diff --git a/Cargo.lock b/Cargo.lock
index 71a1426d..707f8450 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -56,9 +56,9 @@ dependencies = [
  "accesskit",
  "accesskit_consumer",
  "hashbrown",
- "objc2",
- "objc2-app-kit",
- "objc2-foundation",
+ "objc2 0.6.0",
+ "objc2-app-kit 0.3.0",
+ "objc2-foundation 0.3.0",
 ]
 
 [[package]]
@@ -143,7 +143,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ef6978589202a00cd7e118380c448a08b6ed394c3a8df3a430d0898e3a42d046"
 dependencies = [
  "android-properties",
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "cc",
  "cesu8",
  "jni",
@@ -410,9 +410,9 @@ checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
 [[package]]
 name = "bitflags"
-version = "2.4.1"
+version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "327762f6e5a765692301e5bb513e0d9fef63be86bbc14528052b1cd3e6f03e07"
+checksum = "8f68f53c83ab957f72c32642f3868eec03eb974d1fb82e453128456482613d36"
 
 [[package]]
 name = "block-buffer"
@@ -429,7 +429,7 @@ version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "43ff7d91d3c1d568065b06c899777d1e48dcf76103a672a0adbc238a7f247f1e"
 dependencies = [
- "objc2",
+ "objc2 0.5.1",
 ]
 
 [[package]]
@@ -469,7 +469,7 @@ version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7b50b5a44d59a98c55a9eeb518f39bf7499ba19fd98ee7d22618687f3f10adbf"
 dependencies = [
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "log",
  "polling",
  "rustix",
@@ -1015,7 +1015,7 @@ version = "0.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3af92c55d7d839293953fcd0fda5ecfe93297cfde6ffbdec13b41d99c0ba6607"
 dependencies = [
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "libc",
  "redox_syscall 0.4.1",
 ]
@@ -1111,7 +1111,7 @@ version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c3f42e7bbe13d351b6bead8286a43aac9534b82bd3cc43e47037f012ebfd62d4"
 dependencies = [
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "jni-sys",
  "log",
  "ndk-sys",
@@ -1155,7 +1155,7 @@ version = "0.29.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "71e2746dc3a24dd78b3cfcb7be93368c6de9963d30f43a6a73998a9cf4b17b46"
 dependencies = [
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "cfg-if",
  "cfg_aliases",
  "libc",
@@ -1209,6 +1209,15 @@ dependencies = [
  "objc2-encode",
 ]
 
+[[package]]
+name = "objc2"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3531f65190d9cff863b77a99857e74c314dd16bf56c538c4b57c7cbc3f3a6e59"
+dependencies = [
+ "objc2-encode",
+]
+
 [[package]]
 name = "objc2-app-kit"
 version = "0.2.0"
@@ -1216,9 +1225,21 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fb79768a710a9a1798848179edb186d1af7e8a8679f369e4b8d201dd2a034047"
 dependencies = [
  "block2",
- "objc2",
+ "objc2 0.5.1",
  "objc2-core-data",
- "objc2-foundation",
+ "objc2-foundation 0.2.0",
+]
+
+[[package]]
+name = "objc2-app-kit"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5906f93257178e2f7ae069efb89fbd6ee94f0592740b5f8a1512ca498814d0fb"
+dependencies = [
+ "bitflags 2.8.0",
+ "objc2 0.6.0",
+ "objc2-core-foundation",
+ "objc2-foundation 0.3.0",
 ]
 
 [[package]]
@@ -1228,15 +1249,25 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6e092bc42eaf30a08844e6a076938c60751225ec81431ab89f5d1ccd9f958d6c"
 dependencies = [
  "block2",
- "objc2",
- "objc2-foundation",
+ "objc2 0.5.1",
+ "objc2-foundation 0.2.0",
+]
+
+[[package]]
+name = "objc2-core-foundation"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "daeaf60f25471d26948a1c2f840e3f7d86f4109e3af4e8e4b5cd70c39690d925"
+dependencies = [
+ "bitflags 2.8.0",
+ "objc2 0.6.0",
 ]
 
 [[package]]
 name = "objc2-encode"
-version = "4.0.1"
+version = "4.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "88658da63e4cc2c8adb1262902cd6af51094df0488b760d6fd27194269c0950a"
+checksum = "ef25abbcd74fb2609453eb695bd2f860d389e457f67dc17cafc8b8cbc89d0c33"
 
 [[package]]
 name = "objc2-foundation"
@@ -1246,7 +1277,18 @@ checksum = "cfaefe14254871ea16c7d88968c0ff14ba554712a20d76421eec52f0a7fb8904"
 dependencies = [
  "block2",
  "dispatch",
- "objc2",
+ "objc2 0.5.1",
+]
+
+[[package]]
+name = "objc2-foundation"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3a21c6c9014b82c39515db5b396f91645182611c97d24637cf56ac01e5f8d998"
+dependencies = [
+ "bitflags 2.8.0",
+ "objc2 0.6.0",
+ "objc2-core-foundation",
 ]
 
