diff --git a/Examples/SyncUps/SyncUps/AppFeature.swift b/Examples/SyncUps/SyncUps/AppFeature.swift
index 5b57e9de647a..17d9360ef14a 100644
--- a/Examples/SyncUps/SyncUps/AppFeature.swift
+++ b/Examples/SyncUps/SyncUps/AppFeature.swift
@@ -71,18 +71,13 @@ struct AppView: View {
 }
 
 #Preview {
-  AppView(
-    store: Store(
-      initialState: AppFeature.State(
-        syncUpsList: SyncUpsList.State(
-          syncUps: [
-            .mock,
-            .productMock,
-            .engineeringMock,
-          ]
-        )
-      )
-    ) {
+  @Shared(.syncUps) var syncUps: IdentifiedArrayOf<SyncUp> = [
+    .mock,
+    .productMock,
+    .engineeringMock
+  ]
+  return AppView(
+    store: Store(initialState: AppFeature.State()) {
       AppFeature()
     }
   )
diff --git a/Examples/SyncUps/SyncUps/Meeting.swift b/Examples/SyncUps/SyncUps/Meeting.swift
index c278bfcfbbc2..d6ac16babb62 100644
--- a/Examples/SyncUps/SyncUps/Meeting.swift
+++ b/Examples/SyncUps/SyncUps/Meeting.swift
@@ -7,19 +7,19 @@ struct MeetingView: View {
   var body: some View {
     Form {
       Section {
-        ForEach(self.syncUp.attendees) { attendee in
+        ForEach(syncUp.attendees) { attendee in
           Text(attendee.name)
         }
       } header: {
         Text("Attendees")
       }
       Section {
-        Text(self.meeting.transcript)
+        Text(meeting.transcript)
       } header: {
         Text("Transcript")
       }
     }
-    .navigationTitle(Text(self.meeting.date, style: .date))
+    .navigationTitle(Text(meeting.date, style: .date))
   }
 }
 
diff --git a/Examples/SyncUps/SyncUps/Models.swift b/Examples/SyncUps/SyncUps/Models.swift
index a88a7465a87e..dc8bfa60ab13 100644
--- a/Examples/SyncUps/SyncUps/Models.swift
+++ b/Examples/SyncUps/SyncUps/Models.swift
@@ -11,7 +11,7 @@ struct SyncUp: Equatable, Identifiable, Codable {
   var title = ""
 
   var durationPerAttendee: Duration {
-    self.duration / self.attendees.count
+    duration / attendees.count
   }
 }
 
@@ -56,9 +56,9 @@ enum Theme: String, CaseIterable, Equatable, Identifiable, Codable {
     }
   }
 
-  var mainColor: Color { Color(self.rawValue) }
+  var mainColor: Color { Color(rawValue) }
 
-  var name: String { self.rawValue.capitalized }
+  var name: String { rawValue.capitalized }
 }
 
 extension SyncUp {
diff --git a/Examples/SyncUps/SyncUps/RecordMeeting.swift b/Examples/SyncUps/SyncUps/RecordMeeting.swift
index 312afc16dd0f..c2765744ef4d 100644
--- a/Examples/SyncUps/SyncUps/RecordMeeting.swift
+++ b/Examples/SyncUps/SyncUps/RecordMeeting.swift
@@ -13,7 +13,7 @@ struct RecordMeeting {
     var transcript = ""
 
     var durationRemaining: Duration {
-      self.syncUp.duration - .seconds(self.secondsElapsed)
+      syncUp.duration - .seconds(secondsElapsed)
     }
   }
 
