diff --git a/Build/Build.cs b/Build/Build.cs
index 12420110fd..e0994760f8 100644
--- a/Build/Build.cs
+++ b/Build/Build.cs
@@ -168,9 +168,6 @@ class Build : NukeBuild
.SetTargetDirectory(TestResultsDirectory / "reports")
.AddReports(TestResultsDirectory / "**/coverage.cobertura.xml")
.AddReportTypes("HtmlInline_AzurePipelines_Dark", "lcov")
- .SetClassFilters(
- "-System.Diagnostics.CodeAnalysis.StringSyntaxAttribute",
- "-System.Diagnostics.CodeAnalysis.DoesNotReturnAttribute")
.SetAssemblyFilters("+FluentAssertions"));
string link = TestResultsDirectory / "reports" / "index.html";
diff --git a/Src/FluentAssertions/DoesNotReturnAttribute.cs b/Src/FluentAssertions/DoesNotReturnAttribute.cs
deleted file mode 100644
index 9a5d558f29..0000000000
--- a/Src/FluentAssertions/DoesNotReturnAttribute.cs
+++ /dev/null
@@ -1,17 +0,0 @@
-// copied from https://source.dot.net/#System.Private.CoreLib/NullableAttributes.cs
-#if !(NETSTANDARD2_1_OR_GREATER || NETCOREAPP3_0_OR_GREATER)
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-namespace System.Diagnostics.CodeAnalysis;
-
-/// Applied to a method that will never return under any circumstance.
-[AttributeUsage(AttributeTargets.Method, Inherited = false)]
-#if SYSTEM_PRIVATE_CORELIB
-public
-#else
-internal
-#endif
- sealed class DoesNotReturnAttribute : Attribute
-{
-}
-#endif
diff --git a/Src/FluentAssertions/FluentAssertions.csproj b/Src/FluentAssertions/FluentAssertions.csproj
index f1afb9908f..abe53006ae 100644
--- a/Src/FluentAssertions/FluentAssertions.csproj
+++ b/Src/FluentAssertions/FluentAssertions.csproj
@@ -55,6 +55,7 @@
+
diff --git a/Src/FluentAssertions/StringSyntaxAttribute.cs b/Src/FluentAssertions/StringSyntaxAttribute.cs
deleted file mode 100644
index 8253978af5..0000000000
--- a/Src/FluentAssertions/StringSyntaxAttribute.cs
+++ /dev/null
@@ -1,50 +0,0 @@
-// copied from https://raw.githubusercontent.com/dotnet/runtime/main/src/libraries/System.Private.CoreLib/src/System/Diagnostics/CodeAnalysis/StringSyntaxAttribute.cs
-#if !NET7_0_OR_GREATER
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-#nullable enable
-
-namespace System.Diagnostics.CodeAnalysis;
-
-/// Specifies the syntax used in a string.
-[AttributeUsage(AttributeTargets.Parameter | AttributeTargets.Field | AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
-#if SYSTEM_PRIVATE_CORELIB
-public
-#else
-internal
-#endif
-sealed class StringSyntaxAttribute : Attribute
-{
- /// Initializes the with the identifier of the syntax used.
- /// The syntax identifier.
- public StringSyntaxAttribute(string syntax)
- {
- Syntax = syntax;
- Arguments = Array.Empty