diff --git a/Sources/Packages/Package.swift b/Sources/Packages/Package.swift
index c5bc4c0..061f7ad 100644
--- a/Sources/Packages/Package.swift
+++ b/Sources/Packages/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version:5.5
+// swift-tools-version:5.9
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
@@ -33,23 +33,28 @@ let package = Package(
     targets: [
         .target(
             name: "SecretKit",
-            dependencies: []
+            dependencies: [],
+            swiftSettings: [.enableExperimentalFeature("StrictConcurrency"), .unsafeFlags(["-warnings-as-errors"])]
         ),
         .testTarget(
             name: "SecretKitTests",
-            dependencies: ["SecretKit", "SecureEnclaveSecretKit", "SmartCardSecretKit"]
+            dependencies: ["SecretKit", "SecureEnclaveSecretKit", "SmartCardSecretKit"],
+            swiftSettings: [.enableExperimentalFeature("StrictConcurrency"), .unsafeFlags(["-warnings-as-errors"])]
         ),
         .target(
             name: "SecureEnclaveSecretKit",
-            dependencies: ["SecretKit"]
+            dependencies: ["SecretKit"],
+            swiftSettings: [.enableExperimentalFeature("StrictConcurrency"), .unsafeFlags(["-warnings-as-errors"])]
         ),
         .target(
             name: "SmartCardSecretKit",
-            dependencies: ["SecretKit"]
+            dependencies: ["SecretKit"],
+            swiftSettings: [.enableExperimentalFeature("StrictConcurrency"), .unsafeFlags(["-warnings-as-errors"])]
         ),
         .target(
             name: "SecretAgentKit",
-            dependencies: ["SecretKit", "SecretAgentKitHeaders"]
+            dependencies: ["SecretKit", "SecretAgentKitHeaders"],
+            swiftSettings: [.enableExperimentalFeature("StrictConcurrency"), .unsafeFlags(["-warnings-as-errors"])]
         ),
         .systemLibrary(
             name: "SecretAgentKitHeaders"
diff --git a/Sources/Packages/Sources/Brief/Updater.swift b/Sources/Packages/Sources/Brief/Updater.swift
index c71e538..6c88d82 100644
--- a/Sources/Packages/Sources/Brief/Updater.swift
+++ b/Sources/Packages/Sources/Brief/Updater.swift
@@ -2,7 +2,7 @@ import Foundation
 import Combine
 
 /// A concrete implementation of ``UpdaterProtocol`` which considers the current release and OS version.
-public class Updater: ObservableObject, UpdaterProtocol {
+public final class Updater: ObservableObject, UpdaterProtocol {
 
     @Published public var update: Release?
     public let testBuild: Bool
diff --git a/Sources/Packages/Sources/SecretAgentKit/Agent.swift b/Sources/Packages/Sources/SecretAgentKit/Agent.swift
index abee4dd..ed1654b 100644
--- a/Sources/Packages/Sources/SecretAgentKit/Agent.swift
+++ b/Sources/Packages/Sources/SecretAgentKit/Agent.swift
@@ -5,7 +5,7 @@ import SecretKit
 import AppKit
 
 /// The `Agent` is an implementation of an SSH agent. It manages coordination and access between a socket, traces requests, notifies witnesses and passes requests to stores.
-public class Agent {
+public final class Agent {
 
     private let storeList: SecretStoreList
     private let witness: SigningWitness?
diff --git a/Sources/Packages/Sources/SecretAgentKit/Sendability.swift b/Sources/Packages/Sources/SecretAgentKit/Sendability.swift
new file mode 100644
index 0000000..5338464
--- /dev/null
+++ b/Sources/Packages/Sources/SecretAgentKit/Sendability.swift
@@ -0,0 +1,11 @@
+import Foundation
+
+struct UncheckedSendable<T>: @unchecked Sendable {
+
+    let value: T
+
+    init(_ value: T) {
+        self.value = value
+    }
+
+}
diff --git a/Sources/Packages/Sources/SecretAgentKit/SocketController.swift b/Sources/Packages/Sources/SecretAgentKit/SocketController.swift
index 43243db..a51951f 100644
--- a/Sources/Packages/Sources/SecretAgentKit/SocketController.swift
+++ b/Sources/Packages/Sources/SecretAgentKit/SocketController.swift
@@ -2,7 +2,7 @@ import Foundation
 import OSLog
 
 /// A controller that manages socket configuration and request dispatching.
-public class SocketController {
+public final class SocketController {
 