@@ -41,11 +41,11 @@ struct RecordMeeting {
     Reduce { state, action in
       switch action {
       case .alert(.presented(.confirmDiscard)):
-        return .run { _ in await self.dismiss() }
+        return .run { _ in await dismiss() }
 
       case .alert(.presented(.confirmSave)):
         state.syncUp.insert(transcript: state.transcript)
-        return .run { _ in await self.dismiss() }
+        return .run { _ in await dismiss() }
 
       case .alert:
         return .none
@@ -68,18 +68,18 @@ struct RecordMeeting {
       case .onTask:
         return .run { send in
           let authorization =
-            await self.speechClient.authorizationStatus() == .notDetermined
-            ? self.speechClient.requestAuthorization()
-            : self.speechClient.authorizationStatus()
+            await speechClient.authorizationStatus() == .notDetermined
+            ? speechClient.requestAuthorization()
+            : speechClient.authorizationStatus()
 
           await withTaskGroup(of: Void.self) { group in
             if authorization == .authorized {
               group.addTask {
-                await self.startSpeechRecognition(send: send)
+                await startSpeechRecognition(send: send)
               }
             }
             group.addTask {
-              await self.startTimer(send: send)
+              await startTimer(send: send)
             }
           }
         }
@@ -94,7 +94,7 @@ struct RecordMeeting {
         if state.secondsElapsed.isMultiple(of: secondsPerAttendee) {
           if state.secondsElapsed == state.syncUp.duration.components.seconds {
             state.syncUp.insert(transcript: state.transcript)
-            return .run { _ in await self.dismiss() }
+            return .run { _ in await dismiss() }
           }
           state.speakerIndex += 1
         }
@@ -118,7 +118,7 @@ struct RecordMeeting {
 
   private func startSpeechRecognition(send: Send<Action>) async {
     do {
-      let speechTask = await self.speechClient.startTask(SFSpeechAudioBufferRecognitionRequest())
+      let speechTask = await speechClient.startTask(SFSpeechAudioBufferRecognitionRequest())
       for try await result in speechTask {
         await send(.speechResult(result))
       }
@@ -128,7 +128,7 @@ struct RecordMeeting {
   }
 
   private func startTimer(send: Send<Action>) async {
-    for await _ in self.clock.timer(interval: .seconds(1)) {
+    for await _ in clock.timer(interval: .seconds(1)) {
       await send(.timerTick)
     }
   }
@@ -138,7 +138,7 @@ extension SyncUp {
   fileprivate mutating func insert(transcript: String) {
     @Dependency(\.date.now) var now
     @Dependency(\.uuid) var uuid
-    self.meetings.insert(
+    meetings.insert(
       Meeting(
         id: Meeting.ID(uuid()),
         date: now,
@@ -239,14 +239,14 @@ struct MeetingHeaderView: View {
 
   var body: some View {
     VStack {
-      ProgressView(value: self.progress)
-        .progressViewStyle(MeetingProgressViewStyle(theme: self.theme))
+      ProgressView(value: progress)
+        .progressViewStyle(MeetingProgressViewStyle(theme: theme))
       HStack {
         VStack(alignment: .leading) {
           Text("Time Elapsed")
             .font(.caption)
           Label(
-            Duration.seconds(self.secondsElapsed).formatted(.units()),
+            Duration.seconds(secondsElapsed).formatted(.units()),
             systemImage: "hourglass.bottomhalf.fill"
           )
         }
@@ -254,7 +254,7 @@ struct MeetingHeaderView: View {
         VStack(alignment: .trailing) {
           Text("Time Remaining")
             .font(.caption)
-          Label(self.durationRemaining.formatted(.units()), systemImage: "hourglass.tophalf.fill")
+          Label(durationRemaining.formatted(.units()), systemImage: "hourglass.tophalf.fill")
             .font(.body.monospacedDigit())
             .labelStyle(.trailingIcon)
         }
@@ -264,12 +264,12 @@ struct MeetingHeaderView: View {
   }
 
   private var totalDuration: Duration {
-    .seconds(self.secondsElapsed) + self.durationRemaining
+    .seconds(secondsElapsed) + durationRemaining
   }
 
   private var progress: Double {
-    guard self.totalDuration > .seconds(0) else { return 0 }
-    return Double(self.secondsElapsed) / Double(self.totalDuration.components.seconds)
+    guard totalDuration > .seconds(0) else { return 0 }
+    return Double(secondsElapsed) / Double(totalDuration.components.seconds)
   }
 }
 