 [[package]]
@@ -1572,7 +1614,7 @@ version = "0.38.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2b426b0506e5d50a7d8dafcf2e81471400deb602392c7dd110815afb4eaf02a3"
 dependencies = [
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "errno",
  "libc",
  "linux-raw-sys",
@@ -1737,7 +1779,7 @@ version = "0.18.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "60e3d9941fa3bacf7c2bf4b065304faa14164151254cd16ce1b1bc8fc381600f"
 dependencies = [
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "calloop",
  "calloop-wayland-source",
  "cursor-icon",
@@ -2099,7 +2141,7 @@ version = "0.31.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1ca7d52347346f5473bf2f56705f360e8440873052e575e55890c4fa57843ed3"
 dependencies = [
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "nix 0.26.2",
  "wayland-backend",
  "wayland-scanner",
@@ -2111,7 +2153,7 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "625c5029dbd43d25e6aa9615e88b829a5cad13b2819c4ae129fdbb7c31ab4c7e"
 dependencies = [
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "cursor-icon",
  "wayland-backend",
 ]
@@ -2133,7 +2175,7 @@ version = "0.31.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e253d7107ba913923dc253967f35e8561a3c65f914543e46843c88ddd729e21c"
 dependencies = [
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "wayland-backend",
  "wayland-client",
  "wayland-scanner",
@@ -2145,7 +2187,7 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "23803551115ff9ea9bce586860c5c5a971e360825a0309264102a9495a5ff479"
 dependencies = [
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "wayland-backend",
  "wayland-client",
  "wayland-protocols",
@@ -2158,7 +2200,7 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ad1f61b76b6c2d8742e10f9ba5c3737f6530b4c243132c2a2ccc8aa96fe25cd6"
 dependencies = [
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "wayland-backend",
  "wayland-client",
  "wayland-protocols",
@@ -2526,7 +2568,7 @@ dependencies = [
  "ahash",
  "android-activity",
  "atomic-waker",
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "bytemuck",
  "calloop",
  "cfg_aliases",
@@ -2539,9 +2581,9 @@ dependencies = [
  "libc",
  "memmap2",
  "ndk",
- "objc2",
- "objc2-app-kit",
- "objc2-foundation",
+ "objc2 0.5.1",
+ "objc2-app-kit 0.2.0",
+ "objc2-foundation 0.2.0",
  "orbclient",
  "percent-encoding",
  "pin-project",
@@ -2634,7 +2676,7 @@ version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d039de8032a9a8856a6be89cea3e5d12fdd82306ab7c94d74e6deab2460651c5"
 dependencies = [
- "bitflags 2.4.1",
+ "bitflags 2.8.0",
  "dlib",
  "log",
  "once_cell",
diff --git a/platforms/macos/Cargo.toml b/platforms/macos/Cargo.toml
index 2af0abf6..2b6e5b21 100644
--- a/platforms/macos/Cargo.toml
+++ b/platforms/macos/Cargo.toml
@@ -18,14 +18,15 @@ default-target = "x86_64-apple-darwin"
 accesskit = { version = "0.17.1", path = "../../common" }
 accesskit_consumer = { version = "0.26.0", path = "../../consumer" }
 hashbrown = { version = "0.15", default-features = false, features = ["default-hasher"] }
-objc2 = "0.5.1"
-objc2-foundation = { version = "0.2.0", features = [
+objc2 = { version = "0.6", default-features = false }
+objc2-foundation = { version = "0.3", default-features = false, features = [
     "NSArray",
     "NSDictionary",
     "NSValue",
     "NSThread",
 ] }
-objc2-app-kit = { version = "0.2.0", features = [
+objc2-app-kit = { version = "0.3", default-features = false, features = [
+    "objc2-core-foundation",
     "NSAccessibility",
     "NSAccessibilityConstants",
     "NSAccessibilityElement",
diff --git a/platforms/macos/src/adapter.rs b/platforms/macos/src/adapter.rs
index 2bd942bb..54971890 100644
--- a/platforms/macos/src/adapter.rs
+++ b/platforms/macos/src/adapter.rs
@@ -8,7 +8,7 @@ use accesskit::{
     Tree as TreeData, TreeUpdate,
 };
 use accesskit_consumer::{FilterResult, Tree};
-use objc2::rc::{Id, WeakId};
+use objc2::rc::{Retained, Weak};
 use objc2_app_kit::NSView;
 use objc2_foundation::{MainThreadMarker, NSArray, NSObject, NSPoint};
 use std::{ffi::c_void, ptr::null_mut, rc::Rc};
@@ -25,7 +25,7 @@ const PLACEHOLDER_ROOT_ID: NodeId = NodeId(0);
 
 enum State {
     Inactive {
-        view: WeakId<NSView>,
+        view: Weak<NSView>,
         is_view_focused: bool,
         action_handler: Rc<dyn ActionHandlerNoMut>,
         mtm: MainThreadMarker,
@@ -62,8 +62,8 @@ impl Adapter {
         is_view_focused: bool,
         action_handler: impl 'static + ActionHandler,
     ) -> Self {
-        let view = unsafe { Id::retain(view as *mut NSView) }.unwrap();
-        let view = WeakId::from_id(&view);
+        let view = unsafe { Retained::retain(view as *mut NSView) }.unwrap();
+        let view = Weak::from_retained(&view);
         let mtm = MainThreadMarker::new().unwrap();
         let state = State::Inactive {
             view,
@@ -202,20 +202,22 @@ impl Adapter {
         let state = tree.state();
         let node = state.root();
         let platform_nodes = if filter(&node) == FilterResult::Include {
-            vec![Id::into_super(Id::into_super(
-                context.get_or_create_platform_node(node.id()),
-            ))]
+            vec![context
+                .get_or_create_platform_node(node.id())
+                .into_super()
+                .into_super()]
         } else {
             node.filtered_children(filter)
                 .map(|node| {
-                    Id::into_super(Id::into_super(
-                        context.get_or_create_platform_node(node.id()),
-                    ))
+                    context
+                        .get_or_create_platform_node(node.id())
+                        .into_super()
+                        .into_super()
                 })
-                .collect::<Vec<Id<NSObject>>>()
+                .collect::<Vec<Retained<NSObject>>>()
         };
-        let array = NSArray::from_vec(platform_nodes);
-        Id::autorelease_return(array)
+        let array = NSArray::from_retained_slice(&platform_nodes);
+        Retained::autorelease_return(array)
     }
 
