diff --git a/Sources/StreamCore/WebSocket/Client/WebSocketClient.swift b/Sources/StreamCore/WebSocket/Client/WebSocketClient.swift
index 299b5cb..73c0087 100644
--- a/Sources/StreamCore/WebSocket/Client/WebSocketClient.swift
+++ b/Sources/StreamCore/WebSocket/Client/WebSocketClient.swift
@@ -35,9 +35,14 @@ public class WebSocketClient: @unchecked Sendable {
 
     public weak var connectionStateDelegate: ConnectionStateDelegate?
 
-    public var connectRequest: URLRequest?
+    public var connectRequest: URLRequest? {
+        get { _connectRequest.value }
+        set { _connectRequest.value = newValue }
+    }
+    
+    private let _connectRequest = AllocatedUnfairLock<URLRequest?>(nil)
 
-    var requiresAuth: Bool
+    let requiresAuth: Bool
     /// If true, health check event is processed by the event notification center before setting connection status to connected, otherwise the order is reversed.
     /// Compatibility reasons for chat which has to set it to true.
     let healthCheckBeforeConnected: Bool
@@ -89,7 +94,7 @@ public class WebSocketClient: @unchecked Sendable {
         self.sessionConfiguration = sessionConfiguration
         self.webSocketClientType = webSocketClientType
         self.eventDecoder = eventDecoder
-        self.connectRequest = connectRequest
+        self._connectRequest.value = connectRequest
         self.eventNotificationCenter = eventNotificationCenter
         self.healthCheckBeforeConnected = healthCheckBeforeConnected
         self.requiresAuth = requiresAuth
@@ -123,7 +128,9 @@ public class WebSocketClient: @unchecked Sendable {
         }
 
         guard let connectRequest else { return }
-        engine = createEngineIfNeeded(for: connectRequest)
+        engineQueue.sync {
+            engine = createEngineIfNeeded(for: connectRequest)
+        }
 
         connectionState = .connecting
 
diff --git a/Tests/StreamCoreTests/Mocks/WebSocketPingController_Mock.swift b/Tests/StreamCoreTests/Mocks/WebSocketPingController_Mock.swift
index 0852118..deaec90 100644
--- a/Tests/StreamCoreTests/Mocks/WebSocketPingController_Mock.swift
+++ b/Tests/StreamCoreTests/Mocks/WebSocketPingController_Mock.swift
@@ -7,11 +7,11 @@ import Foundation
 import XCTest
 
 final class WebSocketPingController_Mock: WebSocketPingController, @unchecked Sendable {
-    var connectionStateDidChange_connectionStates: [WebSocketConnectionState] = []
-    var pongReceivedCount = 0
+    @Atomic var connectionStateDidChange_connectionStates: [WebSocketConnectionState] = []
+    @Atomic var pongReceivedCount = 0
 
     override func connectionStateDidChange(_ connectionState: WebSocketConnectionState) {
-        connectionStateDidChange_connectionStates.append(connectionState)
+        _connectionStateDidChange_connectionStates.mutate { $0.append(connectionState) }
         super.connectionStateDidChange(connectionState)
     }
 
diff --git a/Tests/StreamCoreTests/WebSockets/WebSocketClient/WebSocketClient_Tests.swift b/Tests/StreamCoreTests/WebSockets/WebSocketClient/WebSocketClient_Tests.swift
index 4d68471..3aba918 100644
--- a/Tests/StreamCoreTests/WebSockets/WebSocketClient/WebSocketClient_Tests.swift
+++ b/Tests/StreamCoreTests/WebSockets/WebSocketClient/WebSocketClient_Tests.swift
@@ -351,6 +351,15 @@ final class WebSocketClient_Tests: XCTestCase, @unchecked Sendable {
         // Assert completion called
         wait(for: [expectation], timeout: defaultTimeout)
     }
+    
+    func test_recreatingEngineConcurrently() {
+        DispatchQueue.concurrentPerform(iterations: 10000, execute: { _ in
+            guard let url = URL(string: "ws:///\(String.unique)") else { return }
+            self.webSocketClient.connectRequest = URLRequest(url: url)
+            self.webSocketClient.initialize()
+            self.webSocketClient.connect()
+        })
+    }
 }
 
 private final class HealthCheckEvent: @unchecked Sendable, Event, Codable, Hashable {