@@ -279,11 +279,11 @@ struct MeetingProgressViewStyle: ProgressViewStyle {
   func makeBody(configuration: Configuration) -> some View {
     ZStack {
       RoundedRectangle(cornerRadius: 10)
-        .fill(self.theme.accentColor)
+        .fill(theme.accentColor)
         .frame(height: 20)
 
       ProgressView(configuration)
-        .tint(self.theme.mainColor)
+        .tint(theme.mainColor)
         .frame(height: 12)
         .padding(.horizontal)
     }
@@ -300,8 +300,8 @@ struct MeetingTimerView: View {
       .overlay {
         VStack {
           Group {
-            if self.speakerIndex < self.syncUp.attendees.count {
-              Text(self.syncUp.attendees[self.speakerIndex].name)
+            if speakerIndex < syncUp.attendees.count {
+              Text(syncUp.attendees[speakerIndex].name)
             } else {
               Text("Someone")
             }
@@ -312,14 +312,14 @@ struct MeetingTimerView: View {
             .font(.largeTitle)
             .padding(.top)
         }
-        .foregroundStyle(self.syncUp.theme.accentColor)
+        .foregroundStyle(syncUp.theme.accentColor)
       }
       .overlay {
-        ForEach(Array(self.syncUp.attendees.enumerated()), id: \.element.id) { index, attendee in
-          if index < self.speakerIndex + 1 {
-            SpeakerArc(totalSpeakers: self.syncUp.attendees.count, speakerIndex: index)
+        ForEach(Array(syncUp.attendees.enumerated()), id: \.element.id) { index, attendee in
+          if index < speakerIndex + 1 {
+            SpeakerArc(totalSpeakers: syncUp.attendees.count, speakerIndex: index)
               .rotation(Angle(degrees: -90))
-              .stroke(self.syncUp.theme.mainColor, lineWidth: 12)
+              .stroke(syncUp.theme.mainColor, lineWidth: 12)
           }
         }
       }
@@ -339,21 +339,21 @@ struct SpeakerArc: Shape {
       path.addArc(
         center: center,
         radius: radius,
-        startAngle: self.startAngle,
-        endAngle: self.endAngle,
+        startAngle: startAngle,
+        endAngle: endAngle,
         clockwise: false
       )
     }
   }
 
   private var degreesPerSpeaker: Double {
-    360 / Double(self.totalSpeakers)
+    360 / Double(totalSpeakers)
   }
   private var startAngle: Angle {
-    Angle(degrees: self.degreesPerSpeaker * Double(self.speakerIndex) + 1)
+    Angle(degrees: degreesPerSpeaker * Double(speakerIndex) + 1)
   }
   private var endAngle: Angle {
-    Angle(degrees: self.startAngle.degrees + self.degreesPerSpeaker - 1)
+    Angle(degrees: startAngle.degrees + degreesPerSpeaker - 1)
   }
 }
 
@@ -365,13 +365,13 @@ struct MeetingFooterView: View {
   var body: some View {
     VStack {
       HStack {
-        if self.speakerIndex < self.syncUp.attendees.count - 1 {
-          Text("Speaker \(self.speakerIndex + 1) of \(self.syncUp.attendees.count)")
+        if speakerIndex < syncUp.attendees.count - 1 {
+          Text("Speaker \(speakerIndex + 1) of \(syncUp.attendees.count)")
         } else {
           Text("No more speakers.")
         }
         Spacer()
-        Button(action: self.nextButtonTapped) {
+        Button(action: nextButtonTapped) {
           Image(systemName: "forward.fill")
         }
       }
diff --git a/Examples/SyncUps/SyncUps/SyncUpDetail.swift b/Examples/SyncUps/SyncUps/SyncUpDetail.swift
index 35de892a7ce5..48397c31be5f 100644
--- a/Examples/SyncUps/SyncUps/SyncUpDetail.swift
+++ b/Examples/SyncUps/SyncUps/SyncUpDetail.swift
@@ -65,13 +65,13 @@ struct SyncUpDetail {
         case .confirmDeletion:
           @Shared(.syncUps) var syncUps: IdentifiedArrayOf<SyncUp> = []
           syncUps.remove(id: state.syncUp.id)
-          return .run { _ in await self.dismiss() }
+          return .run { _ in await dismiss() }
 