     pub fn focus<H: ActivationHandler + ?Sized>(
@@ -227,14 +229,14 @@ impl Adapter {
         let state = tree.state();
         if let Some(node) = state.focus() {
             if can_be_focused(&node) {
-                return Id::autorelease_return(context.get_or_create_platform_node(node.id()))
+                return Retained::autorelease_return(context.get_or_create_platform_node(node.id()))
                     as *mut _;
             }
         }
         null_mut()
     }
 
-    fn weak_view(&self) -> &WeakId<NSView> {
+    fn weak_view(&self) -> &Weak<NSView> {
         match &self.state {
             State::Inactive { view, .. } => view,
             State::Placeholder {
@@ -263,6 +265,6 @@ impl Adapter {
         let root = state.root();
         let point = from_ns_point(&view, &root, point);
         let node = root.node_at_point(point, &filter).unwrap_or(root);
-        Id::autorelease_return(context.get_or_create_platform_node(node.id())) as *mut _
+        Retained::autorelease_return(context.get_or_create_platform_node(node.id())) as *mut _
     }
 }
diff --git a/platforms/macos/src/context.rs b/platforms/macos/src/context.rs
index ad4c3251..833fb776 100644
--- a/platforms/macos/src/context.rs
+++ b/platforms/macos/src/context.rs
@@ -6,7 +6,7 @@
 use accesskit::{ActionHandler, ActionRequest, NodeId};
 use accesskit_consumer::Tree;
 use hashbrown::HashMap;
-use objc2::rc::{Id, WeakId};
+use objc2::rc::{Retained, Weak};
 use objc2_app_kit::*;
 use objc2_foundation::MainThreadMarker;
 use std::{cell::RefCell, rc::Rc};
@@ -32,16 +32,16 @@ impl<H: ActionHandler> ActionHandlerNoMut for ActionHandlerWrapper<H> {
 }
 
 pub(crate) struct Context {
-    pub(crate) view: WeakId<NSView>,
+    pub(crate) view: Weak<NSView>,
     pub(crate) tree: RefCell<Tree>,
     pub(crate) action_handler: Rc<dyn ActionHandlerNoMut>,
-    platform_nodes: RefCell<HashMap<NodeId, Id<PlatformNode>>>,
+    platform_nodes: RefCell<HashMap<NodeId, Retained<PlatformNode>>>,
     pub(crate) mtm: MainThreadMarker,
 }
 
 impl Context {
     pub(crate) fn new(
-        view: WeakId<NSView>,
+        view: Weak<NSView>,
         tree: Tree,
         action_handler: Rc<dyn ActionHandlerNoMut>,
         mtm: MainThreadMarker,
@@ -55,7 +55,10 @@ impl Context {
         })
     }
 
-    pub(crate) fn get_or_create_platform_node(self: &Rc<Self>, id: NodeId) -> Id<PlatformNode> {
+    pub(crate) fn get_or_create_platform_node(
+        self: &Rc<Self>,
+        id: NodeId,
+    ) -> Retained<PlatformNode> {
         let mut platform_nodes = self.platform_nodes.borrow_mut();
         if let Some(result) = platform_nodes.get(&id) {
             return result.clone();
@@ -66,7 +69,7 @@ impl Context {
         result
     }
 
-    pub(crate) fn remove_platform_node(&self, id: NodeId) -> Option<Id<PlatformNode>> {
+    pub(crate) fn remove_platform_node(&self, id: NodeId) -> Option<Retained<PlatformNode>> {
         let mut platform_nodes = self.platform_nodes.borrow_mut();
         platform_nodes.remove(&id)
     }
diff --git a/platforms/macos/src/event.rs b/platforms/macos/src/event.rs
index 2bb851ea..15e0df2d 100644
--- a/platforms/macos/src/event.rs
+++ b/platforms/macos/src/event.rs
@@ -32,9 +32,9 @@ impl QueuedEvent {
         Self::Announcement {
             text: node.value().unwrap(),
             priority: if node.live() == Live::Assertive {
-                NSAccessibilityPriorityLevel::NSAccessibilityPriorityHigh
+                NSAccessibilityPriorityLevel::High
             } else {
-                NSAccessibilityPriorityLevel::NSAccessibilityPriorityMedium
+                NSAccessibilityPriorityLevel::Medium
             },
         }
     }
@@ -73,7 +73,7 @@ impl QueuedEvent {
                     }
                 };
 
