diff --git a/Apex.Serialization/Apex.Serialization.csproj b/Apex.Serialization/Apex.Serialization.csproj
index a4bf2cb..afa75b8 100644
--- a/Apex.Serialization/Apex.Serialization.csproj
+++ b/Apex.Serialization/Apex.Serialization.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks>net5</TargetFrameworks>
     <LangVersion>8.0</LangVersion>
     <Version>2.0.1</Version>
     <Authors>Dominic Bolin</Authors>
diff --git a/Apex.Serialization/Binary.Internal.cs b/Apex.Serialization/Binary.Internal.cs
index 65e46b1..b273fad 100644
--- a/Apex.Serialization/Binary.Internal.cs
+++ b/Apex.Serialization/Binary.Internal.cs
@@ -456,7 +456,7 @@ private static Func<object, object> CreateCloneFunc()
         {
             var p = Expression.Parameter(typeof(object));
             return Expression.Lambda<Func<object, object>>(
-                Expression.Call(p, typeof(object).GetMethod("MemberwiseClone", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.DeclaredOnly))
+                Expression.Call(p, typeof(object).GetMethod("MemberwiseClone", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.DeclaredOnly)!)
                 , p
             ).Compile();
         }
@@ -468,7 +468,7 @@ private static Action<Delegate, object> CreateSetTargetAction()
             return Expression.Lambda<Action<Delegate, object>>(
                 Expression.Assign(
                     Expression.MakeMemberAccess(p,
-                        typeof(Delegate).GetField("_target", BindingFlags.Instance | BindingFlags.DeclaredOnly | BindingFlags.NonPublic)), t)
+                        typeof(Delegate).GetField("_target", BindingFlags.Instance | BindingFlags.DeclaredOnly | BindingFlags.NonPublic)!), t)
                 , p, t
             ).Compile();
         }
diff --git a/Apex.Serialization/Internal/DynamicCode.cs b/Apex.Serialization/Internal/DynamicCode.cs
index 93c767f..a69632e 100644
--- a/Apex.Serialization/Internal/DynamicCode.cs
+++ b/Apex.Serialization/Internal/DynamicCode.cs
@@ -650,7 +650,7 @@ private static List<Expression> GetReadStatementsForType(Type type, ImmutableSet
                 readStatements.Add(
                     Expression.IfThen(
                             Expression.Equal(Expression.Call(stream, BinaryStreamMethods<TStream>.GenericMethods<byte>.ReadValueMethodInfo), Expression.Constant((byte)0)),
-                            Expression.Goto(skipReadLabel)
+                            Expression.Goto(skipReadLabel!)
                         )
                     );
 
@@ -672,7 +672,7 @@ private static List<Expression> GetReadStatementsForType(Type type, ImmutableSet
                                                 SavedReferencesListIndexer, Expression.Decrement(refIndex)),
                                             type)
                                         ),
-                                        Expression.Goto(skipReadLabel)
+                                        Expression.Goto(skipReadLabel!)
                                     )
                                 )
                             )
diff --git a/Apex.Serialization/Internal/Reflection/FieldInfoModifier.cs b/Apex.Serialization/Internal/Reflection/FieldInfoModifier.cs
index 282b6e8..4256ab8 100644
--- a/Apex.Serialization/Internal/Reflection/FieldInfoModifier.cs
+++ b/Apex.Serialization/Internal/Reflection/FieldInfoModifier.cs
@@ -35,7 +35,7 @@ static FieldInfoModifier()
             if (fieldInfo_m_Attributes != null)
             {
                 var fieldInfoParam = Expression.Parameter(typeof(FieldInfo));
-                var castedType = Expression.Convert(fieldInfoParam, type);
+                var castedType = Expression.Convert(fieldInfoParam, type!);
                 var returnLabel = Expression.Label();
                 SetFieldInfoNotReadonly = (Action<FieldInfo>)Expression.Lambda(
                     Expression.Block(
diff --git a/Apex.Serialization/Internal/Reflection/TypeFields.cs b/Apex.Serialization/Internal/Reflection/TypeFields.cs
index f2bca4d..a58b074 100644
--- a/Apex.Serialization/Internal/Reflection/TypeFields.cs
+++ b/Apex.Serialization/Internal/Reflection/TypeFields.cs
@@ -21,7 +21,7 @@ static TypeFields()
             var intPtrParam = Expression.Parameter(typeof(IntPtr));
             var objectParam = Expression.Parameter(typeof(object));
 