         case .continueWithoutRecording:
           return .send(.delegate(.startMeeting))
 
         case .openSettings:
-          return .run { _ in await self.openSettings() }
+          return .run { _ in await openSettings() }
         }
 
       case .destination:
@@ -89,7 +89,7 @@ struct SyncUpDetail {
         return .none
 
       case .startMeetingButtonTapped:
-        switch self.authorizationStatus() {
+        switch authorizationStatus() {
         case .notDetermined, .authorized:
           return .send(.delegate(.startMeeting))
 
diff --git a/Examples/SyncUps/SyncUps/SyncUpForm.swift b/Examples/SyncUps/SyncUps/SyncUpForm.swift
index 8a09b0a10e68..4e5e25e8d2ab 100644
--- a/Examples/SyncUps/SyncUps/SyncUpForm.swift
+++ b/Examples/SyncUps/SyncUps/SyncUpForm.swift
@@ -37,7 +37,7 @@ struct SyncUpForm {
     Reduce { state, action in
       switch action {
       case .addAttendeeButtonTapped:
-        let attendee = Attendee(id: Attendee.ID(self.uuid()))
+        let attendee = Attendee(id: Attendee.ID(uuid()))
         state.syncUp.attendees.append(attendee)
         state.focus = .attendee(attendee.id)
         return .none
@@ -48,7 +48,7 @@ struct SyncUpForm {
       case let .deleteAttendees(atOffsets: indices):
         state.syncUp.attendees.remove(atOffsets: indices)
         if state.syncUp.attendees.isEmpty {
-          state.syncUp.attendees.append(Attendee(id: Attendee.ID(self.uuid())))
+          state.syncUp.attendees.append(Attendee(id: Attendee.ID(uuid())))
         }
         guard let firstIndex = indices.first
         else { return .none }
@@ -104,7 +104,7 @@ struct ThemePicker: View {
   @Binding var selection: Theme
 
   var body: some View {
-    Picker("Theme", selection: self.$selection) {
+    Picker("Theme", selection: $selection) {
       ForEach(Theme.allCases) { theme in
         ZStack {
           RoundedRectangle(cornerRadius: 4)
@@ -122,7 +122,7 @@ struct ThemePicker: View {
 
 extension Duration {
   fileprivate var minutes: Double {
-    get { Double(self.components.seconds / 60) }
+    get { Double(components.seconds / 60) }
     set { self = .seconds(newValue * 60) }
   }
 }
diff --git a/Examples/SyncUps/SyncUps/SyncUpsList.swift b/Examples/SyncUps/SyncUps/SyncUpsList.swift
index ae72ec826be9..2bf5895d4253 100644
--- a/Examples/SyncUps/SyncUps/SyncUpsList.swift
+++ b/Examples/SyncUps/SyncUps/SyncUpsList.swift
@@ -36,7 +36,7 @@ struct SyncUpsList {
       case .addSyncUpButtonTapped:
         state.destination = .add(
           SyncUpForm.State(
-            syncUp: SyncUp(id: SyncUp.ID(self.uuid()))
+            syncUp: SyncUp(id: SyncUp.ID(uuid()))
           )
         )
         return .none
@@ -51,7 +51,7 @@ struct SyncUpsList {
         if syncUp.attendees.isEmpty {
           syncUp.attendees.append(
             editState.syncUp.attendees.first
-              ?? Attendee(id: Attendee.ID(self.uuid()))
+              ?? Attendee(id: Attendee.ID(uuid()))
           )
         }
         state.syncUps.append(syncUp)
@@ -123,19 +123,19 @@ struct CardView: View {
 
   var body: some View {
     VStack(alignment: .leading) {
-      Text(self.syncUp.title)
+      Text(syncUp.title)
         .font(.headline)
       Spacer()
       HStack {
-        Label("\(self.syncUp.attendees.count)", systemImage: "person.3")
+        Label("\(syncUp.attendees.count)", systemImage: "person.3")
         Spacer()
-        Label(self.syncUp.duration.formatted(.units()), systemImage: "clock")
+        Label(syncUp.duration.formatted(.units()), systemImage: "clock")
           .labelStyle(.trailingIcon)
       }
       .font(.caption)
     }
     .padding()
-    .foregroundColor(self.syncUp.theme.accentColor)
+    .foregroundColor(syncUp.theme.accentColor)
   }
 }
 
