diff --git a/NAPS2.App.Tests/AppTestData.cs b/NAPS2.App.Tests/AppTestData.cs
index 1a773f4302..ac87ff51a6 100644
--- a/NAPS2.App.Tests/AppTestData.cs
+++ b/NAPS2.App.Tests/AppTestData.cs
@@ -7,6 +7,7 @@ public class AppTestData : IEnumerable<object[]>
 {
     public IEnumerator<object[]> GetEnumerator()
     {
+#if NET6_0_OR_GREATER
         if (OperatingSystem.IsWindows())
         {
             yield return new object[] { new WinNet462AppTestTarget() };
@@ -19,6 +20,9 @@ public IEnumerator<object[]> GetEnumerator()
         {
             yield return new object[] { new LinuxAppTestTarget() };
         }
+#else
+        yield return new object[] { new WinNet462AppTestTarget() };
+#endif
     }
 
     IEnumerator IEnumerable.GetEnumerator()
diff --git a/NAPS2.App.Tests/Appium/AppiumTestData.cs b/NAPS2.App.Tests/Appium/AppiumTestData.cs
index ca039d1c3a..ddde7bb1cc 100644
--- a/NAPS2.App.Tests/Appium/AppiumTestData.cs
+++ b/NAPS2.App.Tests/Appium/AppiumTestData.cs
@@ -7,6 +7,7 @@ public class AppiumTestData : IEnumerable<object[]>
 {
     public IEnumerator<object[]> GetEnumerator()
     {
+#if NET6_0_OR_GREATER
         if (OperatingSystem.IsWindows())
         {
             yield return new object[] { new WinNet462AppTestTarget() };
@@ -19,6 +20,9 @@ public IEnumerator<object[]> GetEnumerator()
         {
             // No Appium impl yet
         }
+#else
+        yield return new object[] { new WinNet462AppTestTarget() };
+#endif
     }
 
     IEnumerator IEnumerable.GetEnumerator()
diff --git a/NAPS2.App.Tests/ConsoleAppTests.cs b/NAPS2.App.Tests/ConsoleAppTests.cs
index 7ca86ebddc..7b30d89323 100644
--- a/NAPS2.App.Tests/ConsoleAppTests.cs
+++ b/NAPS2.App.Tests/ConsoleAppTests.cs
@@ -45,7 +45,7 @@ public void NonZeroExitCodeForError(IAppTestTarget target)
         {
             Assert.True(process.WaitForExit(EXIT_TIMEOUT));
             var stdout = process.StandardOutput.ReadToEnd();
-            if (OperatingSystem.IsWindows())
+            if (target.IsWindows)
             {
                 // TODO: Figure out why ExitCode always appears as 0 on Mac/Linux
                 Assert.NotEqual(0, process.ExitCode);
diff --git a/NAPS2.App.Tests/GuiAppTests.cs b/NAPS2.App.Tests/GuiAppTests.cs
index 42b4baf1e4..34d37a36d5 100644
--- a/NAPS2.App.Tests/GuiAppTests.cs
+++ b/NAPS2.App.Tests/GuiAppTests.cs
@@ -14,7 +14,7 @@ public void CreatesWindow(IAppTestTarget target)
         var process = AppTestHelper.StartGuiProcess(target.Gui, FolderPath);
         try
         {
-            if (OperatingSystem.IsWindows())
+            if (target.IsWindows)
             {
                 AppTestHelper.WaitForVisibleWindow(process);
                 Assert.Equal("NAPS2 - Not Another PDF Scanner", process.MainWindowTitle);
diff --git a/NAPS2.App.Tests/IsExternalInit.cs b/NAPS2.App.Tests/IsExternalInit.cs
new file mode 100644
index 0000000000..0993ddec14
--- /dev/null
+++ b/NAPS2.App.Tests/IsExternalInit.cs
@@ -0,0 +1,5 @@
+// https://sergiopedri.medium.com/enabling-and-using-c-9-features-on-older-and-unsupported-runtimes-ce384d8debb
+// ReSharper disable once CheckNamespace
+namespace System.Runtime.CompilerServices;
+
+internal static class IsExternalInit {}
\ No newline at end of file
diff --git a/NAPS2.App.Tests/NAPS2.App.Tests.csproj b/NAPS2.App.Tests/NAPS2.App.Tests.csproj
index 87c9e8765d..a595446ffd 100644
--- a/NAPS2.App.Tests/NAPS2.App.Tests.csproj
+++ b/NAPS2.App.Tests/NAPS2.App.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('Windows'))">net8-windows</TargetFrameworks>
+        <TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('Windows'))">net462</TargetFrameworks>
         <TargetFrameworks Condition="!$([MSBuild]::IsOSPlatform('Windows'))">net8</TargetFrameworks>
         <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
         <ResolveAssemblyWarnOrErrorOnTargetArchitectureMismatch>None</ResolveAssemblyWarnOrErrorOnTargetArchitectureMismatch>
diff --git a/NAPS2.App.Tests/Targets/IAppTestTarget.cs b/NAPS2.App.Tests/Targets/IAppTestTarget.cs
index 454095706c..4d5243d3b0 100644
--- a/NAPS2.App.Tests/Targets/IAppTestTarget.cs
+++ b/NAPS2.App.Tests/Targets/IAppTestTarget.cs
@@ -5,4 +5,5 @@ public interface IAppTestTarget
     AppTestExe Console { get; }
     AppTestExe Gui { get; }
     AppTestExe Worker { get; }
+    bool IsWindows { get; }
 }
\ No newline at end of file
diff --git a/NAPS2.App.Tests/Targets/LinuxAppTestTarget.cs b/NAPS2.App.Tests/Targets/LinuxAppTestTarget.cs
index 0680ad6481..ef4ea90fc1 100644
--- a/NAPS2.App.Tests/Targets/LinuxAppTestTarget.cs
+++ b/NAPS2.App.Tests/Targets/LinuxAppTestTarget.cs
@@ -7,6 +7,7 @@ public class LinuxAppTestTarget : IAppTestTarget
     public AppTestExe Console => GetAppTestExe("console");
     public AppTestExe Gui => GetAppTestExe(null);
     public AppTestExe Worker => GetAppTestExe("worker");
+    public bool IsWindows => false;
 
