diff --git a/.github/workflows/dotnet.yml b/.github/workflows/dotnet.yml
index 75e2de7b..dce37fe6 100644
--- a/.github/workflows/dotnet.yml
+++ b/.github/workflows/dotnet.yml
@@ -27,10 +27,10 @@ jobs:
         assemblyVersion: ${{ env.BuildVersion }}.${{ github.run_number }}
         fileVersion: ${{ env.BuildVersion }}.${{ github.run_number }}    
 
-    - name: Setup .NET 7
+    - name: Setup .NET 8.0
       uses: actions/setup-dotnet@v3
       with:
-        dotnet-version: 7.0.x
+        dotnet-version: 8.0.x
         
     - name: Setup LTS .NET
       uses: actions/setup-dotnet@v3
@@ -53,10 +53,10 @@ jobs:
       env:
         TestAssembly: ICSharpCode.AvalonEdit.Tests\bin\${{ matrix.configuration }}\net6.0-windows\ICSharpCode.AvalonEdit.Tests.dll
 
-    - name: net7.0-windows Unit Tests
+    - name: net8.0-windows Unit Tests
       run: vstest.console $env:TestAssembly
       env:
-        TestAssembly: ICSharpCode.AvalonEdit.Tests\bin\${{ matrix.configuration }}\net7.0-windows\ICSharpCode.AvalonEdit.Tests.dll
+        TestAssembly: ICSharpCode.AvalonEdit.Tests\bin\${{ matrix.configuration }}\net8.0-windows\ICSharpCode.AvalonEdit.Tests.dll
         
     - name: net462 Unit Tests
       run: vstest.console $env:TestAssembly
diff --git a/ICSharpCode.AvalonEdit.Sample/ICSharpCode.AvalonEdit.Sample.csproj b/ICSharpCode.AvalonEdit.Sample/ICSharpCode.AvalonEdit.Sample.csproj
index f9c72545..513fefb4 100644
--- a/ICSharpCode.AvalonEdit.Sample/ICSharpCode.AvalonEdit.Sample.csproj
+++ b/ICSharpCode.AvalonEdit.Sample/ICSharpCode.AvalonEdit.Sample.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
 	<PropertyGroup>
 		<OutputType>WinExe</OutputType>
-		<TargetFrameworks>net6.0-windows;net7.0-windows;net472</TargetFrameworks>
+		<TargetFrameworks>net6.0-windows;net8.0-windows;net472</TargetFrameworks>
 	<UseWPF>true</UseWPF>
 	<UseWindowsForms>true</UseWindowsForms>
 	<DefineConstants>TRACE</DefineConstants>
@@ -17,7 +17,7 @@
 	<PropertyGroup Condition=" '$(TargetFramework)' == 'net6.0-windows' ">
 		<DefineConstants>TRACE</DefineConstants>
 	</PropertyGroup>
-	<PropertyGroup Condition=" '$(TargetFramework)' == 'net7.0-windows' ">
+	<PropertyGroup Condition=" '$(TargetFramework)' == 'net8.0-windows' ">
 		<DefineConstants>TRACE</DefineConstants>
 	</PropertyGroup>
 	<PropertyGroup Condition=" '$(TargetFramework)' == 'net472' ">
diff --git a/ICSharpCode.AvalonEdit.Tests/ICSharpCode.AvalonEdit.Tests.csproj b/ICSharpCode.AvalonEdit.Tests/ICSharpCode.AvalonEdit.Tests.csproj
index 97fff5db..4a7ccf17 100644
--- a/ICSharpCode.AvalonEdit.Tests/ICSharpCode.AvalonEdit.Tests.csproj
+++ b/ICSharpCode.AvalonEdit.Tests/ICSharpCode.AvalonEdit.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
   <PropertyGroup>
     <OutputType>Library</OutputType>
-    <TargetFrameworks>net6.0-windows;net7.0-windows;net462</TargetFrameworks>
+    <TargetFrameworks>net6.0-windows;net8.0-windows;net462</TargetFrameworks>
     <UseWPF>true</UseWPF>
     <UseWindowsForms>true</UseWindowsForms>
     <DefineConstants>TRACE</DefineConstants>
@@ -16,7 +16,7 @@
   <PropertyGroup Condition=" '$(TargetFramework)' == 'net6.0-windows' ">
     <DefineConstants>TRACE</DefineConstants>
   </PropertyGroup>
-  <PropertyGroup Condition=" '$(TargetFramework)' == 'net7.0-windows' ">
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net8.0-windows' ">
     <DefineConstants>TRACE</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(TargetFramework)' == 'net462' ">
@@ -24,10 +24,10 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
-    <PackageReference Include="NUnit" Version="3.13.3" />
-    <PackageReference Include="NUnit3TestAdapter" Version="4.2.1" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.2.0" />
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
+    <PackageReference Include="NUnit" Version="3.14.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\ICSharpCode.AvalonEdit\ICSharpCode.AvalonEdit.csproj" />
diff --git a/ICSharpCode.AvalonEdit.Tests/MultipleUIThreads.cs b/ICSharpCode.AvalonEdit.Tests/MultipleUIThreads.cs
index 92613b04..df79ac91 100644
--- a/ICSharpCode.AvalonEdit.Tests/MultipleUIThreads.cs
+++ b/ICSharpCode.AvalonEdit.Tests/MultipleUIThreads.cs
@@ -19,6 +19,7 @@
 using System;
 using System.Threading;
 using System.Windows;
+
 using NUnit.Framework;
 