-                let mut user_info = NSMutableDictionary::<_, AnyObject>::new();
+                let user_info = NSMutableDictionary::<_, AnyObject>::new();
                 let text = NSString::from_str(&text);
                 unsafe {
                     user_info.setObject_forKey(
diff --git a/platforms/macos/src/node.rs b/platforms/macos/src/node.rs
index 6c336432..a20d6873 100644
--- a/platforms/macos/src/node.rs
+++ b/platforms/macos/src/node.rs
@@ -15,11 +15,10 @@ use accesskit::{
 };
 use accesskit_consumer::{FilterResult, Node};
 use objc2::{
-    declare_class, msg_send_id,
-    mutability::InteriorMutable,
-    rc::Id,
+    define_class, msg_send,
+    rc::Retained,
     runtime::{AnyObject, Sel},
-    sel, ClassType, DeclaredClass,
+    sel, AllocAnyThread, DeclaredClass,
 };
 use objc2_app_kit::*;
 use objc2_foundation::{
@@ -347,26 +346,18 @@ pub(crate) struct PlatformNodeIvars {
     node_id: NodeId,
 }
 
-declare_class!(
+define_class!(
+    #[unsafe(super(NSAccessibilityElement))]
+    #[name = "AccessKitNode"]
+    #[ivars = PlatformNodeIvars]
     pub(crate) struct PlatformNode;
 
-    unsafe impl ClassType for PlatformNode {
-        #[inherits(NSObject)]
-        type Super = NSAccessibilityElement;
-        type Mutability = InteriorMutable;
-        const NAME: &'static str = "AccessKitNode";
-    }
-
-    impl DeclaredClass for PlatformNode {
-        type Ivars = PlatformNodeIvars;
-    }
-
-    unsafe impl PlatformNode {
-        #[method_id(accessibilityParent)]
-        fn parent(&self) -> Option<Id<AnyObject>> {
+    impl PlatformNode {
+        #[unsafe(method_id(accessibilityParent))]
+        fn parent(&self) -> Option<Retained<AnyObject>> {
             self.resolve_with_context(|node, context| {
                 if let Some(parent) = node.filtered_parent(&filter) {
-                    Some(Id::into_super(Id::into_super(Id::into_super(context.get_or_create_platform_node(parent.id())))))
+                    Some(context.get_or_create_platform_node(parent.id()).into_super().into_super().into_super())
                 } else {
                     context
                         .view
@@ -377,8 +368,8 @@ declare_class!(
             .flatten()
         }
 
-        #[method_id(accessibilityWindow)]
-        fn window(&self) -> Option<Id<AnyObject>> {
+        #[unsafe(method_id(accessibilityWindow))]
+        fn window(&self) -> Option<Retained<AnyObject>> {
             self.resolve_with_context(|_, context| {
                 context
                     .view
@@ -388,8 +379,8 @@ declare_class!(
             .flatten()
         }
 
-        #[method_id(accessibilityTopLevelUIElement)]
-        fn top_level(&self) -> Option<Id<AnyObject>> {
+        #[unsafe(method_id(accessibilityTopLevelUIElement))]
+        fn top_level(&self) -> Option<Retained<AnyObject>> {
             self.resolve_with_context(|_, context| {
                 context
                     .view
@@ -399,18 +390,18 @@ declare_class!(
             .flatten()
         }
 
-        #[method_id(accessibilityChildren)]
-        fn children(&self) -> Option<Id<NSArray<PlatformNode>>> {
+        #[unsafe(method_id(accessibilityChildren))]
+        fn children(&self) -> Option<Retained<NSArray<PlatformNode>>> {
             self.children_internal()
         }
 
-        #[method_id(accessibilityChildrenInNavigationOrder)]
-        fn children_in_navigation_order(&self) -> Option<Id<NSArray<PlatformNode>>> {
+        #[unsafe(method_id(accessibilityChildrenInNavigationOrder))]
+        fn children_in_navigation_order(&self) -> Option<Retained<NSArray<PlatformNode>>> {
             // For now, we assume the children are in navigation order.
             self.children_internal()
         }
 
-        #[method(accessibilityFrame)]
+        #[unsafe(method(accessibilityFrame))]
         fn frame(&self) -> NSRect {
             self.resolve_with_context(|node, context| {
                 let view = match context.view.load() {
@@ -434,42 +425,42 @@ declare_class!(
             .unwrap_or(NSRect::ZERO)
         }
 
-        #[method_id(accessibilityRole)]
-        fn role(&self) -> Id<NSAccessibilityRole> {
+        #[unsafe(method_id(accessibilityRole))]
+        fn role(&self) -> Retained<NSAccessibilityRole> {
             self.resolve(ns_role)
                 .unwrap_or(unsafe { NSAccessibilityUnknownRole })
                 .copy()
         }
 
-        #[method_id(accessibilitySubrole)]
-        fn sub_role(&self) -> Id<NSAccessibilitySubrole> {
+        #[unsafe(method_id(accessibilitySubrole))]
+        fn sub_role(&self) -> Retained<NSAccessibilitySubrole> {
             self.resolve(ns_sub_role)
                 .unwrap_or(unsafe { NSAccessibilityUnknownSubrole })
                 .copy()
         }
 