-            var logicallyNullMethod = typeof(MulticastDelegate).GetMethod("InvocationListLogicallyNull", BindingFlags.Instance | BindingFlags.NonPublic);
+            var logicallyNullMethod = typeof(MulticastDelegate).GetMethod("InvocationListLogicallyNull", BindingFlags.Instance | BindingFlags.NonPublic)!;
 
             getInvocationCount = Expression.Lambda<Func<MulticastDelegate, IntPtr>>(Expression.Field(delegateParam, "_invocationCount"), delegateParam).Compile();
             getInvocationList = Expression.Lambda<Func<MulticastDelegate, object>>(Expression.Field(delegateParam, "_invocationList"), delegateParam).Compile();
diff --git a/Apex.Serialization/Internal/VersionUniqueIdExpressionVisitor.cs b/Apex.Serialization/Internal/VersionUniqueIdExpressionVisitor.cs
index 99255fc..5929ee5 100644
--- a/Apex.Serialization/Internal/VersionUniqueIdExpressionVisitor.cs
+++ b/Apex.Serialization/Internal/VersionUniqueIdExpressionVisitor.cs
@@ -189,7 +189,7 @@ protected override Expression VisitLabel(LabelExpression node)
             return base.VisitLabel(node);
         }
 
-        protected override LabelTarget VisitLabelTarget(LabelTarget? node)
+        protected override LabelTarget? VisitLabelTarget(LabelTarget? node)
         {
             if (node != null)
             {
diff --git a/Benchmark/Benchmark.csproj b/Benchmark/Benchmark.csproj
index 825d4f3..efd98ad 100644
--- a/Benchmark/Benchmark.csproj
+++ b/Benchmark/Benchmark.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5</TargetFramework>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>Benchmark.snk</AssemblyOriginatorKeyFile>
     <LangVersion>8.0</LangVersion>
diff --git a/Benchmark/Program.cs b/Benchmark/Program.cs
index 41eadf0..717c6de 100644
--- a/Benchmark/Program.cs
+++ b/Benchmark/Program.cs
@@ -26,8 +26,7 @@ public Config()
             AddExporter(DefaultConfig.Instance.GetExporters().ToArray()); // manual config has no exporters by default
             AddColumnProvider(DefaultConfig.Instance.GetColumnProviders().ToArray()); // manual config has no columns by default
 
-            //AddJob(Job.Default.With(CsProjCoreToolchain.NetCoreApp30).WithGcServer(false));
-            AddJob(Job.Default.With(CsProjCoreToolchain.NetCoreApp31).WithGcServer(true));
+            AddJob(Job.Default.WithToolchain(CsProjCoreToolchain.NetCoreApp50).WithGcServer(true));
             //AddJob(Job.Clr.With(CsProjClassicNetToolchain.Net472));
             //AddJob(Job.CoreRT);
             //Add(HardwareCounter.BranchMispredictions, HardwareCounter.BranchInstructions);
diff --git a/DeserializeTest/DeserializeTest.csproj b/DeserializeTest/DeserializeTest.csproj
index 1cd5f43..3c1b2a4 100644
--- a/DeserializeTest/DeserializeTest.csproj
+++ b/DeserializeTest/DeserializeTest.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/DeserializeTest2/DeserializeTest2.csproj b/DeserializeTest2/DeserializeTest2.csproj
index 1cd5f43..3c1b2a4 100644
--- a/DeserializeTest2/DeserializeTest2.csproj
+++ b/DeserializeTest2/DeserializeTest2.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net5</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Tests/Apex.Serialization.Tests/Apex.Serialization.Tests.csproj b/Tests/Apex.Serialization.Tests/Apex.Serialization.Tests.csproj
index 6438fc1..82687e3 100644
--- a/Tests/Apex.Serialization.Tests/Apex.Serialization.Tests.csproj
+++ b/Tests/Apex.Serialization.Tests/Apex.Serialization.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks>net5</TargetFrameworks>
     <IsPackable>false</IsPackable>
     <LangVersion>8.0</LangVersion>
     <SignAssembly>true</SignAssembly>
@@ -12,10 +12,6 @@
     <NoWarn>CS8605;CS8602;CS0649;CS8002</NoWarn>
   </PropertyGroup>
 
-  <PropertyGroup Condition="'$(Configuration)|$(Framework)'=='netcoreapp3.1'">
-    <DefineConstants>NETCOREAPP</DefineConstants>
-  </PropertyGroup>
-  
   <ItemGroup>
     <PackageReference Include="coverlet.msbuild" Version="2.9.0">
       <PrivateAssets>all</PrivateAssets>