {
+    #[derive(Clone, Copy)]
     struct ParseImageFlags: u8 {
         const FORBID_NONE = 1 << 0;
         const FORBID_IMAGE_SET = 1 << 1;
diff --git a/servo/components/style/values/specified/position.rs b/servo/components/style/values/specified/position.rs
index 06456a312fc5..1f9134621d4e 100644
--- a/servo/components/style/values/specified/position.rs
+++ b/servo/components/style/values/specified/position.rs
@@ -370,15 +370,9 @@ impl Side for VerticalPositionKeyword {
 }
 
 bitflags! {
-    /// Controls how the auto-placement algorithm works
-    /// specifying exactly how auto-placed items get flowed into the grid
-    #[derive(
-        MallocSizeOf,
-        SpecifiedValueInfo,
-        ToComputedValue,
-        ToResolvedValue,
-        ToShmem
-    )]
+    /// Controls how the auto-placement algorithm works specifying exactly how auto-placed items
+    /// get flowed into the grid.
+    #[derive(Clone, Copy, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
     #[value_info(other_values = "row,column,dense")]
     #[repr(C)]
     pub struct GridAutoFlow: u8 {
diff --git a/servo/components/style/values/specified/svg.rs b/servo/components/style/values/specified/svg.rs
index 24b7d3f3aecc..ccdef24e4ed4 100644
--- a/servo/components/style/values/specified/svg.rs
+++ b/servo/components/style/values/specified/svg.rs
@@ -249,7 +249,7 @@ impl ToCss for SVGPaintOrder {
 
 bitflags! {
     /// The context properties we understand.
-    #[derive(Default, MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
+    #[derive(Clone, Copy, Eq, Default, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
     #[repr(C)]
     pub struct ContextPropertyBits: u8 {
         /// `fill`
diff --git a/servo/components/style/values/specified/text.rs b/servo/components/style/values/specified/text.rs
index 6912cc72a2d7..60eedb78723a 100644
--- a/servo/components/style/values/specified/text.rs
+++ b/servo/components/style/values/specified/text.rs
@@ -232,7 +232,7 @@ impl ToComputedValue for TextOverflow {
 }
 
 bitflags! {
-    #[derive(MallocSizeOf, Parse, Serialize, SpecifiedValueInfo, ToCss, ToComputedValue, ToResolvedValue, ToShmem)]
+    #[derive(Clone, Copy, Eq, MallocSizeOf, PartialEq, Parse, Serialize, SpecifiedValueInfo, ToCss, ToComputedValue, ToResolvedValue, ToShmem)]
     #[css(bitflags(single = "none", mixed = "underline,overline,line-through,blink"))]
     #[repr(C)]
     /// Specified keyword values for the text-decoration-line property.
@@ -408,8 +408,8 @@ pub enum TextTransformCase {
 }
 
 bitflags! {
-    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
-    #[value_info(other_values = "none,full-width,full-size-kana")]
+    #[derive(Clone, Copy, Eq, MallocSizeOf, PartialEq, Parse, Serialize, SpecifiedValueInfo, ToCss, ToComputedValue, ToResolvedValue, ToShmem)]
+    #[css(bitflags(mixed = "full-width,full-size-kana"))]
     #[repr(C)]
     /// Specified keyword values for non-case transforms in the text-transform property. (Non-exclusive.)
     pub struct TextTransformOther: u8 {
@@ -420,31 +420,6 @@ bitflags! {
     }
 }
 
-impl ToCss for TextTransformOther {
-    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
-    where
-        W: Write,
-    {
-        let mut writer = SequenceWriter::new(dest, " ");
-        let mut any = false;
-        macro_rules! maybe_write {
-            ($ident:ident => $str:expr) => {
-                if self.contains(TextTransformOther::$ident) {
-                    writer.raw_item($str)?;
-                    any = true;
-                }
-            };
-        }
-
-        maybe_write!(FULL_WIDTH => "full-width");
-        maybe_write!(FULL_SIZE_KANA => "full-size-kana");
-
-        debug_assert!(any || self.is_empty());
-
-        Ok(())
-    }
-}
-
 /// Specified and computed value of text-align-last.
 #[derive(
     Clone,
@@ -773,7 +748,7 @@ impl Parse for TextEmphasisStyle {
 }
 
 bitflags! {
-    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem, Parse, ToCss)]
+    #[derive(Clone, Copy, Eq, MallocSizeOf, PartialEq, Parse, Serialize, SpecifiedValueInfo, ToCss, ToComputedValue, ToResolvedValue, ToShmem)]
     #[repr(C)]
     #[css(bitflags(mixed="over,under,left,right", validate_mixed="Self::validate_and_simplify"))]
     /// Values for text-emphasis-position:
@@ -985,7 +960,7 @@ impl TextDecorationLength {
 }
 
 bitflags! {
-    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
+    #[derive(Clone, Copy, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
     #[value_info(other_values = "auto,from-font,under,left,right")]
     #[repr(C)]
     /// Specified keyword values for the text-underline-position property.
diff --git a/servo/components/style_traits/Cargo.toml b/servo/components/style_traits/Cargo.toml
index a4b6755362dd..fd50a5a0aaca 100644
--- a/servo/components/style_traits/Cargo.toml
+++ b/servo/components/style_traits/Cargo.toml
@@ -15,7 +15,7 @@ gecko = []
 