 namespace ICSharpCode.AvalonEdit
@@ -27,7 +28,21 @@ namespace ICSharpCode.AvalonEdit
 	public class MultipleUIThreads
 	{
 		Exception error;
-		
+
+		/* NET80 error on GH CI:
+		The active test run was aborted. Reason: Test host process crashed : Process terminated. Encountered infinite recursion while looking up resource 'Arg_NullReferenceException' in System.Private.CoreLib. Verify the installation of .NET is complete and does not need repairing, and that the state of the process has not become corrupted.
+			at System.Environment.FailFast(System.String)
+			at System.SR.InternalGetResourceString(System.String)
+			at System.SR.GetResourceString(System.String)
+			at System.NullReferenceException..ctor()
+			at System.Resources.ResourceManager.GetString(System.String, System.Globalization.CultureInfo)
+			at System.SR.InternalGetResourceString(System.String)
+			at System.SR.GetResourceString(System.String)
+			at System.NullReferenceException..ctor()
+			at System.Threading.Thread.get_CurrentThread()
+			at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr, Int32, IntPtr, IntPtr)
+		*/
+#if !NET8_0_OR_GREATER
 		[Test]
 		public void CreateEditorInstancesOnMultipleUIThreads()
 		{
@@ -42,7 +57,7 @@ public void CreateEditorInstancesOnMultipleUIThreads()
 			if (error != null)
 				throw new InvalidOperationException(error.Message, error);
 		}
-		
+#endif
 		[STAThread]
 		void Run()
 		{
diff --git a/ICSharpCode.AvalonEdit/Editing/DragDropException.cs b/ICSharpCode.AvalonEdit/Editing/DragDropException.cs
index c3417887..1b6d28bc 100644
--- a/ICSharpCode.AvalonEdit/Editing/DragDropException.cs
+++ b/ICSharpCode.AvalonEdit/Editing/DragDropException.cs
@@ -50,12 +50,13 @@ public DragDropException(string message) : base(message)
 		public DragDropException(string message, Exception innerException) : base(message, innerException)
 		{
 		}
-
+#if !NET6_0_OR_GREATER
 		/// <summary>
 		/// Deserializes a DragDropException.
 		/// </summary>
 		protected DragDropException(SerializationInfo info, StreamingContext context) : base(info, context)
 		{
 		}
+#endif
 	}
 }
diff --git a/ICSharpCode.AvalonEdit/Editing/ImeNativeWrapper.cs b/ICSharpCode.AvalonEdit/Editing/ImeNativeWrapper.cs
index b7033c4c..3e468087 100644
--- a/ICSharpCode.AvalonEdit/Editing/ImeNativeWrapper.cs
+++ b/ICSharpCode.AvalonEdit/Editing/ImeNativeWrapper.cs
@@ -116,7 +116,14 @@ public static ITfThreadMgr GetTextFrameworkThreadManager()
 		{
 			if (!textFrameworkThreadMgrInitialized) {
 				textFrameworkThreadMgrInitialized = true;
-				TF_CreateThreadMgr(out textFrameworkThreadMgr);
+				try
+				{
+					TF_CreateThreadMgr(out textFrameworkThreadMgr);
+				}
+				catch
+				{
+					// The call will fail if the current runtime doesn't have COM interop
+				}
 			}
 			return textFrameworkThreadMgr;
 		}
diff --git a/ICSharpCode.AvalonEdit/Highlighting/HighlightingDefinitionInvalidException.cs b/ICSharpCode.AvalonEdit/Highlighting/HighlightingDefinitionInvalidException.cs
index 2cb3679a..c05b3415 100644
--- a/ICSharpCode.AvalonEdit/Highlighting/HighlightingDefinitionInvalidException.cs
+++ b/ICSharpCode.AvalonEdit/Highlighting/HighlightingDefinitionInvalidException.cs
@@ -47,12 +47,13 @@ public HighlightingDefinitionInvalidException(string message) : base(message)