     /// The active FileHandle.
     private var fileHandle: FileHandle?
@@ -10,7 +10,7 @@ public class SocketController {
     private var port: SocketPort?
     /// A handler that will be notified when a new read/write handle is available.
     /// False if no data could be read
-    public var handler: ((FileHandleReader, FileHandleWriter) async -> Bool)?
+    public var handler: (@Sendable (FileHandleReader, FileHandleWriter) async -> Bool)?
     /// Logger.
     private let logger = Logger(subsystem: "com.maxgoedjen.secretive.secretagent", category: "SocketController")
 
@@ -69,7 +69,7 @@ public class SocketController {
     @objc func handleConnectionAccept(notification: Notification) {
         logger.debug("Socket controller accepted connection")
         guard let new = notification.userInfo?[NSFileHandleNotificationFileHandleItem] as? FileHandle else { return }
-        Task {
+        Task { [handler, fileHandle] in
             _ = await handler?(new, new)
             await new.waitForDataInBackgroundAndNotifyOnMainActor()
             await fileHandle?.acceptConnectionInBackgroundAndNotifyOnMainActor()
@@ -82,12 +82,12 @@ public class SocketController {
         logger.debug("Socket controller has new data available")
         guard let new = notification.object as? FileHandle else { return }
         logger.debug("Socket controller received new file handle")
-        Task {
+        Task { [handler, logger = UncheckedSendable(logger)] in
             if((await handler?(new, new)) == true) {
-                logger.debug("Socket controller handled data, wait for more data")
+                logger.value.debug("Socket controller handled data, wait for more data")
                 await new.waitForDataInBackgroundAndNotifyOnMainActor()
             } else {
-                logger.debug("Socket controller called with empty data, socked closed")
+                logger.value.debug("Socket controller called with empty data, socked closed")
             }
         }
     }
diff --git a/Sources/Packages/Sources/SecretKit/Erasers/AnySecretStore.swift b/Sources/Packages/Sources/SecretKit/Erasers/AnySecretStore.swift
index f70000b..bf5a74d 100644
--- a/Sources/Packages/Sources/SecretKit/Erasers/AnySecretStore.swift
+++ b/Sources/Packages/Sources/SecretKit/Erasers/AnySecretStore.swift
@@ -71,7 +71,7 @@ public class AnySecretStore: SecretStore {
 
 }
 
-public class AnySecretStoreModifiable: AnySecretStore, SecretStoreModifiable {
+public final class AnySecretStoreModifiable: AnySecretStore, SecretStoreModifiable {
 
     private let _create: (String, Bool) throws -> Void
     private let _delete: (AnySecret) throws -> Void
diff --git a/Sources/Packages/Sources/SecretKit/OpenSSH/OpenSSHCertificateHandler.swift b/Sources/Packages/Sources/SecretKit/OpenSSH/OpenSSHCertificateHandler.swift
index 12ecefa..5066545 100644
--- a/Sources/Packages/Sources/SecretKit/OpenSSH/OpenSSHCertificateHandler.swift
+++ b/Sources/Packages/Sources/SecretKit/OpenSSH/OpenSSHCertificateHandler.swift
@@ -2,7 +2,7 @@ import Foundation
 import OSLog
 
 /// Manages storage and lookup for OpenSSH certificates.
-public class OpenSSHCertificateHandler {
+public final class OpenSSHCertificateHandler {
 
     private let publicKeyFileStoreController = PublicKeyFileStoreController(homeDirectory: NSHomeDirectory())
     private let logger = Logger(subsystem: "com.maxgoedjen.secretive.secretagent", category: "OpenSSHCertificateHandler")
diff --git a/Sources/Packages/Sources/SecretKit/OpenSSH/OpenSSHReader.swift b/Sources/Packages/Sources/SecretKit/OpenSSH/OpenSSHReader.swift
index 027b63d..6b7bc08 100644
--- a/Sources/Packages/Sources/SecretKit/OpenSSH/OpenSSHReader.swift
+++ b/Sources/Packages/Sources/SecretKit/OpenSSH/OpenSSHReader.swift
@@ -1,7 +1,7 @@
 import Foundation
 