-        #[method_id(accessibilityRoleDescription)]
-        fn role_description(&self) -> Option<Id<NSString>> {
+        #[unsafe(method_id(accessibilityRoleDescription))]
+        fn role_description(&self) -> Option<Retained<NSString>> {
             self.resolve(|node| {
                 if let Some(role_description) = node.role_description() {
                     Some(NSString::from_str(role_description))
                 } else {
-                    unsafe { msg_send_id![super(self), accessibilityRoleDescription] }
+                    unsafe { msg_send![super(self), accessibilityRoleDescription] }
                 }
             })
             .flatten()
         }
 
-        #[method_id(accessibilityIdentifier)]
-        fn identifier(&self) -> Option<Id<NSString>> {
+        #[unsafe(method_id(accessibilityIdentifier))]
+        fn identifier(&self) -> Option<Retained<NSString>> {
             self.resolve(|node| {
                 node.author_id().map(NSString::from_str)
             })
             .flatten()
         }
 
-        #[method_id(accessibilityTitle)]
-        fn title(&self) -> Option<Id<NSString>> {
+        #[unsafe(method_id(accessibilityTitle))]
+        fn title(&self) -> Option<Retained<NSString>> {
             self.resolve(|node| {
                 let wrapper = NodeWrapper(node);
                 wrapper.title().map(|title| NSString::from_str(&title))
@@ -477,8 +468,8 @@ declare_class!(
             .flatten()
         }
 
-        #[method_id(accessibilityHelp)]
-        fn description(&self) -> Option<Id<NSString>> {
+        #[unsafe(method_id(accessibilityHelp))]
+        fn description(&self) -> Option<Retained<NSString>> {
             self.resolve(|node| {
                 let wrapper = NodeWrapper(node);
                 wrapper.description().map(|description| NSString::from_str(&description))
@@ -486,8 +477,8 @@ declare_class!(
             .flatten()
         }
 
-        #[method_id(accessibilityPlaceholderValue)]
-        fn placeholder(&self) -> Option<Id<NSString>> {
+        #[unsafe(method_id(accessibilityPlaceholderValue))]
+        fn placeholder(&self) -> Option<Retained<NSString>> {
             self.resolve(|node| {
                 let wrapper = NodeWrapper(node);
                 wrapper.placeholder().map(NSString::from_str)
@@ -495,48 +486,48 @@ declare_class!(
             .flatten()
         }
 
-        #[method_id(accessibilityValue)]
-        fn value(&self) -> Option<Id<NSObject>> {
+        #[unsafe(method_id(accessibilityValue))]
+        fn value(&self) -> Option<Retained<NSObject>> {
             self.resolve(|node| {
                 let wrapper = NodeWrapper(node);
                 wrapper.value().map(|value| match value {
                     Value::Bool(value) => {
-                        Id::into_super(Id::into_super(NSNumber::new_bool(value)))
+                        NSNumber::new_bool(value).into_super().into_super()
                     }
                     Value::Number(value) => {
-                        Id::into_super(Id::into_super(NSNumber::new_f64(value)))
+                        NSNumber::new_f64(value).into_super().into_super()
                     }
                     Value::String(value) => {
-                        Id::into_super(NSString::from_str(&value))
+                        NSString::from_str(&value).into_super()
                     }
                 })
             })
             .flatten()
         }
 
-        #[method(setAccessibilityValue:)]
+        #[unsafe(method(setAccessibilityValue:))]
         fn set_value(&self, _value: &NSObject) {
             // This isn't yet implemented. See the comment on this selector
             // in `is_selector_allowed`.
         }
 
-        #[method_id(accessibilityMinValue)]
-        fn min_value(&self) -> Option<Id<NSNumber>> {
+        #[unsafe(method_id(accessibilityMinValue))]
+        fn min_value(&self) -> Option<Retained<NSNumber>> {
             self.resolve(|node| {
                 node.min_numeric_value().map(NSNumber::new_f64)
             })
             .flatten()
         }
 
-        #[method_id(accessibilityMaxValue)]
-        fn max_value(&self) -> Option<Id<NSNumber>> {
+        #[unsafe(method_id(accessibilityMaxValue))]
+        fn max_value(&self) -> Option<Retained<NSNumber>> {
             self.resolve(|node| {
                 node.max_numeric_value().map(NSNumber::new_f64)
             })
             .flatten()
         }
 
-        #[method(accessibilityOrientation)]
+        #[unsafe(method(accessibilityOrientation))]
         fn orientation(&self) -> NSAccessibilityOrientation {
             self.resolve(|node| {
                 match node.orientation() {
@@ -548,24 +539,24 @@ declare_class!(
             .unwrap_or(NSAccessibilityOrientation::Unknown)
         }
 
-        #[method(isAccessibilityElement)]
+        #[unsafe(method(isAccessibilityElement))]
         fn is_accessibility_element(&self) -> bool {
             self.resolve(|node| filter(node) == FilterResult::Include)
                 .unwrap_or(false)
         }
 
-        #[method(isAccessibilityFocused)]
+        #[unsafe(method(isAccessibilityFocused))]
         fn is_focused(&self) -> bool {
             self.resolve(|node| node.is_focused() && can_be_focused(node))
                 .unwrap_or(false)
         }
 
-        #[method(isAccessibilityEnabled)]
+        #[unsafe(method(isAccessibilityEnabled))]
         fn is_enabled(&self) -> bool {
             self.resolve(|node| !node.is_disabled()).unwrap_or(false)
         }
 
