diff --git a/Pal.Client/Net/GrpcLogger.cs b/Pal.Client/Net/GrpcLogger.cs
index ec68920..eb900b1 100644
--- a/Pal.Client/Net/GrpcLogger.cs
+++ b/Pal.Client/Net/GrpcLogger.cs
@@ -14,7 +14,9 @@ namespace Pal.Client.Net
             _name = name;
         }
 
-        public IDisposable BeginScope<TState>(TState state) => NullScope.Instance;
+        public IDisposable BeginScope<TState>(TState state) 
+            where TState: notnull
+            => NullScope.Instance;
 
         public bool IsEnabled(LogLevel logLevel) => logLevel != LogLevel.None;
 
diff --git a/Pal.Client/Pal.Client.csproj b/Pal.Client/Pal.Client.csproj
index 919856d..e949dde 100644
--- a/Pal.Client/Pal.Client.csproj
+++ b/Pal.Client/Pal.Client.csproj
@@ -3,7 +3,7 @@
 	<PropertyGroup>
 		<TargetFramework>net6.0-windows</TargetFramework>
 		<LangVersion>9.0</LangVersion>
-		<Version>1.19</Version>
+		<Version>1.20</Version>
 		<Nullable>enable</Nullable>
 	</PropertyGroup>