diff --git a/DevCycle/Models/DVCConfig.swift b/DevCycle/Models/DVCConfig.swift
index 0993b1b..93c91e0 100644
--- a/DevCycle/Models/DVCConfig.swift
+++ b/DevCycle/Models/DVCConfig.swift
@@ -9,18 +9,34 @@ import Foundation
 public class DVCConfig {
     var sdkKey: String
     var user: DevCycleUser
+    private let userConfigQueue = DispatchQueue(
+        label: "com.devcycle.userConfig", attributes: .concurrent)
+    private var _userConfig: UserConfig?
+
     var userConfig: UserConfig? {
-        didSet {
-            if let userConfig = self.userConfig {
-                NotificationCenter.default.post(
-                    name: Notification.Name(NotificationNames.NewUserConfig),
-                    object: self,
-                    userInfo: ["new-user-config" : userConfig]
-                )
+        get {
+            return userConfigQueue.sync { _userConfig }
+        }
+        set {
+            // Synchronously set using a barrier to preserve existing semantics
+            userConfigQueue.async(flags: .barrier) {
+                self._userConfig = newValue
+                if let userConfig = newValue {
+                    DispatchQueue.main.async {
+                        NotificationCenter.default.post(
+                            name: Notification.Name(NotificationNames.NewUserConfig),
+                            object: self,
+                            userInfo: ["new-user-config": userConfig]
+                        )
+                    }
+                }
             }
+            // Fence: wait for the async barrier write above to complete so subsequent reads
+            // observe the new value immediately (mirrors original didSet synchronous behavior).
+            userConfigQueue.sync {}
         }
     }
-    
+
     init(sdkKey: String, user: DevCycleUser) {
         self.sdkKey = sdkKey
         self.user = user
diff --git a/DevCycleTests/Utils/GetTestConfig.swift b/DevCycleTests/Utils/GetTestConfig.swift
index 2fb771b..79f71f7 100644
--- a/DevCycleTests/Utils/GetTestConfig.swift
+++ b/DevCycleTests/Utils/GetTestConfig.swift
@@ -6,10 +6,18 @@
 //
 
 import Foundation
+import XCTest
 
 func getConfigData(name: String, withExtension: String = "json") -> Data {
-    let bundle = Bundle(for: DevCycleClientTest.self)
-    let fileUrl = bundle.url(forResource: name, withExtension: withExtension)
-    let data = try! Data(contentsOf: fileUrl!)
+    #if SWIFT_PACKAGE
+        let bundle = Bundle.module
+    #else
+        let bundle = Bundle(for: DevCycleClientTest.self)
+    #endif
+    guard let fileUrl = bundle.url(forResource: name, withExtension: withExtension) else {
+        XCTFail("Missing test resource: \(name).\(withExtension)")
+        return Data()
+    }
+    let data = try! Data(contentsOf: fileUrl)
     return data
 }
diff --git a/Package.swift b/Package.swift
index eb4be42..d3503b6 100644
--- a/Package.swift
+++ b/Package.swift
@@ -36,7 +36,11 @@ let package = Package(
             name: "DevCycleTests",
             dependencies: ["DevCycle"],
             path: "DevCycleTests",
-            exclude: ["ObjC"]
+            exclude: ["ObjC"],
+            resources: [
+                .process("Models/test_config.json"),
+                .process("Models/test_config_eval_reason.json"),
+            ]
         ),
         .testTarget(
             name: "DevCycleTests-ObjC",