-        #[method(setAccessibilityFocused:)]
+        #[unsafe(method(setAccessibilityFocused:))]
         fn set_focused(&self, focused: bool) {
             self.resolve_with_context(|node, context| {
                 if focused {
@@ -589,7 +580,7 @@ declare_class!(
             });
         }
 
-        #[method(accessibilityPerformPress)]
+        #[unsafe(method(accessibilityPerformPress))]
         fn press(&self) -> bool {
             self.resolve_with_context(|node, context| {
                 let clickable = node.is_clickable();
@@ -605,7 +596,7 @@ declare_class!(
             .unwrap_or(false)
         }
 
-        #[method(accessibilityPerformIncrement)]
+        #[unsafe(method(accessibilityPerformIncrement))]
         fn increment(&self) -> bool {
             self.resolve_with_context(|node, context| {
                 let supports_increment = node.supports_increment();
@@ -621,7 +612,7 @@ declare_class!(
             .unwrap_or(false)
         }
 
-        #[method(accessibilityPerformDecrement)]
+        #[unsafe(method(accessibilityPerformDecrement))]
         fn decrement(&self) -> bool {
             self.resolve_with_context(|node, context| {
                 let supports_decrement = node.supports_decrement();
@@ -637,12 +628,12 @@ declare_class!(
             .unwrap_or(false)
         }
 
-        #[method(accessibilityNotifiesWhenDestroyed)]
+        #[unsafe(method(accessibilityNotifiesWhenDestroyed))]
         fn notifies_when_destroyed(&self) -> bool {
             true
         }
 
-        #[method(accessibilityNumberOfCharacters)]
+        #[unsafe(method(accessibilityNumberOfCharacters))]
         fn number_of_characters(&self) -> NSInteger {
             self.resolve(|node| {
                 if node.supports_text_ranges() {
@@ -654,8 +645,8 @@ declare_class!(
             .unwrap_or(0)
         }
 
-        #[method_id(accessibilitySelectedText)]
-        fn selected_text(&self) -> Option<Id<NSString>> {
+        #[unsafe(method_id(accessibilitySelectedText))]
+        fn selected_text(&self) -> Option<Retained<NSString>> {
             self.resolve(|node| {
                 if node.supports_text_ranges() {
                     if let Some(range) = node.text_selection() {
@@ -668,7 +659,7 @@ declare_class!(
             .flatten()
         }
 
-        #[method(accessibilitySelectedTextRange)]
+        #[unsafe(method(accessibilitySelectedTextRange))]
         fn selected_text_range(&self) -> NSRange {
             self.resolve(|node| {
                 if node.supports_text_ranges() {
@@ -681,7 +672,7 @@ declare_class!(
             .unwrap_or_else(|| NSRange::new(0, 0))
         }
 
-        #[method(accessibilityInsertionPointLineNumber)]
+        #[unsafe(method(accessibilityInsertionPointLineNumber))]
         fn insertion_point_line_number(&self) -> NSInteger {
             self.resolve(|node| {
                 if node.supports_text_ranges() {
@@ -694,7 +685,7 @@ declare_class!(
             .unwrap_or(0)
         }
 
-        #[method(accessibilityRangeForLine:)]
+        #[unsafe(method(accessibilityRangeForLine:))]
         fn range_for_line(&self, line_index: NSInteger) -> NSRange {
             self.resolve(|node| {
                 if node.supports_text_ranges() && line_index >= 0 {
@@ -707,7 +698,7 @@ declare_class!(
             .unwrap_or_else(|| NSRange::new(0, 0))
         }
 
-        #[method(accessibilityRangeForPosition:)]
+        #[unsafe(method(accessibilityRangeForPosition:))]
         fn range_for_position(&self, point: NSPoint) -> NSRange {
             self.resolve_with_context(|node, context| {
                 let view = match context.view.load() {
@@ -727,8 +718,8 @@ declare_class!(
             .unwrap_or_else(|| NSRange::new(0, 0))
         }
 
-        #[method_id(accessibilityStringForRange:)]
-        fn string_for_range(&self, range: NSRange) -> Option<Id<NSString>> {
+        #[unsafe(method_id(accessibilityStringForRange:))]
+        fn string_for_range(&self, range: NSRange) -> Option<Retained<NSString>> {
             self.resolve(|node| {
                 if node.supports_text_ranges() {
                     if let Some(range) = from_ns_range(node, range) {
@@ -741,7 +732,7 @@ declare_class!(
             .flatten()
         }
 
-        #[method(accessibilityFrameForRange:)]
+        #[unsafe(method(accessibilityFrameForRange:))]
         fn frame_for_range(&self, range: NSRange) -> NSRect {
             self.resolve_with_context(|node, context| {
                 let view = match context.view.load() {
@@ -766,7 +757,7 @@ declare_class!(
             .unwrap_or(NSRect::ZERO)
         }
 
-        #[method(accessibilityLineForIndex:)]
+        #[unsafe(method(accessibilityLineForIndex:))]
         fn line_for_index(&self, index: NSInteger) -> NSInteger {
             self.resolve(|node| {
                 if node.supports_text_ranges() && index >= 0 {
@@ -779,7 +770,7 @@ declare_class!(
             .unwrap_or(0)
         }
 
