diff --git a/serilog-sinks-file.sln b/serilog-sinks-file.sln
index 9c33a2b..8d76bf7 100644
--- a/serilog-sinks-file.sln
+++ b/serilog-sinks-file.sln
@@ -11,7 +11,6 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "assets", "assets", "{E9D1B5
 		appveyor.yml = appveyor.yml
 		Build.ps1 = Build.ps1
 		build.sh = build.sh
-		NuGet.Config = NuGet.Config
 		README.md = README.md
 		assets\Serilog.snk = assets\Serilog.snk
 	EndProjectSection
diff --git a/src/Serilog.Sinks.File/Serilog.Sinks.File.csproj b/src/Serilog.Sinks.File/Serilog.Sinks.File.csproj
index 6db7104..4048eba 100644
--- a/src/Serilog.Sinks.File/Serilog.Sinks.File.csproj
+++ b/src/Serilog.Sinks.File/Serilog.Sinks.File.csproj
@@ -4,7 +4,7 @@
     <Description>Write Serilog events to text files in plain or JSON format.</Description>
     <VersionPrefix>5.0.0</VersionPrefix>
     <Authors>Serilog Contributors</Authors>
-    <TargetFrameworks>net45;netstandard1.3;netstandard2.0;netstandard2.1</TargetFrameworks>
+    <TargetFrameworks>net45;netstandard1.3;netstandard2.0;netstandard2.1;net5.0</TargetFrameworks>
     <LangVersion>8.0</LangVersion>
     <Nullable>enable</Nullable>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
@@ -14,7 +14,7 @@
     <PackageTags>serilog;file</PackageTags>
     <PackageIcon>images\icon.png</PackageIcon>
     <PackageIconUrl>https://serilog.net/images/serilog-sink-nuget.png</PackageIconUrl>
-    <PackageProjectUrl>http://serilog.net</PackageProjectUrl>
+    <PackageProjectUrl>https://serilog.net</PackageProjectUrl>
     <PackageLicenseExpression>Apache-2.0</PackageLicenseExpression>
     <RepositoryUrl>https://github.com/serilog/serilog-sinks-file</RepositoryUrl>
     <RepositoryType>git</RepositoryType>
@@ -28,7 +28,8 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
-    <PackageReference Include="Serilog" Version="2.9.0" />
+    <PackageReference Include="Serilog" Version="2.10.0" />
+    <PackageReference Include="Nullable" Version="1.3.0" />
   </ItemGroup>
 
   <PropertyGroup Condition=" '$(TargetFramework)' == 'net45' ">
@@ -42,5 +43,5 @@
   <ItemGroup>
     <None Include="..\..\assets\serilog-sink-nuget.png" Pack="true" Visible="false" PackagePath="images\icon.png" />
   </ItemGroup>
-  
+
 </Project>
diff --git a/src/Serilog.Sinks.File/Support/NullableAttributes..cs b/src/Serilog.Sinks.File/Support/NullableAttributes..cs
deleted file mode 100644
index c7a2018..0000000
--- a/src/Serilog.Sinks.File/Support/NullableAttributes..cs
+++ /dev/null
@@ -1,140 +0,0 @@
-#pragma warning disable MA0048 // File name must match type name
-#define INTERNAL_NULLABLE_ATTRIBUTES
-#if NETSTANDARD1_0 || NETSTANDARD1_1 || NETSTANDARD1_2 || NETSTANDARD1_3 || NETSTANDARD1_4 || NETSTANDARD1_5 || NETSTANDARD1_6 || NETSTANDARD2_0 || NETCOREAPP1_0 || NETCOREAPP1_1 || NETCOREAPP2_0 || NETCOREAPP2_1 || NETCOREAPP2_2 || NET45 || NET451 || NET452 || NET46 || NET461 || NET462 || NET47 || NET471 || NET472 || NET48
-
-// https://github.com/dotnet/corefx/blob/48363ac826ccf66fbe31a5dcb1dc2aab9a7dd768/src/Common/src/CoreLib/System/Diagnostics/CodeAnalysis/NullableAttributes.cs
-
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-namespace System.Diagnostics.CodeAnalysis
-{
-    /// <summary>Specifies that null is allowed as an input even if the corresponding type disallows it.</summary>
-    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.Property, Inherited = false)]
-#if INTERNAL_NULLABLE_ATTRIBUTES
-    internal
-#else
-    public
-#endif
-        sealed class AllowNullAttribute : Attribute
-    { }
-
-    /// <summary>Specifies that null is disallowed as an input even if the corresponding type allows it.</summary>
-    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.Property, Inherited = false)]
-#if INTERNAL_NULLABLE_ATTRIBUTES
-    internal
-#else
-    public
-#endif
-        sealed class DisallowNullAttribute : Attribute
-    { }
-
-    /// <summary>Specifies that an output may be null even if the corresponding type disallows it.</summary>
-    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.ReturnValue, Inherited = false)]
-#if INTERNAL_NULLABLE_ATTRIBUTES
-    internal
-#else
-    public
-#endif
-        sealed class MaybeNullAttribute : Attribute
