diff --git a/Sources/Store/SerializableStore.swift b/Sources/Store/SerializableStore.swift
index 2ba0ae8..847cfbc 100644
--- a/Sources/Store/SerializableStore.swift
+++ b/Sources/Store/SerializableStore.swift
@@ -46,6 +46,7 @@ open class SerializableStore<M: Codable>: Store<M> {
   }
 
   override open func didUpdateModel(transaction: TransactionProtocol?, old: M, new: M) {
+    super.didUpdateModel(transaction: transaction, old: old, new: new)
     guard let transaction = transaction else {
       return
     }
@@ -87,6 +88,15 @@ open class SerializableStore<M: Codable>: Store<M> {
     }
   }
   
+  /// Creates a store for a subtree of the wrapped model.
+  /// Similar to Redux `combineStores`.
+  public func makeChildSerializableStore<M_1>(
+    keyPath: WritableKeyPath<M, M_1>,
+    create: (M_1) -> SerializableStore<M_1> = { SerializableStore<M_1>(model: $0) }
+  ) -> SerializableStore<M_1> {
+    super.makeChildStore(keyPath: keyPath, create: create) as! SerializableStore<M_1>
+  }
+  
   // MARK: - Model Encode/Decode
   
   /// Encodes the model into a dictionary.
diff --git a/Tests/StoreTests/CombinedStores.swift b/Tests/StoreTests/CombinedStores.swift
index ba3512a..4bc1a93 100644
--- a/Tests/StoreTests/CombinedStores.swift
+++ b/Tests/StoreTests/CombinedStores.swift
@@ -2,13 +2,13 @@ import XCTest
 import Combine
 @testable import Store
 
-struct Root {
-  struct Todo {
+struct Root: Codable {
+  struct Todo: Codable {
     var name: String = "Untitled"
     var description: String = "N/A"
     var done: Bool = false
   }
-  struct Note {
+  struct Note: Codable {
     var author: String = "Nobody"
     var text: String = ""
     var upvotes: Int = 0
@@ -19,19 +19,20 @@ struct Root {
   var list: [Todo] = []
 }
 
-class RootStore: Store<Root> {
+class RootStore: SerializableStore<Root> {
   // Children test.
-  lazy var todoStore = makeChildStore(keyPath: \.todo)
-  lazy var noteStore = makeChildStore(keyPath: \.note)
+  lazy var todoStore = makeChildSerializableStore(keyPath: \.todo)
+  lazy var noteStore = makeChildSerializableStore(keyPath: \.note)
 
   // List and transient store tests.
-  lazy var listStore = makeChildStore(keyPath: \.list)
+  lazy var listStore = makeChildSerializableStore(keyPath: \.list)
 }
 
 // MARK: Combined Stores
 
 extension Root.Todo {
   struct Action_MarkAsDone: ActionProtocol {
+    let id = "mark_as_done"
     func reduce(context: TransactionContext<Store<Root.Todo>, Self>) {
       defer { context.fulfill() }
       context.reduceModel { $0.done = true }
@@ -41,6 +42,7 @@ extension Root.Todo {
 
 extension Root.Note {
   struct Action_IncreaseUpvotes: ActionProtocol {
+    let id = "increase_upvotes"
     func reduce(context: TransactionContext<Store<Root.Note>, Self>) {
       defer { context.fulfill() }
       context.reduceModel { $0.upvotes += 1 }
@@ -52,6 +54,7 @@ extension Root.Note {
 
 extension Root.Todo {
   struct Action_ListCreateNew: ActionProtocol {
+    let id = "list_create_new"
     let name: String
     let description: String
     func reduce(context: TransactionContext<Store<Array<Root.Todo>>, Self>) {
@@ -73,6 +76,11 @@ final class CombinedStoreTests: XCTestCase {
   
   func testChildStoreChangesRootStoreValue() {
     let rootStore = RootStore(model: Root())
+    rootStore.register(middleware: LoggerMiddleware())
+    rootStore.todoStore.register(middleware: LoggerMiddleware())
+    rootStore.noteStore.register(middleware: LoggerMiddleware())
+    rootStore.listStore.register(middleware: LoggerMiddleware())
+
     XCTAssertFalse(rootStore.model.todo.done)
     XCTAssertFalse(rootStore.todoStore.model.done)
     rootStore.todoStore.run(action: Root.Todo.Action_MarkAsDone(), mode: .sync)
@@ -83,6 +91,11 @@ final class CombinedStoreTests: XCTestCase {
   func testChildStoreChangesTriggersRootObserver() {
     let observerExpectation = expectation(description: "Observer called.")
     let rootStore = RootStore(model: Root())
+    rootStore.register(middleware: LoggerMiddleware())
+    rootStore.todoStore.register(middleware: LoggerMiddleware())
+    rootStore.noteStore.register(middleware: LoggerMiddleware())
+    rootStore.listStore.register(middleware: LoggerMiddleware())
+    
     sink = rootStore.objectWillChange.sink {
       XCTAssertTrue(rootStore.model.todo.done)
       XCTAssertTrue(rootStore.todoStore.model.done)
@@ -99,6 +112,9 @@ final class CombinedStoreTests: XCTestCase {
     rootStore.listStore.run(
       action: Root.Todo.Action_ListCreateNew(name: "New", description: "New"),
       mode: .sync)
+    rootStore.register(middleware: LoggerMiddleware())
+    rootStore.listStore.register(middleware: LoggerMiddleware())
+    
     XCTAssertTrue(rootStore.listStore.model.count == 1)
     XCTAssertTrue(rootStore.listStore.model[0].name == "New")
     XCTAssertTrue(rootStore.listStore.model[0].description == "New")
@@ -108,7 +124,9 @@ final class CombinedStoreTests: XCTestCase {
     XCTAssertTrue(rootStore.model.list[0].description == "New")
     XCTAssertTrue(rootStore.model.list[0].done == false)
     
-    let todoStore: Store<Root.Todo> = rootStore.listStore.makeChildStore(keyPath: \.[0])
+    let todoStore: Store<Root.Todo> = rootStore.listStore.makeChildSerializableStore(keyPath: \.[0])
+    todoStore.register(middleware: LoggerMiddleware())
+
     todoStore.run(action: Root.Todo.Action_MarkAsDone(), mode: .sync)
     XCTAssertTrue(todoStore.model.name == "New")
     XCTAssertTrue(todoStore.model.description == "New")
diff --git a/Tests/StoreTests/Support/TestModel.swift b/Tests/StoreTests/Support/TestModel.swift
index 47c13b9..f0e1743 100644
--- a/Tests/StoreTests/Support/TestModel.swift
+++ b/Tests/StoreTests/Support/TestModel.swift
@@ -27,11 +27,11 @@ enum Action: ActionProtocol {
 
   var id: String {
     switch self {
-    case .increase(_): return "INCREASE"
-    case .throttleIncrease(_): return "THROTTLE_INCREASE"
-    case .decrease(_): return "DECREASE"
-    case .updateLabel(_): return "UPDATE_LABEL"
-    case .setArray(_): return "SET_ARRAY"
+    case .increase(_): return "increase"
+    case .throttleIncrease(_): return "throttle_increase"
+    case .decrease(_): return "decrease"
+    case .updateLabel(_): return "update_label"
+    case .setArray(_): return "set_array"
     }
   }