@@ -152,23 +152,18 @@ extension LabelStyle where Self == TrailingIconLabelStyle {
   static var trailingIcon: Self { Self() }
 }
 
-struct SyncUpsList_Previews: PreviewProvider {
-  static var previews: some View {
-    NavigationStack {
-      SyncUpsListView(
-        store: Store(
-          initialState: SyncUpsList.State(
-            syncUps: [
-              .mock,
-              .productMock,
-              .engineeringMock,
-            ]
-          )
-        ) {
-          SyncUpsList()
-        }
-      )
-    }
+#Preview("List") {
+  @Shared(.syncUps) var syncUps: IdentifiedArrayOf<SyncUp> = [
+    .mock,
+    .productMock,
+    .engineeringMock
+  ]
+  return NavigationStack {
+    SyncUpsListView(
+      store: Store(initialState: SyncUpsList.State()) {
+        SyncUpsList()
+      }
+    )
   }
 }
 
diff --git a/Sources/ComposableArchitecture/Reducer/Reducers/DebugReducer.swift b/Sources/ComposableArchitecture/Reducer/Reducers/DebugReducer.swift
index a8b4de4ae229..53574d3492dc 100644
--- a/Sources/ComposableArchitecture/Reducer/Reducers/DebugReducer.swift
+++ b/Sources/ComposableArchitecture/Reducer/Reducers/DebugReducer.swift
@@ -80,24 +80,20 @@ public struct _PrintChangesReducer<Base: Reducer>: Reducer {
   ) -> Effect<Base.Action> {
     #if DEBUG
       if let printer = self.printer {
-        return withSharedChangeTracking {
+        return withSharedChangeTracking { changeTracker in
           let oldState = state
           let effects = self.base.reduce(into: &state, action: action)
-          @Dependency(SharedChangeTrackerKey.self) var changeTracker
-          guard let changeTracker
-          else { return effects }
           return withEscapedDependencies { continuation in
             effects.merge(
               with: .publisher { [newState = state, queue = printer.queue] in
                 Deferred<Empty<Action, Never>> {
                   queue.async {
                     continuation.yield {
-                      let wasAsserting = changeTracker.isAsserting
-                      changeTracker.isAsserting = true
-                      defer { changeTracker.isAsserting = wasAsserting }
-                      printer.printChange(
-                        receivedAction: action, oldState: oldState, newState: newState
-                      )
+                      changeTracker.assert {
+                        printer.printChange(
+                          receivedAction: action, oldState: oldState, newState: newState
+                        )
+                      }
                     }
                   }
                   return Empty()
diff --git a/Sources/ComposableArchitecture/SharedState/Shared.swift b/Sources/ComposableArchitecture/SharedState/Shared.swift
index a1ebaf6ef8da..b4248830543c 100644
--- a/Sources/ComposableArchitecture/SharedState/Shared.swift
+++ b/Sources/ComposableArchitecture/SharedState/Shared.swift
@@ -19,7 +19,7 @@ public struct Shared<Value> {
   public var wrappedValue: Value {
     get {
       @Dependency(SharedChangeTrackerKey.self) var changeTracker
-      if changeTracker?.isAsserting == true {
+      if changeTracker != nil {
         return self.snapshot ?? self.currentValue
       } else {
         return self.currentValue
@@ -27,10 +27,17 @@ public struct Shared<Value> {
     }
     nonmutating set {
       @Dependency(SharedChangeTrackerKey.self) var changeTracker
-      if changeTracker?.isAsserting == true {
+      if changeTracker != nil {
         self.snapshot = newValue
       } else {
-        changeTracker?.track(self.reference)
+        @Dependency(SharedChangeTrackersKey.self)
+        var changeTrackers: LockIsolated<Set<SharedChangeTracker>>
+
+        changeTrackers.withValue { changeTrackers in
+          for changeTracker in changeTrackers {
+            changeTracker.track(self.reference)
+          }
+        }
         self.currentValue = newValue
       }
     }
@@ -119,28 +126,25 @@ public struct Shared<Value> {
     file: StaticString = #file,
     line: UInt = #line
   ) rethrows where Value: Equatable {
-    @Dependency(SharedChangeTrackerKey.self) var changeTracker
-    guard let changeTracker
+    @Dependency(SharedChangeTrackersKey.self) var changeTrackers
+    guard
+      let changeTracker = changeTrackers.value
+        .first(where: { $0.changes[ObjectIdentifier(self.reference)] != nil })
     else {
-      XCTFail(
-        "Use 'withSharedChangeTracking' to track changes to assert against.",
-        file: file,
-        line: line
-      )
-      return
-    }
-    let wasAsserting = changeTracker.isAsserting
-    changeTracker.isAsserting = true
-    defer { changeTracker.isAsserting = wasAsserting }
-    guard var snapshot = self.snapshot, snapshot != self.currentValue else {
       XCTFail("Expected changes, but none occurred.", file: file, line: line)
       return
     }
-    try updateValueToExpectedResult(&snapshot)
-    self.snapshot = snapshot
-    // TODO: Finesse error more than `XCTAssertNoDifference`
-    XCTAssertNoDifference(self.currentValue, self.snapshot, file: file, line: line)
-    self.snapshot = nil
+    try changeTracker.assert {
+      guard var snapshot = self.snapshot, snapshot != self.currentValue else {
+        XCTFail("Expected changes, but none occurred.", file: file, line: line)
+        return
+      }
+      try updateValueToExpectedResult(&snapshot)
+      self.snapshot = snapshot
+      // TODO: Finesse error more than `XCTAssertNoDifference`
+      XCTAssertNoDifference(self.currentValue, self.snapshot, file: file, line: line)
+      self.snapshot = nil
+    }
   }
 