-    { }
-
-    /// <summary>Specifies that an output will not be null even if the corresponding type allows it.</summary>
-    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.ReturnValue, Inherited = false)]
-#if INTERNAL_NULLABLE_ATTRIBUTES
-    internal
-#else
-    public
-#endif
-        sealed class NotNullAttribute : Attribute
-    { }
-
-    /// <summary>Specifies that when a method returns <see cref="ReturnValue"/>, the parameter may be null even if the corresponding type disallows it.</summary>
-    [AttributeUsage(AttributeTargets.Parameter, Inherited = false)]
-#if INTERNAL_NULLABLE_ATTRIBUTES
-    internal
-#else
-    public
-#endif
-        sealed class MaybeNullWhenAttribute : Attribute
-    {
-        /// <summary>Initializes the attribute with the specified return value condition.</summary>
-        /// <param name="returnValue">
-        /// The return value condition. If the method returns this value, the associated parameter may be null.
-        /// </param>
-        public MaybeNullWhenAttribute(bool returnValue) => ReturnValue = returnValue;
-
-        /// <summary>Gets the return value condition.</summary>
-        public bool ReturnValue { get; }
-    }
-
-    /// <summary>Specifies that when a method returns <see cref="ReturnValue"/>, the parameter will not be null even if the corresponding type allows it.</summary>
-    [AttributeUsage(AttributeTargets.Parameter, Inherited = false)]
-#if INTERNAL_NULLABLE_ATTRIBUTES
-    internal
-#else
-    public
-#endif
-        sealed class NotNullWhenAttribute : Attribute
-    {
-        /// <summary>Initializes the attribute with the specified return value condition.</summary>
-        /// <param name="returnValue">
-        /// The return value condition. If the method returns this value, the associated parameter will not be null.
-        /// </param>
-        public NotNullWhenAttribute(bool returnValue) => ReturnValue = returnValue;
-
-        /// <summary>Gets the return value condition.</summary>
-        public bool ReturnValue { get; }
-    }
-
-    /// <summary>Specifies that the output will be non-null if the named parameter is non-null.</summary>
-    [AttributeUsage(AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.ReturnValue, AllowMultiple = true, Inherited = false)]
-#if INTERNAL_NULLABLE_ATTRIBUTES
-    internal
-#else
-    public
-#endif
-        sealed class NotNullIfNotNullAttribute : Attribute
-    {
-        /// <summary>Initializes the attribute with the associated parameter name.</summary>
-        /// <param name="parameterName">
-        /// The associated parameter name.  The output will be non-null if the argument to the parameter specified is non-null.
-        /// </param>
-        public NotNullIfNotNullAttribute(string parameterName) => ParameterName = parameterName;
-
-        /// <summary>Gets the associated parameter name.</summary>
-        public string ParameterName { get; }
-    }
-
-    /// <summary>Applied to a method that will never return under any circumstance.</summary>
-    [AttributeUsage(AttributeTargets.Method, Inherited = false)]
-#if INTERNAL_NULLABLE_ATTRIBUTES
-    internal
-#else
-    public
-#endif
-        sealed class DoesNotReturnAttribute : Attribute
-    { }
-
-    /// <summary>Specifies that the method will not return if the associated Boolean parameter is passed the specified value.</summary>
-    [AttributeUsage(AttributeTargets.Parameter, Inherited = false)]
-#if INTERNAL_NULLABLE_ATTRIBUTES
-    internal
-#else
-    public
-#endif
-        sealed class DoesNotReturnIfAttribute : Attribute
-    {
-        /// <summary>Initializes the attribute with the specified parameter value.</summary>
-        /// <param name="parameterValue">
-        /// The condition parameter value. Code after the method will be considered unreachable by diagnostics if the argument to
-        /// the associated parameter matches this value.
-        /// </param>
-        public DoesNotReturnIfAttribute(bool parameterValue) => ParameterValue = parameterValue;
-
-        /// <summary>Gets the condition parameter value.</summary>
-        public bool ParameterValue { get; }
-    }
-}
-#endif