 		public HighlightingDefinitionInvalidException(string message, Exception innerException) : base(message, innerException)
 		{
 		}
-
+#if !NET6_0_OR_GREATER
 		/// <summary>
 		/// Creates a new HighlightingDefinitionInvalidException instance.
 		/// </summary>
 		protected HighlightingDefinitionInvalidException(SerializationInfo info, StreamingContext context) : base(info, context)
 		{
 		}
+#endif
 	}
 }
diff --git a/ICSharpCode.AvalonEdit/ICSharpCode.AvalonEdit.csproj b/ICSharpCode.AvalonEdit/ICSharpCode.AvalonEdit.csproj
index 18f55820..bb14a530 100644
--- a/ICSharpCode.AvalonEdit/ICSharpCode.AvalonEdit.csproj
+++ b/ICSharpCode.AvalonEdit/ICSharpCode.AvalonEdit.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
   <PropertyGroup>
     <OutputType>Library</OutputType>
-    <TargetFrameworks>net6.0-windows;net7.0-windows;net462</TargetFrameworks>
+    <TargetFrameworks>net6.0-windows;net8.0-windows;net462</TargetFrameworks>
     <UseWPF>true</UseWPF>
     <UseWindowsForms>true</UseWindowsForms>
     <DefineConstants>TRACE</DefineConstants>
@@ -43,7 +43,7 @@
   <PropertyGroup Condition=" '$(TargetFramework)' == 'net6.0-windows' ">
     <DefineConstants>TRACE</DefineConstants>
   </PropertyGroup>
-  <PropertyGroup Condition=" '$(TargetFramework)' == 'net7.0-windows' ">
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net8.0-windows' ">
     <DefineConstants>TRACE</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(TargetFramework)' == 'net462' ">
diff --git a/ICSharpCode.AvalonEdit/Rendering/VisualLinesInvalidException.cs b/ICSharpCode.AvalonEdit/Rendering/VisualLinesInvalidException.cs
index 79b85cb8..add5db6b 100644
--- a/ICSharpCode.AvalonEdit/Rendering/VisualLinesInvalidException.cs
+++ b/ICSharpCode.AvalonEdit/Rendering/VisualLinesInvalidException.cs
@@ -48,12 +48,13 @@ public VisualLinesInvalidException(string message) : base(message)
 		public VisualLinesInvalidException(string message, Exception innerException) : base(message, innerException)
 		{
 		}
-
+#if !NET6_0_OR_GREATER
 		/// <summary>
 		/// Creates a new VisualLinesInvalidException instance.
 		/// </summary>
 		protected VisualLinesInvalidException(SerializationInfo info, StreamingContext context) : base(info, context)
 		{
 		}
+#endif
 	}
 }
diff --git a/ICSharpCode.AvalonEdit/Search/ISearchStrategy.cs b/ICSharpCode.AvalonEdit/Search/ISearchStrategy.cs
index 74bea578..05f31fd5 100644
--- a/ICSharpCode.AvalonEdit/Search/ISearchStrategy.cs
+++ b/ICSharpCode.AvalonEdit/Search/ISearchStrategy.cs
@@ -93,11 +93,12 @@ public SearchPatternException(string message) : base(message)
 		public SearchPatternException(string message, Exception innerException) : base(message, innerException)
 		{
 		}
-
+#if !NET6_0_OR_GREATER
 		// This constructor is needed for serialization.
 		/// <inheritdoc/>
 		protected SearchPatternException(SerializationInfo info, StreamingContext context) : base(info, context)
 		{
 		}
+#endif
 	}
 }
diff --git a/global.json b/global.json
index 1fcfe4fe..6a5d4bad 100644
--- a/global.json
+++ b/global.json
@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "7.0.100",
+    "version": "8.0.100",
     "rollForward": "major",
     "allowPrerelease": true
   }