   private var currentValue: Value {
@@ -196,7 +200,7 @@ extension Shared: @unchecked Sendable where Value: Sendable {}
 extension Shared: Equatable where Value: Equatable {
   public static func == (lhs: Shared, rhs: Shared) -> Bool {
     @Dependency(SharedChangeTrackerKey.self) var changeTracker
-    if changeTracker?.isAsserting == true, lhs.reference === rhs.reference {
+    if changeTracker != nil, lhs.reference === rhs.reference {
       if let lhsReference = lhs.reference as? any Equatable {
         func open<T: Equatable>(_ lhsReference: T) -> Bool {
           lhsReference == rhs.reference as? T
diff --git a/Sources/ComposableArchitecture/SharedState/SharedChangeTracking.swift b/Sources/ComposableArchitecture/SharedState/SharedChangeTracking.swift
index e64a494a0b51..88122e0341d1 100644
--- a/Sources/ComposableArchitecture/SharedState/SharedChangeTracking.swift
+++ b/Sources/ComposableArchitecture/SharedState/SharedChangeTracking.swift
@@ -1,25 +1,21 @@
 import CustomDump
 import Dependencies
 
-public func withSharedChangeTracking<T>(
-  _ apply: () throws -> T
+func withSharedChangeTracking<T>(
+  _ apply: (SharedChangeTracker) throws -> T
 ) rethrows -> T {
-  try withDependencies {
-    $0[SharedChangeTrackerKey.self] = $0[SharedChangeTrackerKey.self]?.copy()
-      ?? SharedChangeTracker()
-  } operation: {
-    try apply()
+  let changeTracker = SharedChangeTracker()
+  return try changeTracker.track {
+    try apply(changeTracker)
   }
 }
 
