diff --git a/src/activities/Elsa.Activities.Http/Elsa.Activities.Http.csproj b/src/activities/Elsa.Activities.Http/Elsa.Activities.Http.csproj
index 0a56607ac..dec7eb162 100644
--- a/src/activities/Elsa.Activities.Http/Elsa.Activities.Http.csproj
+++ b/src/activities/Elsa.Activities.Http/Elsa.Activities.Http.csproj
@@ -4,7 +4,7 @@
     <Import Project="..\..\..\configureawait.props" />
     
     <PropertyGroup>
-        <TargetFrameworks>netcoreapp3.1;net5.0</TargetFrameworks>        
+        <TargetFramework>netstandard2.1</TargetFramework>        
         <Description>
             Elsa is a set of workflow libraries and tools that enable lean and mean workflowing capabilities in any .NET Core application.
             This package provides the following Console activities:
diff --git a/src/activities/Elsa.Activities.Telnyx/Activities/BridgeCalls.cs b/src/activities/Elsa.Activities.Telnyx/Activities/BridgeCalls.cs
index 80ecd25f8..efbddc4eb 100644
--- a/src/activities/Elsa.Activities.Telnyx/Activities/BridgeCalls.cs
+++ b/src/activities/Elsa.Activities.Telnyx/Activities/BridgeCalls.cs
@@ -141,7 +141,7 @@ namespace Elsa.Activities.Telnyx.Activities
                 return input.CallControlId;
 
             var inboundCallActivityId = context.WorkflowExecutionContext.GetInboundConnections(Id).Where(x => x.Source.Activity.Type == nameof(Dial)).Select(x => x.Source.Activity.Id).FirstOrDefault();
-            var inboundCallActivityResponse = inboundCallActivityId != null ? await context.WorkflowExecutionContext.GetActivityPropertyAsync<Dial, DialResponse>(inboundCallActivityId, x => x.DialResponse) : default;
+            var inboundCallActivityResponse = inboundCallActivityId != null ? await context.WorkflowExecutionContext.GetActivityPropertyAsync<Dial, DialResponse>(inboundCallActivityId, x => x.DialResponse!) : default;
             return inboundCallActivityResponse != null ? inboundCallActivityResponse.CallControlId : null;
         }
     }
diff --git a/src/activities/Elsa.Activities.Telnyx/Elsa.Activities.Telnyx.csproj b/src/activities/Elsa.Activities.Telnyx/Elsa.Activities.Telnyx.csproj
index 4ca4ff3e1..20d7274ba 100644
--- a/src/activities/Elsa.Activities.Telnyx/Elsa.Activities.Telnyx.csproj
+++ b/src/activities/Elsa.Activities.Telnyx/Elsa.Activities.Telnyx.csproj
@@ -2,7 +2,7 @@
 
     <Import Project="..\..\..\common.props" />
     <Import Project="..\..\..\configureawait.props" />
-    
+
     <PropertyGroup>
         <TargetFramework>net5.0</TargetFramework>
         <Description>
@@ -15,22 +15,19 @@
     <ItemGroup>
         <FrameworkReference Include="Microsoft.AspNetCore.App" />
     </ItemGroup>
-    
+
     <ItemGroup>
-      <ProjectReference Include="..\..\core\Elsa.Core\Elsa.Core.csproj" />
-      <ProjectReference Include="..\..\scripting\Elsa.Scripting.JavaScript\Elsa.Scripting.JavaScript.csproj" />
-      <ProjectReference Include="..\..\scripting\Elsa.Scripting.Liquid\Elsa.Scripting.Liquid.csproj" />
-      <ProjectReference Include="..\Elsa.Activities.Temporal.Common\Elsa.Activities.Temporal.Common.csproj" />
+        <ProjectReference Include="..\..\core\Elsa.Core\Elsa.Core.csproj" />
+        <ProjectReference Include="..\..\scripting\Elsa.Scripting.JavaScript\Elsa.Scripting.JavaScript.csproj" />
+        <ProjectReference Include="..\..\scripting\Elsa.Scripting.Liquid\Elsa.Scripting.Liquid.csproj" />
+        <ProjectReference Include="..\Elsa.Activities.Temporal.Common\Elsa.Activities.Temporal.Common.csproj" />
     </ItemGroup>
-    
+
     <ItemGroup>
-      <PackageReference Include="Refit" Version="6.0.38" />
-      <PackageReference Include="Refit.HttpClientFactory" Version="6.0.38" />
-      <PackageReference Include="Refit.Newtonsoft.Json" Version="6.0.38" />
-    </ItemGroup>
-    
-    <ItemGroup>
-      <Folder Include="Providers" />
+        <PackageReference Include="Refit" Version="6.0.38" />
+        <PackageReference Include="Refit.HttpClientFactory" Version="6.0.38" />
+        <PackageReference Include="Refit.Newtonsoft.Json" Version="6.0.38" />
+        <PackageReference Include="System.Text.Encodings.Web" Version="5.0.1" />
     </ItemGroup>
 
 </Project>
diff --git a/src/activities/Elsa.Activities.Telnyx/Models/ClientStatePayload.cs b/src/activities/Elsa.Activities.Telnyx/Models/ClientStatePayload.cs
index 78e5285aa..c18cea46a 100644
--- a/src/activities/Elsa.Activities.Telnyx/Models/ClientStatePayload.cs
+++ b/src/activities/Elsa.Activities.Telnyx/Models/ClientStatePayload.cs
@@ -10,7 +10,7 @@ namespace Elsa.Activities.Telnyx.Models
         {
             var bytes = Convert.FromBase64String(base64);
             var json = Encoding.UTF8.GetString(bytes);
-            return JsonConvert.DeserializeObject<ClientStatePayload>(json);
+            return JsonConvert.DeserializeObject<ClientStatePayload>(json)!;
         }
         
         public string ToBase64()
diff --git a/src/core/Elsa.Abstractions/Services/Models/ActivityExecutionContext.cs b/src/core/Elsa.Abstractions/Services/Models/ActivityExecutionContext.cs
index b038a7825..c66dbeea3 100644
--- a/src/core/Elsa.Abstractions/Services/Models/ActivityExecutionContext.cs
+++ b/src/core/Elsa.Abstractions/Services/Models/ActivityExecutionContext.cs
@@ -46,7 +46,7 @@ namespace Elsa.Services.Models
         public bool Resuming { get; }
         public bool IsFirstPass => WorkflowExecutionContext.IsFirstPass;
 
-        public string? CorrelationId
+        public string CorrelationId
         {
             get => WorkflowExecutionContext.CorrelationId;
             set => WorkflowExecutionContext.CorrelationId = value;