     private AppTestExe GetAppTestExe(string argPrefix)
     {
diff --git a/NAPS2.App.Tests/Targets/MacAppTestTarget.cs b/NAPS2.App.Tests/Targets/MacAppTestTarget.cs
index b8476d9e98..8905217991 100644
--- a/NAPS2.App.Tests/Targets/MacAppTestTarget.cs
+++ b/NAPS2.App.Tests/Targets/MacAppTestTarget.cs
@@ -5,6 +5,7 @@ public class MacAppTestTarget : IAppTestTarget
     public AppTestExe Console => GetAppTestExe("console");
     public AppTestExe Gui => GetAppTestExe(null);
     public AppTestExe Worker => GetAppTestExe("worker");
+    public bool IsWindows => false;
 
     private AppTestExe GetAppTestExe(string argPrefix)
     {
diff --git a/NAPS2.App.Tests/Targets/WinNet462AppTestTarget.cs b/NAPS2.App.Tests/Targets/WinNet462AppTestTarget.cs
index 7b5f24ccaf..73d8f4973e 100644
--- a/NAPS2.App.Tests/Targets/WinNet462AppTestTarget.cs
+++ b/NAPS2.App.Tests/Targets/WinNet462AppTestTarget.cs
@@ -5,6 +5,7 @@ public class WinNet462AppTestTarget : IAppTestTarget
     public AppTestExe Console => GetAppTestExe("NAPS2.App.Console", "NAPS2.Console.exe", null);
     public AppTestExe Gui => GetAppTestExe("NAPS2.App.WinForms", "NAPS2.exe", null);
     public AppTestExe Worker => GetAppTestExe("NAPS2.App.Worker", "NAPS2.Worker.exe", "lib");
+    public bool IsWindows => true;
 
     private AppTestExe GetAppTestExe(string project, string exeName, string testRootSubPath)
     {
diff --git a/NAPS2.App.Tests/Verification/InstallDirTestData.cs b/NAPS2.App.Tests/Verification/InstallDirTestData.cs
index acf8cc2e04..e2e9f5b68b 100644
--- a/NAPS2.App.Tests/Verification/InstallDirTestData.cs
+++ b/NAPS2.App.Tests/Verification/InstallDirTestData.cs
@@ -6,7 +6,12 @@ public class InstallDirTestData : IEnumerable<object[]>
 {
     public IEnumerator<object[]> GetEnumerator()
     {
-        if (OperatingSystem.IsWindows() && !string.IsNullOrEmpty(Environment.GetEnvironmentVariable("NAPS2_TEST_VERIFY")))
+        if (string.IsNullOrEmpty(Environment.GetEnvironmentVariable("NAPS2_TEST_VERIFY")))
+        {
+            yield break;
+        }
+#if NET6_0_OR_GREATER
+        if (OperatingSystem.IsWindows())
         {
             yield return new object[] { Environment.GetEnvironmentVariable("NAPS2_TEST_ROOT") };
         }
@@ -18,6 +23,9 @@ public IEnumerator<object[]> GetEnumerator()
         {
             // No tests yet
         }
+#else
+        yield return new object[] { Environment.GetEnvironmentVariable("NAPS2_TEST_ROOT") };
+#endif
     }
 
     IEnumerator IEnumerable.GetEnumerator()
diff --git a/NAPS2.App.Tests/Verification/VerifyFactAttribute.cs b/NAPS2.App.Tests/Verification/VerifyFactAttribute.cs
index 9715d8e50f..f2b35901a3 100644
--- a/NAPS2.App.Tests/Verification/VerifyFactAttribute.cs
+++ b/NAPS2.App.Tests/Verification/VerifyFactAttribute.cs
@@ -40,10 +40,12 @@ public bool WindowsAppium
         get => _windowsAppium;
         set
         {
+#if NET6_0_OR_GREATER
             if (value && Skip == null && !OperatingSystem.IsWindows())
             {
                 Skip = "Appium tests are only supported on Windows right now.";
             }
+#endif
             _windowsAppium = value;
         }
     }
diff --git a/NAPS2.Sdk.ScannerTests/NAPS2.Sdk.ScannerTests.csproj b/NAPS2.Sdk.ScannerTests/NAPS2.Sdk.ScannerTests.csproj
index b142994819..ed8a88d551 100644
--- a/NAPS2.Sdk.ScannerTests/NAPS2.Sdk.ScannerTests.csproj
+++ b/NAPS2.Sdk.ScannerTests/NAPS2.Sdk.ScannerTests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('Windows'))">net8-windows;net462</TargetFrameworks>
+        <TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('Windows'))">net462</TargetFrameworks>
         <TargetFrameworks Condition="!$([MSBuild]::IsOSPlatform('Windows'))">net8</TargetFrameworks>
         <RootNamespace>NAPS2.Sdk.ScannerTests</RootNamespace>
     </PropertyGroup>