diff --git a/Sources/APNS/APNSClient.swift b/Sources/APNS/APNSClient.swift
index a1c3826..2e648ed 100644
--- a/Sources/APNS/APNSClient.swift
+++ b/Sources/APNS/APNSClient.swift
@@ -125,7 +125,7 @@ public final class APNSClient<Decoder: APNSJSONDecoder, Encoder: APNSJSONEncoder
     /// - Parameters:
     ///   - queue: The queue on which the callback is invoked on.
     ///   - callback: The callback that is invoked when everything is shutdown.
-    public func shutdown(queue: DispatchQueue = .global(), callback: @escaping (Error?) -> Void) {
+    @preconcurrency public func shutdown(queue: DispatchQueue = .global(), callback: @Sendable @escaping (Error?) -> Void) {
         self.httpClient.shutdown(callback)
     }
 
diff --git a/Sources/APNS/APNSConfiguration.swift b/Sources/APNS/APNSConfiguration.swift
index c2392a8..ba62c6d 100644
--- a/Sources/APNS/APNSConfiguration.swift
+++ b/Sources/APNS/APNSConfiguration.swift
@@ -13,7 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 import APNSCore
-import Crypto
+@preconcurrency import Crypto
 import NIOSSL
 import NIOTLS
 import AsyncHTTPClient
@@ -22,7 +22,7 @@ import AsyncHTTPClient
 public struct APNSClientConfiguration: Sendable {
     /// The authentication method used by the ``APNSClient``.
     public struct AuthenticationMethod: Sendable {
-        internal enum Method {
+        internal enum Method : Sendable{
             case jwt(privateKey: P256.Signing.PrivateKey, teamIdentifier: String, keyIdentifier: String)
             case tls(privateKey: NIOSSLPrivateKeySource, certificateChain: [NIOSSLCertificateSource])
         }
diff --git a/Sources/APNSCore/APNSError.swift b/Sources/APNSCore/APNSError.swift
index 41bd2c6..4a7c0b6 100644
--- a/Sources/APNSCore/APNSError.swift
+++ b/Sources/APNSCore/APNSError.swift
@@ -21,8 +21,8 @@ public struct APNSError: Error {
     /// The error reason returned by APNs.
     ///
     /// For more information please look here: [Reference]( https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/handling_notification_responses_from_apns)
-    public struct ErrorReason: Hashable {
-        public enum Reason: RawRepresentable, Hashable {
+    public struct ErrorReason: Hashable, Sendable {
+        public enum Reason: RawRepresentable, Hashable, Sendable {
             public typealias RawValue = String
 
             case badCollapseIdentifier
diff --git a/Sources/APNSCore/Base64.swift b/Sources/APNSCore/Base64.swift
index 46bd3f2..c78fa67 100644
--- a/Sources/APNSCore/Base64.swift
+++ b/Sources/APNSCore/Base64.swift
@@ -89,7 +89,7 @@ internal enum Base64 {}
 
 extension Base64 {
     @usableFromInline
-    internal struct EncodingOptions: OptionSet {
+    internal struct EncodingOptions: OptionSet, Sendable {
         @usableFromInline
         internal let rawValue: UInt
 
@@ -557,7 +557,7 @@ extension Base64 {
 
 extension Base64 {
     @usableFromInline
-    internal struct DecodingOptions: OptionSet {
+    internal struct DecodingOptions: OptionSet, Sendable {
         @usableFromInline
         internal let rawValue: UInt
 
diff --git a/Sources/APNSCore/LiveActivity/APNSLiveActivityDismissalDate.swift b/Sources/APNSCore/LiveActivity/APNSLiveActivityDismissalDate.swift
index cb1112d..9bd7d4e 100644
--- a/Sources/APNSCore/LiveActivity/APNSLiveActivityDismissalDate.swift
+++ b/Sources/APNSCore/LiveActivity/APNSLiveActivityDismissalDate.swift
@@ -14,7 +14,7 @@
 
