diff --git a/Netch/Controllers/PcapController.cs b/Netch/Controllers/PcapController.cs
index 1bd8c467..7d239dea 100644
--- a/Netch/Controllers/PcapController.cs
+++ b/Netch/Controllers/PcapController.cs
@@ -47,7 +47,7 @@ namespace Netch.Controllers
             Global.MainForm.BeginInvoke(new Action(() =>
             {
                 if (!_form!.IsDisposed)
-                    _form!.richTextBox1.AppendText(line + "\n");
+                    _form.richTextBox1.AppendText(line + "\n");
             }));
         }
 
diff --git a/Netch/Models/Mode.cs b/Netch/Models/Mode.cs
index 380c2372..5d301050 100644
--- a/Netch/Models/Mode.cs
+++ b/Netch/Models/Mode.cs
@@ -79,7 +79,7 @@ namespace Netch.Models
                         relativePath.Replace(">", "");
                         relativePath.Replace(".h", ".txt");
 
-                        var mode = Global.Modes.FirstOrDefault(m => m!.FullName != null && m.RelativePath!.Equals(relativePath.ToString()));
+                        var mode = Global.Modes.FirstOrDefault(m => m.FullName != null && m.RelativePath!.Equals(relativePath.ToString()));
 
                         if (mode == null)
                             throw new MessageException($"{relativePath} file included in {Remark} not found");
diff --git a/Netch/Netch.csproj b/Netch/Netch.csproj
index ba6378b3..41eb4312 100644
--- a/Netch/Netch.csproj
+++ b/Netch/Netch.csproj
@@ -44,6 +44,10 @@
         <PackageReference Include="MaxMind.GeoIP2" Version="4.0.1" />
         <PackageReference Include="Microsoft.Diagnostics.Tracing.TraceEvent" Version="2.0.66" GeneratePathProperty="true" />
         <PackageReference Include="Microsoft.Win32.Registry" Version="5.0.0" />
+        <PackageReference Include="Nullable.Extended.Analyzer" Version="1.2.4089">
+          <PrivateAssets>all</PrivateAssets>
+          <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+        </PackageReference>
         <PackageReference Include="System.Collections.Immutable" Version="5.0.0" />
         <PackageReference Include="System.Reflection.Metadata" Version="5.0.0" />
         <PackageReference Include="System.Resources.Extensions" Version="5.0.0" />