diff --git a/Sources/TelemetryDeck/Signals/SignalManager.swift b/Sources/TelemetryDeck/Signals/SignalManager.swift
index 2dad01f..bf80dfa 100644
--- a/Sources/TelemetryDeck/Signals/SignalManager.swift
+++ b/Sources/TelemetryDeck/Signals/SignalManager.swift
@@ -13,6 +13,8 @@ import TVUIKit
 protocol SignalManageable {
     func processSignal(_ signalName: String, parameters: [String: String], floatValue: Double?, customUserID: String?, configuration: TelemetryManagerConfiguration)
     func attemptToSendNextBatchOfCachedSignals()
+
+    @MainActor var defaultUserIdentifier: String { get }
 }
 
 final class SignalManager: SignalManageable, @unchecked Sendable {
@@ -237,7 +239,7 @@ private extension SignalManager {
 
 // MARK: - Helpers
 
-private extension SignalManager {
+extension SignalManager {
     #if os(macOS)
     /// A custom ``UserDefaults`` instance specific to TelemetryDeck and the current application.
     private var customDefaults: UserDefaults? {
diff --git a/Sources/TelemetryDeck/TelemetryClient.swift b/Sources/TelemetryDeck/TelemetryClient.swift
index e168268..cd0b052 100644
--- a/Sources/TelemetryDeck/TelemetryClient.swift
+++ b/Sources/TelemetryDeck/TelemetryClient.swift
@@ -259,8 +259,9 @@ public final class TelemetryManager: @unchecked Sendable {
         TelemetryDeck.updateDefaultUserID(to: newDefaultUser)
     }
 
-    public var hashedDefaultUser: String? {
-        guard let defaultUser = configuration.defaultUser else { return nil }
+    @MainActor
+    public var hashedDefaultUser: String {
+        let defaultUser = self.signalManager.defaultUserIdentifier
         return CryptoHashing.sha256(string: defaultUser, salt: configuration.salt)
     }
 
diff --git a/Tests/TelemetryDeckTests/TelemetryDeckTests.swift b/Tests/TelemetryDeckTests/TelemetryDeckTests.swift
index 506d3c8..4466973 100644
--- a/Tests/TelemetryDeckTests/TelemetryDeckTests.swift
+++ b/Tests/TelemetryDeckTests/TelemetryDeckTests.swift
@@ -64,7 +64,7 @@ struct TelemetryDeckTests {
             }
         }
         
-        var configuration = TelemetryManagerConfiguration(appID: UUID().uuidString)
+        let configuration = TelemetryManagerConfiguration(appID: UUID().uuidString)
         configuration.metadataEnrichers.append(BasicEnricher())
         
         let signalManager = FakeSignalManager()
@@ -85,7 +85,7 @@ struct TelemetryDeckTests {
             }
         }
         
-        var configuration = TelemetryManagerConfiguration(appID: UUID().uuidString)
+        let configuration = TelemetryManagerConfiguration(appID: UUID().uuidString)
         configuration.metadataEnrichers.append(BasicEnricher())
         
         let signalManager = FakeSignalManager()
@@ -117,7 +117,7 @@ struct TelemetryDeckTests {
     func sendsSignals_withAnalyticsExplicitlyEnabled() {
         let YOUR_APP_ID = "44e0f59a-60a2-4d4a-bf27-1f96ccb4aaa3"
 
-        var configuration = TelemetryManagerConfiguration(appID: YOUR_APP_ID)
+        let configuration = TelemetryManagerConfiguration(appID: YOUR_APP_ID)
         configuration.analyticsDisabled = false
         
         let signalManager = FakeSignalManager()
@@ -132,7 +132,7 @@ struct TelemetryDeckTests {
     func doesNotSendSignals_withAnalyticsExplicitlyDisabled() {
         let YOUR_APP_ID = "44e0f59a-60a2-4d4a-bf27-1f96ccb4aaa3"
 
-        var configuration = TelemetryManagerConfiguration(appID: YOUR_APP_ID)
+        let configuration = TelemetryManagerConfiguration(appID: YOUR_APP_ID)
         configuration.analyticsDisabled = true
         
         let signalManager = FakeSignalManager()
@@ -149,7 +149,7 @@ struct TelemetryDeckTests {
 
         let YOUR_APP_ID = "44e0f59a-60a2-4d4a-bf27-1f96ccb4aaa3"
 
-        var configuration = TelemetryManagerConfiguration(appID: YOUR_APP_ID)
+        let configuration = TelemetryManagerConfiguration(appID: YOUR_APP_ID)
         configuration.analyticsDisabled = false
         
         let signalManager = FakeSignalManager()
@@ -206,4 +206,6 @@ private class FakeSignalManager: @preconcurrency SignalManageable {
     }
 
     func attemptToSendNextBatchOfCachedSignals() {}
+
+    var defaultUserIdentifier: String { UUID().uuidString }
 }