 /// Reads OpenSSH protocol data.
-public class OpenSSHReader {
+public final class OpenSSHReader {
 
     var remaining: Data
 
diff --git a/Sources/Packages/Sources/SecretKit/PublicKeyStandinFileController.swift b/Sources/Packages/Sources/SecretKit/PublicKeyStandinFileController.swift
index 7ec0a62..7c3f8da 100644
--- a/Sources/Packages/Sources/SecretKit/PublicKeyStandinFileController.swift
+++ b/Sources/Packages/Sources/SecretKit/PublicKeyStandinFileController.swift
@@ -2,7 +2,7 @@ import Foundation
 import OSLog
 
 /// Controller responsible for writing public keys to disk, so that they're easily accessible by scripts.
-public class PublicKeyFileStoreController {
+public final class PublicKeyFileStoreController {
 
     private let logger = Logger(subsystem: "com.maxgoedjen.secretive.secretagent", category: "PublicKeyFileStoreController")
     private let directory: String
diff --git a/Sources/Packages/Sources/SecretKit/SecretStoreList.swift b/Sources/Packages/Sources/SecretKit/SecretStoreList.swift
index 1345d56..eb8456f 100644
--- a/Sources/Packages/Sources/SecretKit/SecretStoreList.swift
+++ b/Sources/Packages/Sources/SecretKit/SecretStoreList.swift
@@ -2,7 +2,7 @@ import Foundation
 import Combine
 
 /// A "Store Store," which holds a list of type-erased stores.
-public class SecretStoreList: ObservableObject {
+public final class SecretStoreList: ObservableObject {
 
     /// The Stores managed by the SecretStoreList.
     @Published public var stores: [AnySecretStore] = []
diff --git a/Sources/Packages/Sources/SecureEnclaveSecretKit/SecureEnclaveStore.swift b/Sources/Packages/Sources/SecureEnclaveSecretKit/SecureEnclaveStore.swift
index 5a853c4..75935c1 100644
--- a/Sources/Packages/Sources/SecureEnclaveSecretKit/SecureEnclaveStore.swift
+++ b/Sources/Packages/Sources/SecureEnclaveSecretKit/SecureEnclaveStore.swift
@@ -8,7 +8,7 @@ import SecretKit
 extension SecureEnclave {
 
     /// An implementation of Store backed by the Secure Enclave.
-    public class Store: SecretStoreModifiable {
+    public final class Store: SecretStoreModifiable {
 
         public var isAvailable: Bool {
             // For some reason, as of build time, CryptoKit.SecureEnclave.isAvailable always returns false
@@ -24,8 +24,8 @@ extension SecureEnclave {
 
         /// Initializes a Store.
         public init() {
-            DistributedNotificationCenter.default().addObserver(forName: .secretStoreUpdated, object: nil, queue: .main) { _ in
-                self.reloadSecretsInternal(notifyAgent: false)
+            DistributedNotificationCenter.default().addObserver(forName: .secretStoreUpdated, object: nil, queue: .main) { [reload = reloadSecretsInternal(notifyAgent:)] _ in
+                reload(false)
             }
             loadSecrets()
         }
@@ -211,7 +211,7 @@ extension SecureEnclave.Store {
 
     /// Reloads all secrets from the store.
     /// - Parameter notifyAgent: A boolean indicating whether a distributed notification should be posted, notifying other processes (ie, the SecretAgent) to reload their stores as well.
-    private func reloadSecretsInternal(notifyAgent: Bool = true) {
+    @Sendable private func reloadSecretsInternal(notifyAgent: Bool = true) {
         let before = secrets
         secrets.removeAll()
         loadSecrets()
diff --git a/Sources/Packages/Sources/SmartCardSecretKit/SmartCardStore.swift b/Sources/Packages/Sources/SmartCardSecretKit/SmartCardStore.swift
index 6d999ac..dd52d22 100644
--- a/Sources/Packages/Sources/SmartCardSecretKit/SmartCardStore.swift
+++ b/Sources/Packages/Sources/SmartCardSecretKit/SmartCardStore.swift
@@ -8,7 +8,7 @@ import SecretKit
 extension SmartCard {
 
     /// An implementation of Store backed by a Smart Card.
-    public class Store: SecretStore {
+    public final class Store: SecretStore {
 