-public func withSharedChangeTracking<T>(
-  _ apply: () async throws -> T
+func withSharedChangeTracking<T>(
+  _ apply: (SharedChangeTracker) async throws -> T
 ) async rethrows -> T {
-  try await withDependencies {
-    $0[SharedChangeTrackerKey.self] = $0[SharedChangeTrackerKey.self]?.copy()
-      ?? SharedChangeTracker()
-  } operation: {
-    try await apply()
+  let changeTracker = SharedChangeTracker()
+  return try await changeTracker.track {
+    try await apply(changeTracker)
   }
 }
 
@@ -58,23 +54,22 @@ struct AnyChange<Value>: Change {
   }
 }
 
-@_spi(Internals) public final class SharedChangeTracker {
-  var changes: [ObjectIdentifier: Any] = [:]
-  @_spi(Internals) public var isAsserting = false
-  @_spi(Internals) public var hasChanges: Bool { !self.changes.isEmpty }
-  @_spi(Internals) public init() {}
-  @_spi(Internals) public func resetChanges() { self.changes.removeAll() }
-  @_spi(Internals) public func assertUnchanged() {
+final class SharedChangeTracker: Sendable {
+  let changes: LockIsolated<[ObjectIdentifier: Any]> = LockIsolated([:])
+  var hasChanges: Bool { !self.changes.isEmpty }
+  init() {}
+  func resetChanges() { self.changes.withValue { $0.removeAll() } }
+  func assertUnchanged() {
     for change in self.changes.values {
       if let change = change as? any Change {
         change.assertUnchanged()
       }
     }
-    self.changes.removeAll()
+    self.resetChanges()
   }
   func track<Value>(_ reference: some Reference<Value>) {
     if !self.changes.keys.contains(ObjectIdentifier(reference)) {
-      self.changes[ObjectIdentifier(reference)] = AnyChange(reference)
+      self.changes.withValue { $0[ObjectIdentifier(reference)] = AnyChange(reference) }
     }
   }
   subscript<Value>(_ reference: some Reference<Value>) -> AnyChange<Value>? {
@@ -82,17 +77,49 @@ struct AnyChange<Value>: Change {
     _modify {
       var change = self.changes[ObjectIdentifier(reference)] as? AnyChange<Value>
       yield &change
-      self.changes[ObjectIdentifier(reference)] = change
+      self.changes.withValue { [change] in $0[ObjectIdentifier(reference)] = change }
+    }
+  }
+  func track<R>(_ operation: () throws -> R) rethrows -> R {
+    @Dependency(SharedChangeTrackersKey.self)
+    var sharedChangeTrackers: LockIsolated<Set<SharedChangeTracker>>
+    sharedChangeTrackers.withValue { _ = $0.insert(self) }
+    defer { sharedChangeTrackers.withValue { _ = $0.remove(self) } }
+    return try operation()
+  }
+  func track<R>(_ operation: () async throws -> R) async rethrows -> R {
+    @Dependency(SharedChangeTrackersKey.self)
+    var sharedChangeTrackers: LockIsolated<Set<SharedChangeTracker>>
+    sharedChangeTrackers.withValue { _ = $0.insert(self) }
+    defer { sharedChangeTrackers.withValue { _ = $0.remove(self) } }
+    return try await operation()
+  }
+  func assert<R>(_ operation: () throws -> R) rethrows -> R {
+    try withDependencies {
+      $0[SharedChangeTrackerKey.self] = self
+    } operation: {
+      try operation()
     }
   }
-  func copy() -> SharedChangeTracker {
-    let changeTracker = SharedChangeTracker()
-    changeTracker.changes = self.changes
-    return changeTracker
+}
+
+extension SharedChangeTracker: Hashable {
+  static func == (lhs: SharedChangeTracker, rhs: SharedChangeTracker) -> Bool {
+    lhs === rhs
+  }
+  func hash(into hasher: inout Hasher) {
+    hasher.combine(ObjectIdentifier(self))
+  }
+}
+
+enum SharedChangeTrackersKey: DependencyKey {
+  static var liveValue: LockIsolated<Set<SharedChangeTracker>> { LockIsolated([]) }
+  static var testValue: LockIsolated<Set<SharedChangeTracker>> {
+    LockIsolated([SharedChangeTracker()])
   }
 }
 