-        #[method(accessibilityRangeForIndex:)]
+        #[unsafe(method(accessibilityRangeForIndex:))]
         fn range_for_index(&self, index: NSInteger) -> NSRange {
             self.resolve(|node| {
                 if node.supports_text_ranges() && index >= 0 {
@@ -792,7 +783,7 @@ declare_class!(
             .unwrap_or_else(|| NSRange::new(0, 0))
         }
 
-        #[method(setAccessibilitySelectedTextRange:)]
+        #[unsafe(method(setAccessibilitySelectedTextRange:))]
         fn set_selected_text_range(&self, range: NSRange) {
             self.resolve_with_context(|node, context| {
                 if node.supports_text_ranges() {
@@ -807,13 +798,13 @@ declare_class!(
             });
         }
 
-        #[method(isAccessibilityRequired)]
+        #[unsafe(method(isAccessibilityRequired))]
         fn is_required(&self) -> bool {
             self.resolve(|node| node.is_required())
                 .unwrap_or(false)
         }
 
-        #[method(isAccessibilitySelectorAllowed:)]
+        #[unsafe(method(isAccessibilitySelectorAllowed:))]
         fn is_selector_allowed(&self, selector: Sel) -> bool {
             self.resolve(|node| {
                 if selector == sel!(setAccessibilityFocused:) {
@@ -879,10 +870,10 @@ declare_class!(
 );
 
 impl PlatformNode {
-    pub(crate) fn new(context: Weak<Context>, node_id: NodeId) -> Id<Self> {
+    pub(crate) fn new(context: Weak<Context>, node_id: NodeId) -> Retained<Self> {
         let this = Self::alloc().set_ivars(PlatformNodeIvars { context, node_id });
 
-        unsafe { msg_send_id![super(this), init] }
+        unsafe { msg_send![super(this), init] }
     }
 
     fn resolve_with_context<F, T>(&self, f: F) -> Option<T>
@@ -903,13 +894,13 @@ impl PlatformNode {
         self.resolve_with_context(|node, _| f(node))
     }
 
-    fn children_internal(&self) -> Option<Id<NSArray<PlatformNode>>> {
+    fn children_internal(&self) -> Option<Retained<NSArray<PlatformNode>>> {
         self.resolve_with_context(|node, context| {
             let platform_nodes = node
                 .filtered_children(filter)
                 .map(|child| context.get_or_create_platform_node(child.id()))
-                .collect::<Vec<Id<PlatformNode>>>();
-            NSArray::from_vec(platform_nodes)
+                .collect::<Vec<Retained<PlatformNode>>>();
+            NSArray::from_retained_slice(&platform_nodes)
         })
     }
 }
diff --git a/platforms/macos/src/patch.rs b/platforms/macos/src/patch.rs
index 2dab00f2..e1f99d2c 100644
--- a/platforms/macos/src/patch.rs
+++ b/platforms/macos/src/patch.rs
@@ -7,7 +7,7 @@ use objc2::{
     encode::{Encode, EncodeArguments, EncodeReturn, Encoding},
     ffi::class_addMethod,
     msg_send,
-    runtime::{AnyClass, AnyObject, Bool, MethodImplementation, Sel},
+    runtime::{AnyClass, AnyObject, MethodImplementation, Sel},
     sel, Message,
 };
 use objc2_app_kit::NSWindow;
@@ -36,7 +36,8 @@ extern "C" fn focus_forwarder(this: &NSWindow, _cmd: Sel) -> *mut AnyObject {
 /// Also, this function assumes that the specified class is a subclass
 /// of `NSWindow`.
 pub unsafe fn add_focus_forwarder_to_window_class(class_name: &str) {
-    let class = AnyClass::get(class_name).unwrap();
+    let class_name = CString::new(class_name).unwrap();
+    let class = AnyClass::get(&class_name).unwrap();
     unsafe {
         add_method(
             class as *const AnyClass as *mut AnyClass,
@@ -66,19 +67,12 @@ where
     );
 
     let types = method_type_encoding(&F::Return::ENCODING_RETURN, encs);
-    let success = Bool::from_raw(unsafe {
-        class_addMethod(
-            class as *mut _,
-            sel.as_ptr(),
-            Some(func.__imp()),
-            types.as_ptr(),
-        )
-    });
+    let success = unsafe { class_addMethod(class as *mut _, sel, func.__imp(), types.as_ptr()) };
     assert!(success.as_bool(), "Failed to add method {:?}", sel);
 }
 
 fn count_args(sel: Sel) -> usize {
-    sel.name().chars().filter(|&c| c == ':').count()
+    sel.name().to_bytes().iter().filter(|&&b| b == b':').count()
 }
 
 fn method_type_encoding(ret: &Encoding, args: &[Encoding]) -> CString {
diff --git a/platforms/macos/src/subclass.rs b/platforms/macos/src/subclass.rs
index 0b9a2d53..2e5d608b 100644
--- a/platforms/macos/src/subclass.rs
+++ b/platforms/macos/src/subclass.rs
@@ -6,20 +6,23 @@
 use accesskit::{ActionHandler, ActivationHandler, TreeUpdate};
 use objc2::{
     declare::ClassBuilder,
-    declare_class,
+    define_class,
     ffi::{
         objc_getAssociatedObject, objc_setAssociatedObject, object_setClass,
         OBJC_ASSOCIATION_RETAIN_NONATOMIC,
     },
-    msg_send_id,
-    mutability::InteriorMutable,
-    rc::Id,
+    msg_send,
+    rc::Retained,
     runtime::{AnyClass, Sel},
-    sel, ClassType, DeclaredClass,
+    sel, AllocAnyThread, DeclaredClass,
 };
 use objc2_app_kit::{NSView, NSWindow};
 use objc2_foundation::{NSArray, NSObject, NSPoint};
-use std::{cell::RefCell, ffi::c_void, sync::Mutex};
+use std::{
+    cell::RefCell,
+    ffi::{c_void, CStr},
+    sync::Mutex,
+};
 
 use crate::{event::QueuedEvents, Adapter};
 