         @Published public var isAvailable: Bool = false
         public let id = UUID()
@@ -20,12 +20,14 @@ extension SmartCard {
         /// Initializes a Store.
         public init() {
             tokenID = watcher.nonSecureEnclaveTokens.first
-            watcher.setInsertionHandler { string in
+            watcher.setInsertionHandler { [reload = reloadSecretsInternal] string in
                 guard self.tokenID == nil else { return }
                 guard !string.contains("setoken") else { return }
 
                 self.tokenID = string
-                self.reloadSecrets()
+                DispatchQueue.main.async {
+                    reload()
+                }
                 self.watcher.addRemovalHandler(self.smartcardRemoved, forTokenID: string)
             }
             if let tokenID = tokenID {
@@ -106,15 +108,7 @@ extension SmartCard {
 
         /// Reloads all secrets from the store.
         public func reloadSecrets() {
-            DispatchQueue.main.async {
-                self.isAvailable = self.tokenID != nil
-                let before = self.secrets
-                self.secrets.removeAll()
-                self.loadSecrets()
-                if self.secrets != before {
-                    NotificationCenter.default.post(name: .secretStoreReloaded, object: self)
-                }
-            }
+            reloadSecretsInternal()
         }
 
     }
@@ -123,6 +117,16 @@ extension SmartCard {
 
 extension SmartCard.Store {
 
+    @Sendable private func reloadSecretsInternal() {
+        self.isAvailable = self.tokenID != nil
+        let before = self.secrets
+        self.secrets.removeAll()
+        self.loadSecrets()
+        if self.secrets != before {
+            NotificationCenter.default.post(name: .secretStoreReloaded, object: self)
+        }
+    }
+
     /// Resets the token ID and reloads secrets.
     /// - Parameter tokenID: The ID of the token that was removed.
     private func smartcardRemoved(for tokenID: String? = nil) {
diff --git a/Sources/Packages/Tests/SecretAgentKitTests/StubStore.swift b/Sources/Packages/Tests/SecretAgentKitTests/StubStore.swift
index f155706..f990f97 100644
--- a/Sources/Packages/Tests/SecretAgentKitTests/StubStore.swift
+++ b/Sources/Packages/Tests/SecretAgentKitTests/StubStore.swift
@@ -6,7 +6,7 @@ struct Stub {}
 
 extension Stub {
 
-    public class Store: SecretStore {
+    public final class Store: SecretStore {
 
         public let isAvailable = true
         public let id = UUID()
diff --git a/Sources/Secretive.xcodeproj/project.pbxproj b/Sources/Secretive.xcodeproj/project.pbxproj
index fe78151..0eb5b4d 100644
--- a/Sources/Secretive.xcodeproj/project.pbxproj
+++ b/Sources/Secretive.xcodeproj/project.pbxproj
@@ -3,7 +3,7 @@
 	archiveVersion = 1;
 	classes = {
 	};
-	objectVersion = 52;
+	objectVersion = 54;
 	objects = {
 
 /* Begin PBXBuildFile section */
@@ -691,6 +691,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = com.maxgoedjen.Secretive.Host;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE_SPECIFIER = "";
+				SWIFT_STRICT_CONCURRENCY = complete;
 				SWIFT_VERSION = 5.0;
 			};
 			name = Debug;
@@ -718,6 +719,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = com.maxgoedjen.Secretive.Host;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE_SPECIFIER = "Secretive - Host";
+				SWIFT_STRICT_CONCURRENCY = complete;
 				SWIFT_VERSION = 5.0;
 			};
 			name = Release;
@@ -848,6 +850,7 @@
 				MARKETING_VERSION = 1;
 				PRODUCT_BUNDLE_IDENTIFIER = com.maxgoedjen.Secretive.Host;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_STRICT_CONCURRENCY = complete;
 				SWIFT_VERSION = 5.0;
 			};
 			name = Test;
@@ -891,6 +894,7 @@
 				MARKETING_VERSION = 1;
 				PRODUCT_BUNDLE_IDENTIFIER = com.maxgoedjen.Secretive.SecretAgent;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_STRICT_CONCURRENCY = complete;
 				SWIFT_VERSION = 5.0;
 			};
 			name = Test;
@@ -914,6 +918,7 @@
 				MARKETING_VERSION = 1;
 				PRODUCT_BUNDLE_IDENTIFIER = com.maxgoedjen.Secretive.SecretAgent;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_STRICT_CONCURRENCY = complete;
 				SWIFT_VERSION = 5.0;
 			};
 			name = Debug;
@@ -939,6 +944,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = com.maxgoedjen.Secretive.SecretAgent;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE_SPECIFIER = "Secretive - Secret Agent";
+				SWIFT_STRICT_CONCURRENCY = complete;
 				SWIFT_VERSION = 5.0;
 			};
 			name = Release;