diff --git a/.vscode/launch.json b/.vscode/launch.json
index 7591523d..9cda9402 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -6,7 +6,7 @@
       "type": "coreclr",
       "request": "launch",
       "preLaunchTask": "build",
-      "program": "${workspaceRoot}/src/ApplePayJS/bin/Debug/net8.0/JustEat.ApplePayJS.dll",
+      "program": "${workspaceRoot}/src/ApplePayJS/bin/Debug/net9.0/JustEat.ApplePayJS.dll",
       "args": [],
       "cwd": "${workspaceRoot}/src/ApplePayJS",
       "stopAtEntry": false,
diff --git a/Directory.Build.props b/Directory.Build.props
index eb2fc0cb..f2729fd0 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -15,7 +15,7 @@
     <RepositoryType>git</RepositoryType>
     <RepositoryUrl>$(PackageProjectUrl).git</RepositoryUrl>
     <TypeScriptToolsVersion>latest</TypeScriptToolsVersion>
-    <VersionPrefix>8.0.0</VersionPrefix>
+    <VersionPrefix>9.0.0</VersionPrefix>
     <VersionSuffix></VersionSuffix>
   </PropertyGroup>
 </Project>
diff --git a/global.json b/global.json
index c8aeb425..0122a333 100644
--- a/global.json
+++ b/global.json
@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "8.0.404",
+    "version": "9.0.100",
     "allowPrerelease": false
   }
 }
diff --git a/src/ApplePayJS/ApplePayJS.csproj b/src/ApplePayJS/ApplePayJS.csproj
index d6413004..f668e407 100644
--- a/src/ApplePayJS/ApplePayJS.csproj
+++ b/src/ApplePayJS/ApplePayJS.csproj
@@ -12,7 +12,7 @@
     <PackageTags>applepay</PackageTags>
     <PreserveCompilationContext>true</PreserveCompilationContext>
     <RootNamespace>JustEat.ApplePayJS</RootNamespace>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <TypeScriptToolsVersion>latest</TypeScriptToolsVersion>
     <UserSecretsId>JustEat.ApplePayJS</UserSecretsId>
   </PropertyGroup>
diff --git a/src/ApplePayJS/Clients/MerchantCertificate.cs b/src/ApplePayJS/Clients/MerchantCertificate.cs
index 28a8a5f2..47d6e371 100644
--- a/src/ApplePayJS/Clients/MerchantCertificate.cs
+++ b/src/ApplePayJS/Clients/MerchantCertificate.cs
@@ -62,7 +62,7 @@ private static X509Certificate2 LoadCertificateFromBase64String(string encoded,
 
         return X509Certificate2.GetCertContentType(rawData) switch
         {
-            X509ContentType.Pfx => new X509Certificate2(rawData, password),
+            X509ContentType.Pfx => X509CertificateLoader.LoadPkcs12(rawData, password),
             _ => throw new NotSupportedException("The format of the encoded Apple Pay merchant certificate is not supported."),
         };
     }
@@ -71,7 +71,7 @@ private static X509Certificate2 LoadCertificateFromDisk(string? fileName, string
     {
         try
         {
-            return new X509Certificate2(
+            return X509CertificateLoader.LoadPkcs12FromFile(
                 fileName ?? string.Empty,
                 password);
         }
diff --git a/src/ApplePayJS/package-lock.json b/src/ApplePayJS/package-lock.json
index e47361a4..c320f908 100644
--- a/src/ApplePayJS/package-lock.json
+++ b/src/ApplePayJS/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "justeatapplepayjs",
-  "version": "8.0.0",
+  "version": "9.0.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
diff --git a/src/ApplePayJS/package.json b/src/ApplePayJS/package.json
index def338d4..d9bcdaac 100644
--- a/src/ApplePayJS/package.json
+++ b/src/ApplePayJS/package.json
@@ -1,7 +1,7 @@
 {
   "name": "justeatapplepayjs",
   "private": true,
-  "version": "8.0.0",
+  "version": "9.0.0",
   "devDependencies": {
     "@types/applepayjs": "3.0.0",
     "@types/jquery": "3.3.34",
diff --git a/tests/ApplePayJS.Tests/ApplePayJS.Tests.csproj b/tests/ApplePayJS.Tests/ApplePayJS.Tests.csproj
index 0a008a25..43828a8a 100644
--- a/tests/ApplePayJS.Tests/ApplePayJS.Tests.csproj
+++ b/tests/ApplePayJS.Tests/ApplePayJS.Tests.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
   <ItemGroup>
@@ -11,7 +11,7 @@
     <PackageReference Include="GitHubActionsTestLogger" Version="2.4.1" />
     <PackageReference Include="JustEat.HttpClientInterception" Version="4.3.0" />
     <PackageReference Include="MartinCostello.Logging.XUnit" Version="0.4.0" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="8.0.10" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="9.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
     <PackageReference Include="Microsoft.Playwright" Version="1.48.0" />
     <PackageReference Include="Shouldly" Version="4.2.1" />
diff --git a/tests/ApplePayJS.Tests/TestFixture.cs b/tests/ApplePayJS.Tests/TestFixture.cs
index e51f8dfc..e9c1df71 100644
--- a/tests/ApplePayJS.Tests/TestFixture.cs
+++ b/tests/ApplePayJS.Tests/TestFixture.cs
@@ -64,7 +64,7 @@ protected override void ConfigureWebHost(IWebHostBuilder builder)
 
         builder.ConfigureKestrel(
             (kestrelOptions) => kestrelOptions.ConfigureHttpsDefaults(
-                (connectionOptions) => connectionOptions.ServerCertificate = new X509Certificate2("localhost-dev.pfx", "Pa55w0rd!")));
+                (connectionOptions) => connectionOptions.ServerCertificate = X509CertificateLoader.LoadPkcs12FromFile("localhost-dev.pfx", "Pa55w0rd!")));
 
         // Configure the server address for the server to listen on for HTTP requests
         builder.UseUrls("https://127.0.0.1:0");