@@ -41,18 +44,11 @@ struct AssociatedObjectIvars {
     prev_class: &'static AnyClass,
 }
 
-declare_class!(
+define_class!(
+    #[unsafe(super(NSObject))]
+    #[name = "AccessKitSubclassAssociatedObject"]
+    #[ivars = AssociatedObjectIvars]
     struct AssociatedObject;
-
-    unsafe impl ClassType for AssociatedObject {
-        type Super = NSObject;
-        type Mutability = InteriorMutable;
-        const NAME: &'static str = "AccessKitSubclassAssociatedObject";
-    }
-
-    impl DeclaredClass for AssociatedObject {
-        type Ivars = AssociatedObjectIvars;
-    }
 );
 
 impl AssociatedObject {
@@ -60,14 +56,14 @@ impl AssociatedObject {
         adapter: Adapter,
         activation_handler: impl 'static + ActivationHandler,
         prev_class: &'static AnyClass,
-    ) -> Id<Self> {
+    ) -> Retained<Self> {
         let state = RefCell::new(AssociatedObjectState {
             adapter,
             activation_handler: Box::new(activation_handler),
         });
         let this = Self::alloc().set_ivars(AssociatedObjectIvars { state, prev_class });
 
-        unsafe { msg_send_id![super(this), init] }
+        unsafe { msg_send![super(this), init] }
     }
 }
 
@@ -116,8 +112,8 @@ unsafe extern "C" fn hit_test(this: &NSView, _cmd: Sel, point: NSPoint) -> *mut
 /// Uses dynamic Objective-C subclassing to implement the `NSView`
 /// accessibility methods when normal subclassing isn't an option.
 pub struct SubclassingAdapter {
-    view: Id<NSView>,
-    associated: Id<AssociatedObject>,
+    view: Retained<NSView>,
+    associated: Retained<AssociatedObject>,
 }
 
 impl SubclassingAdapter {
@@ -136,16 +132,16 @@ impl SubclassingAdapter {
         action_handler: impl 'static + ActionHandler,
     ) -> Self {
         let view = view as *mut NSView;
-        let retained_view = unsafe { Id::retain(view) }.unwrap();
+        let retained_view = unsafe { Retained::retain(view) }.unwrap();
         Self::new_internal(retained_view, activation_handler, action_handler)
     }
 
     fn new_internal(
-        retained_view: Id<NSView>,
+        retained_view: Retained<NSView>,
         activation_handler: impl 'static + ActivationHandler,
         action_handler: impl 'static + ActionHandler,
     ) -> Self {
-        let view = Id::as_ptr(&retained_view) as *mut NSView;
+        let view = Retained::as_ptr(&retained_view) as *mut NSView;
         let adapter = unsafe { Adapter::new(view as *mut c_void, false, action_handler) };
         // Cast to a pointer and back to force the lifetime to 'static
         // SAFETY: We know the class will live as long as the instance,
@@ -156,7 +152,7 @@ impl SubclassingAdapter {
             objc_setAssociatedObject(
                 view as *mut _,
                 associated_object_key(),
-                Id::as_ptr(&associated) as *mut _,
+                Retained::as_ptr(&associated) as *mut _,
                 OBJC_ASSOCIATION_RETAIN_NONATOMIC,
             )
         };
@@ -164,8 +160,10 @@ impl SubclassingAdapter {
         let subclass = match subclasses.iter().find(|entry| entry.0 == prev_class) {
             Some(entry) => entry.1,
             None => {
-                let name = format!("AccessKitSubclassOf{}", prev_class.name());
-                let mut builder = ClassBuilder::new(&name, prev_class).unwrap();
+                let mut name_bytes = Vec::from("AccessKitSubclassOf".as_bytes());
+                name_bytes.extend_from_slice(prev_class.name().to_bytes_with_nul());
+                let name = CStr::from_bytes_with_nul(&name_bytes).unwrap();
+                let mut builder = ClassBuilder::new(name, prev_class).unwrap();
                 unsafe {
                     builder.add_method(
                         sel!(superclass),
@@ -251,7 +249,7 @@ impl SubclassingAdapter {
 impl Drop for SubclassingAdapter {
     fn drop(&mut self) {
         let prev_class = self.associated.ivars().prev_class;
-        let view = Id::as_ptr(&self.view) as *mut NSView;
+        let view = Retained::as_ptr(&self.view) as *mut NSView;
         unsafe { object_setClass(view as *mut _, (prev_class as *const AnyClass).cast()) };
         unsafe {
             objc_setAssociatedObject(