-@_spi(Internals) public enum SharedChangeTrackerKey: DependencyKey {
-  @_spi(Internals) public static var liveValue: SharedChangeTracker? { nil }
-  @_spi(Internals) public static var testValue: SharedChangeTracker? { SharedChangeTracker() }
+enum SharedChangeTrackerKey: DependencyKey {
+  static var liveValue: SharedChangeTracker? { nil }
+  static var testValue: SharedChangeTracker? { nil }
 }
diff --git a/Sources/ComposableArchitecture/TestStore.swift b/Sources/ComposableArchitecture/TestStore.swift
index 6258643666d8..9d072b6bd02a 100644
--- a/Sources/ComposableArchitecture/TestStore.swift
+++ b/Sources/ComposableArchitecture/TestStore.swift
@@ -490,6 +490,11 @@ public final class TestStore<State, Action> {
   private let file: StaticString
   private var line: UInt
   let reducer: TestReducer<State, Action>
+  private let sharedChangeTracker = {
+    @Dependency(SharedChangeTrackersKey.self)
+    var sharedChangeTrackers: LockIsolated<Set<SharedChangeTracker>>
+    return sharedChangeTrackers.first!
+  }()
   private let store: Store<State, TestReducer<State, Action>.TestAction>
 
   /// Creates a test store with an initial state and a reducer powering its runtime.
@@ -658,7 +663,7 @@ public final class TestStore<State, Action> {
         line: effect.action.line
       )
     }
-    self.dependencies[SharedChangeTrackerKey.self]?.assertUnchanged()
+    self.sharedChangeTracker.assertUnchanged()
   }
 
   /// Overrides the store's dependencies for a given operation.
@@ -957,19 +962,12 @@ extension TestStore where State: Equatable {
     file: StaticString,
     line: UInt
   ) throws {
-    let changeTracker = self.reducer.dependencies[SharedChangeTrackerKey.self]
-    try Dependencies.withDependencies {
-      $0[SharedChangeTrackerKey.self] = changeTracker
-    } operation: {
-      let wasAsserting = changeTracker?.isAsserting
-      changeTracker?.isAsserting = true
-      defer { changeTracker?.isAsserting = wasAsserting ?? false }
-
+    try self.sharedChangeTracker.assert {
       let skipUnnecessaryModifyFailure =
         skipUnnecessaryModifyFailure
-        || changeTracker?.hasChanges == true
+        ||  self.sharedChangeTracker.hasChanges == true
       if self.exhaustivity != .on {
-        changeTracker?.resetChanges()
+        self.sharedChangeTracker.resetChanges()
       }
 
       let current = expected
@@ -996,6 +994,7 @@ extension TestStore where State: Equatable {
         if let updateStateToExpectedResult {
           try Dependencies.withDependencies {
             $0 = self.reducer.dependencies
+            $0[SharedChangeTrackerKey.self] = self.sharedChangeTracker
           } operation: {
             try updateStateToExpectedResult(&expectedWhenGivenPreviousState)
           }
@@ -1013,6 +1012,7 @@ extension TestStore where State: Equatable {
         if let updateStateToExpectedResult {
           try Dependencies.withDependencies {
             $0 = self.reducer.dependencies
+            $0[SharedChangeTrackerKey.self] = self.sharedChangeTracker
           } operation: {
             try updateStateToExpectedResult(&expectedWhenGivenActualState)
           }
@@ -1032,6 +1032,7 @@ extension TestStore where State: Equatable {
               do {
                 try Dependencies.withDependencies {
                   $0 = self.reducer.dependencies
+                  $0[SharedChangeTrackerKey.self] = self.sharedChangeTracker
                 } operation: {
                   try updateStateToExpectedResult(&expectedWhenGivenPreviousState)
                 }
@@ -1104,7 +1105,7 @@ extension TestStore where State: Equatable {
           line: line
         )
       }
-      self.reducer.dependencies[SharedChangeTrackerKey.self]?.resetChanges()
+      self.sharedChangeTracker.resetChanges()
     }
   }
 }