diff --git a/.vscode/launch.json b/.vscode/launch.json
index a51d215a..7919da9c 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -6,7 +6,7 @@
       "type": "coreclr",
       "request": "launch",
       "preLaunchTask": "build",
-      "program": "${workspaceRoot}/src/ApplePayJS/bin/Debug/netcoreapp3.1/JustEat.ApplePayJS.dll",
+      "program": "${workspaceRoot}/src/ApplePayJS/bin/Debug/net5.0/JustEat.ApplePayJS.dll",
       "args": [],
       "cwd": "${workspaceRoot}/src/ApplePayJS",
       "stopAtEntry": false,
diff --git a/Directory.Build.props b/Directory.Build.props
index 338eee34..f983eb5e 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -14,7 +14,7 @@
     <RepositoryType>git</RepositoryType>
     <RepositoryUrl>$(PackageProjectUrl).git</RepositoryUrl>
     <TypeScriptToolsVersion>latest</TypeScriptToolsVersion>
-    <VersionPrefix>3.1.0</VersionPrefix>
+    <VersionPrefix>5.0.0</VersionPrefix>
     <VersionSuffix></VersionSuffix>
   </PropertyGroup>
 </Project>
diff --git a/README.md b/README.md
index 7b5f13b3..bc8ab040 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 [![Build status](https://github.com/justeat/ApplePayJSSample/workflows/build/badge.svg?branch=master&event=push)](https://github.com/justeat/ApplePayJSSample/actions?query=workflow%3Abuild+branch%3Amaster+event%3Apush)
 
-This repository contains a sample implementation of [Apple Pay JS](https://developer.apple.com/reference/applepayjs/) using ASP.NET Core 3.1 written in C# and JavaScript.
+This repository contains a sample implementation of [Apple Pay JS](https://developer.apple.com/reference/applepayjs/) using ASP.NET 5.0 written in C# and JavaScript.
 
 ## Overview
 
@@ -21,7 +21,7 @@ The key components to look at for the implementation are:
 
 To setup the repository to run the sample, perform the steps below:
 
-  1. Install the latest [.NET Core 3.1 SDK](https://www.microsoft.com/net/download/core), Visual Studio 2019 or Visual Studio Code.
+  1. Install the latest [.NET 5.0 SDK](https://www.microsoft.com/net/download/core), Visual Studio 2019 or Visual Studio Code.
   1. Fork this repository.
   1. Clone the repository from your fork to your local machine: ```git clone https://github.com/{username}/ApplePayJSSample.git```
   1. Restore the Bower, npm and NuGet packages.
diff --git a/global.json b/global.json
index 94eb7bb6..fd0ce940 100644
--- a/global.json
+++ b/global.json
@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "3.1.402",
+    "version": "5.0.100",
     "allowPrerelease": false
   }
 }
diff --git a/src/ApplePayJS/ApplePayJS.csproj b/src/ApplePayJS/ApplePayJS.csproj
index 6765926b..47db48de 100644
--- a/src/ApplePayJS/ApplePayJS.csproj
+++ b/src/ApplePayJS/ApplePayJS.csproj
@@ -11,7 +11,7 @@
     <PackageTags>applepay</PackageTags>
     <PreserveCompilationContext>true</PreserveCompilationContext>
     <RootNamespace>JustEat.ApplePayJS</RootNamespace>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
     <TypeScriptToolsVersion>latest</TypeScriptToolsVersion>
     <UserSecretsId>JustEat.ApplePayJS</UserSecretsId>
   </PropertyGroup>
diff --git a/src/ApplePayJS/Clients/MerchantCertificate.cs b/src/ApplePayJS/Clients/MerchantCertificate.cs
index 4e4ac73a..3971b00a 100644
--- a/src/ApplePayJS/Clients/MerchantCertificate.cs
+++ b/src/ApplePayJS/Clients/MerchantCertificate.cs
@@ -63,7 +63,7 @@ private X509Certificate2 LoadCertificateFromDisk()
             try
             {
                 return new X509Certificate2(
-                    _options.MerchantCertificateFileName,
+                    _options.MerchantCertificateFileName ?? string.Empty,
                     _options.MerchantCertificatePassword);
             }
             catch (Exception ex)
@@ -84,7 +84,7 @@ private X509Certificate2 LoadCertificateFromStore()
 
             var certificates = store.Certificates.Find(
                 X509FindType.FindByThumbprint,
-                _options.MerchantCertificateThumbprint?.Trim(),
+                _options.MerchantCertificateThumbprint?.Trim() ?? string.Empty,
                 validOnly: false);
 
             if (certificates.Count < 1)
diff --git a/src/ApplePayJS/package-lock.json b/src/ApplePayJS/package-lock.json
index 2200b0e2..bb0d45ea 100644
--- a/src/ApplePayJS/package-lock.json
+++ b/src/ApplePayJS/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "justeatapplepayjs",
-  "version": "3.1.0",
+  "version": "5.0.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/src/ApplePayJS/package.json b/src/ApplePayJS/package.json
index 5570e403..26cea5d8 100644
--- a/src/ApplePayJS/package.json
+++ b/src/ApplePayJS/package.json
@@ -1,7 +1,7 @@
 {
   "name": "justeatapplepayjs",
   "private": true,
-  "version": "3.1.0",
+  "version": "5.0.0",
   "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 a9209bde..cb4b56f5 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>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
   <ItemGroup>
@@ -10,8 +10,8 @@
     <FrameworkReference Include="Microsoft.AspNetCore.App" />
     <PackageReference Include="JustEat.HttpClientInterception" Version="3.0.0" />
     <PackageReference Include="MartinCostello.Logging.XUnit" Version="0.1.0" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="3.1.8" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.6.1" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="5.0.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.1" />
     <PackageReference Include="Selenium.Support" Version="3.141.0" />
     <PackageReference Include="Selenium.WebDriver" Version="3.141.0" />
     <PackageReference Include="Selenium.WebDriver.ChromeDriver" Version="85.0.4183.8700" />
diff --git a/tests/ApplePayJS.Tests/TestFixture.cs b/tests/ApplePayJS.Tests/TestFixture.cs
index 19247fb2..1f877f00 100644
--- a/tests/ApplePayJS.Tests/TestFixture.cs
+++ b/tests/ApplePayJS.Tests/TestFixture.cs
@@ -127,7 +127,7 @@ private async Task CreateHttpServer()
             _host = builder.Build();
 
             // Force creation of the Kestrel server and start it
-            var hostedService = _host.Services.GetService<IHostedService>();
+            var hostedService = _host.Services.GetRequiredService<IHostedService>();
             await hostedService.StartAsync(default);
         }