 import struct Foundation.Date
 
-public struct APNSLiveActivityDismissalDate: Hashable {
+public struct APNSLiveActivityDismissalDate: Hashable, Sendable {
     /// The date at which the live activity will be dismissed
     /// This value is a UNIX epoch expressed in seconds (UTC)
     @usableFromInline
diff --git a/Sources/APNSCore/LiveActivity/APNSLiveActivityNotification.swift b/Sources/APNSCore/LiveActivity/APNSLiveActivityNotification.swift
index 135a193..358d16b 100644
--- a/Sources/APNSCore/LiveActivity/APNSLiveActivityNotification.swift
+++ b/Sources/APNSCore/LiveActivity/APNSLiveActivityNotification.swift
@@ -17,7 +17,7 @@ import struct Foundation.UUID
 /// A live activity notification.
 ///
 /// It is **important** that you do not encode anything with the key `aps`.
-public struct APNSLiveActivityNotification<ContentState: Encodable>: APNSMessage {
+public struct APNSLiveActivityNotification<ContentState: Encodable & Sendable>: APNSMessage {
     enum CodingKeys: CodingKey {
         case aps
     }
diff --git a/Sources/APNSCore/LiveActivity/APNSLiveActivityNotificationAPSStorage.swift b/Sources/APNSCore/LiveActivity/APNSLiveActivityNotificationAPSStorage.swift
index 756c747..7bde976 100644
--- a/Sources/APNSCore/LiveActivity/APNSLiveActivityNotificationAPSStorage.swift
+++ b/Sources/APNSCore/LiveActivity/APNSLiveActivityNotificationAPSStorage.swift
@@ -12,7 +12,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-struct APNSLiveActivityNotificationAPSStorage<ContentState: Encodable>: Encodable {
+struct APNSLiveActivityNotificationAPSStorage<ContentState: Encodable & Sendable>: Encodable {
     enum CodingKeys: String, CodingKey {
         case timestamp = "timestamp"
         case event = "event"
diff --git a/Sources/APNSCore/LiveActivity/APNSLiveActivityNotificationEvent.swift b/Sources/APNSCore/LiveActivity/APNSLiveActivityNotificationEvent.swift
index 9f925f8..b0f6ca2 100644
--- a/Sources/APNSCore/LiveActivity/APNSLiveActivityNotificationEvent.swift
+++ b/Sources/APNSCore/LiveActivity/APNSLiveActivityNotificationEvent.swift
@@ -12,7 +12,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-public struct APNSLiveActivityNotificationEvent: Hashable {
+public struct APNSLiveActivityNotificationEvent: Hashable, Sendable {
     /// The underlying raw value that is send to APNs.
     @usableFromInline
     internal let rawValue: String
diff --git a/Sources/APNSCore/LiveActivity/APNSStartLiveActivityNotification.swift b/Sources/APNSCore/LiveActivity/APNSStartLiveActivityNotification.swift
index 4a72246..0c5c9d2 100644
--- a/Sources/APNSCore/LiveActivity/APNSStartLiveActivityNotification.swift
+++ b/Sources/APNSCore/LiveActivity/APNSStartLiveActivityNotification.swift
@@ -17,7 +17,7 @@ import struct Foundation.UUID
 /// A notification that starts a live activity
 ///
 /// It is **important** that you do not encode anything with the key `aps`.
-public struct APNSStartLiveActivityNotification<Attributes: Encodable, ContentState: Encodable>:
+public struct APNSStartLiveActivityNotification<Attributes: Encodable & Sendable, ContentState: Encodable & Sendable>:
     APNSMessage
 {
     enum CodingKeys: CodingKey {
diff --git a/Sources/APNSCore/LiveActivity/APNSStartLiveActivityNotificationAPSStorage.swift b/Sources/APNSCore/LiveActivity/APNSStartLiveActivityNotificationAPSStorage.swift
index 2fd1947..58ddb35 100644
--- a/Sources/APNSCore/LiveActivity/APNSStartLiveActivityNotificationAPSStorage.swift
+++ b/Sources/APNSCore/LiveActivity/APNSStartLiveActivityNotificationAPSStorage.swift
@@ -12,8 +12,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-struct APNSStartLiveActivityNotificationAPSStorage<Attributes: Encodable, ContentState: Encodable>:
-    Encodable
+struct APNSStartLiveActivityNotificationAPSStorage<Attributes: Encodable & Sendable, ContentState: Encodable & Sendable>:
+    Encodable & Sendable
 {
     enum CodingKeys: String, CodingKey {
         case timestamp = "timestamp"
diff --git a/Sources/APNSURLSession/APNSURLSessionClientConfiguration.swift b/Sources/APNSURLSession/APNSURLSessionClientConfiguration.swift
index e89dae9..501a6cc 100644
--- a/Sources/APNSURLSession/APNSURLSessionClientConfiguration.swift
+++ b/Sources/APNSURLSession/APNSURLSessionClientConfiguration.swift
@@ -13,7 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 import APNSCore
-import Crypto
+@preconcurrency import Crypto
 
 /// The configuration of an ``APNSURLSessionClient``.
 public struct APNSURLSessionClientConfiguration {