diff --git a/AIStudio.Wpf.DiagramDesigner/ViewModels/AdditionViewModel/ColorViewModel.cs b/AIStudio.Wpf.DiagramDesigner/ViewModels/AdditionViewModel/ColorViewModel.cs
index c788c53..f5ecd20 100644
--- a/AIStudio.Wpf.DiagramDesigner/ViewModels/AdditionViewModel/ColorViewModel.cs
+++ b/AIStudio.Wpf.DiagramDesigner/ViewModels/AdditionViewModel/ColorViewModel.cs
@@ -1,10 +1,6 @@
 using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.ComponentModel.DataAnnotations;
 using System.Linq;
-using System.Text;
-using System.Threading;
 using System.Windows;
 using System.Windows.Input;
 using System.Windows.Media;
diff --git a/AIStudio.Wpf.DiagramDesigner/ViewModels/DefaultViewModel/LogicalGateItemViewModelBase.cs b/AIStudio.Wpf.DiagramDesigner/ViewModels/DefaultViewModel/LogicalGateItemViewModelBase.cs
index 11fa1bf..d13f6ed 100644
--- a/AIStudio.Wpf.DiagramDesigner/ViewModels/DefaultViewModel/LogicalGateItemViewModelBase.cs
+++ b/AIStudio.Wpf.DiagramDesigner/ViewModels/DefaultViewModel/LogicalGateItemViewModelBase.cs
@@ -1,11 +1,6 @@
-using System;
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.ComponentModel.DataAnnotations;
 using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using System.Windows.Controls;
 using System.Windows.Input;
 using System.Windows.Media;
 using AIStudio.Wpf.DiagramDesigner.Enums;
diff --git a/Directory.Build.Props b/Directory.Build.Props
index 4d76575..8167a32 100644
--- a/Directory.Build.Props
+++ b/Directory.Build.Props
@@ -1,7 +1,7 @@
 <Project>
   <!-- Project properties -->
 	<PropertyGroup>
-    <TargetFrameworks>net6.0-windows</TargetFrameworks>
+    <TargetFrameworks>net461;net5.0-windows;net6.0-windows</TargetFrameworks>
 	</PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">