 [dependencies]
 app_units = "0.7"
-bitflags = "1.0"
+bitflags = "2"
 cssparser = "0.31"
 euclid = "0.22"
 lazy_static = "1"
diff --git a/servo/components/style_traits/lib.rs b/servo/components/style_traits/lib.rs
index 2f69f46873c6..054b74b6b81a 100644
--- a/servo/components/style_traits/lib.rs
+++ b/servo/components/style_traits/lib.rs
@@ -245,6 +245,7 @@ pub enum PropertySyntaxParseError {
 
 bitflags! {
     /// The mode to use when parsing values.
+    #[derive(Clone, Copy, Eq, PartialEq)]
     pub struct ParsingMode: u8 {
         /// In CSS; lengths must have units, except for zero values, where the unit can be omitted.
         /// <https://www.w3.org/TR/css3-values/#lengths>
diff --git a/servo/ports/geckolib/glue.rs b/servo/ports/geckolib/glue.rs
index 9dd2cc4087af..cfcb2b9adaf1 100644
--- a/servo/ports/geckolib/glue.rs
+++ b/servo/ports/geckolib/glue.rs
@@ -295,7 +295,7 @@ pub extern "C" fn Servo_TraverseSubtree(
     snapshots: *const ServoElementSnapshotTable,
     raw_flags: ServoTraversalFlags,
 ) -> bool {
-    let traversal_flags = TraversalFlags::from_bits_truncate(raw_flags);
+    let traversal_flags = TraversalFlags::from_bits_retain(raw_flags);
     debug_assert!(!snapshots.is_null());
 
     let element = GeckoElement(root);
@@ -4374,7 +4374,7 @@ fn parse_property_into(
     reporter: Option<&dyn ParseErrorReporter>,
 ) -> Result<(), ()> {
     let value = unsafe { value.as_str_unchecked() };
-    let parsing_mode = ParsingMode::from_bits_truncate(parsing_mode);
+    let parsing_mode = ParsingMode::from_bits_retain(parsing_mode);
 
     if let Some(non_custom) = property_id.non_custom_id() {
         if !non_custom.allowed_in_rule(rule_type.into()) {
@@ -5194,7 +5194,7 @@ pub extern "C" fn Servo_DeclarationBlock_SetKeywordValue(
         Clear => get_from_computed::<Clear>(value),
         VerticalAlign => VerticalAlign::Keyword(VerticalAlignKeyword::from_u32(value).unwrap()),
         TextAlign => get_from_computed::<TextAlign>(value),
-        TextEmphasisPosition => TextEmphasisPosition::from_bits_truncate(value as u8),
+        TextEmphasisPosition => TextEmphasisPosition::from_bits_retain(value as u8),
         FontSize => {
             // We rely on Gecko passing in font-size values (0...7) here.
             longhands::font_size::SpecifiedValue::from_html_size(value as u8)
@@ -6754,7 +6754,7 @@ pub extern "C" fn Servo_StyleSet_HasStateDependency(
 ) -> bool {
     let element = GeckoElement(element);
 
-    let state = ElementState::from_bits_truncate(state);
+    let state = ElementState::from_bits_retain(state);
     let data = raw_data.borrow();
 
     data.stylist
@@ -6769,7 +6769,7 @@ pub extern "C" fn Servo_StyleSet_HasNthOfStateDependency(
 ) -> bool {
     let element = GeckoElement(element);
 
-    let state = ElementState::from_bits_truncate(state);
+    let state = ElementState::from_bits_retain(state);
     let data = raw_data.borrow();
 
     data.stylist
@@ -6781,7 +6781,7 @@ pub extern "C" fn Servo_StyleSet_HasDocumentStateDependency(
     raw_data: &PerDocumentStyleData,
     state: u64,
 ) -> bool {
-    let state = DocumentState::from_bits_truncate(state);
+    let state = DocumentState::from_bits_retain(state);
     let data = raw_data.borrow();
 
     data.stylist.has_document_state_dependency(state)
@@ -7360,7 +7360,7 @@ pub unsafe extern "C" fn Servo_InvalidateStyleForDocStateChanges(
     let root = GeckoElement(root);
     let mut processor = DocumentStateInvalidationProcessor::new(
         iter,
-        DocumentState::from_bits_truncate(states_changed),
+        DocumentState::from_bits_retain(states_changed),
         &mut nth_index_cache,
         root.as_node().owner_doc().quirks_mode(),
     );