diff --git a/src/TestApp/ZeroQL.TestApp/Generated/GraphQL.g.cs b/src/TestApp/ZeroQL.TestApp/Generated/GraphQL.g.cs
index 6f953d3..f65da3b 100644
--- a/src/TestApp/ZeroQL.TestApp/Generated/GraphQL.g.cs
+++ b/src/TestApp/ZeroQL.TestApp/Generated/GraphQL.g.cs
@@ -1,4 +1,4 @@
-// 291685ad31ee73dba6a2172b2f6dcc25
+// f63f7a964078b30c19f6630749226655
 // This file generated for ZeroQL.
 // <auto-generated/>
 #pragma warning disable 8618
diff --git a/src/ZeroQL.SourceGenerators/Generator/GraphQLLambdaIncrementalSourceGenerator.cs b/src/ZeroQL.SourceGenerators/Generator/GraphQLLambdaIncrementalSourceGenerator.cs
index 41f9f1d..ac1d8b4 100644
--- a/src/ZeroQL.SourceGenerators/Generator/GraphQLLambdaIncrementalSourceGenerator.cs
+++ b/src/ZeroQL.SourceGenerators/Generator/GraphQLLambdaIncrementalSourceGenerator.cs
@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Threading;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
@@ -15,19 +17,33 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
         var invocations = context.SyntaxProvider
             .CreateSyntaxProvider(FindMethods, (c, ct) => (Invocation: (InvocationExpressionSyntax)c.Node, c.SemanticModel));
 
-        context.RegisterImplementationSourceOutput(invocations, (sourceContext, data) => 
-            Utils.ErrorWrapper(sourceContext, data.Invocation,() => GenerateSource(sourceContext, data)));
+        var collectedInvocations = invocations.Collect();
+
+        context.RegisterImplementationSourceOutput(collectedInvocations, GenerateSource);
     }
-    
+
     private void GenerateSource(
         SourceProductionContext context,
-        (InvocationExpressionSyntax Invocation, SemanticModel SemanticModel) input)
+        ImmutableArray<(InvocationExpressionSyntax Invocation, SemanticModel SemanticModel)> invocations)
     {
-        var (invocation, semanticModel) = input;
-        if (context.CancellationToken.IsCancellationRequested)
+        var processed = new HashSet<string>();
+        foreach (var input in invocations)
         {
-            return;
+            var (invocation, semanticModel) = input;
+            if (context.CancellationToken.IsCancellationRequested)
+            {
+                return;
+            }
+
+            Utils.ErrorWrapper(
+                context,
+                invocation,
+                () => GenerateFile(context, invocation, semanticModel, processed));
         }
+    }
+
+    private static void GenerateFile(SourceProductionContext context, InvocationExpressionSyntax? invocation, SemanticModel? semanticModel, HashSet<string> processed)
+    {
 
         var resolver = new GraphQLLambdaLikeContextResolver();
         var (lambdaContext, error) = resolver.Resolve(invocation, semanticModel, context.CancellationToken).Unwrap();
@@ -65,6 +81,12 @@ private void GenerateSource(
             return;
         }
 
+        if (processed.Contains(lambdaContext.OperationHash))
+        {
+            return;
+        }
+
+        processed.Add(lambdaContext.OperationHash);
         context.AddSource($"ZeroQLModuleInitializer.{lambdaContext.OperationHash}.g.cs", source);
     }
 
diff --git a/src/ZeroQL.SourceGenerators/Generator/GraphQLRequestIncrementalSourceGenerator.cs b/src/ZeroQL.SourceGenerators/Generator/GraphQLRequestIncrementalSourceGenerator.cs
index 7096d59..2ca1f0e 100644
--- a/src/ZeroQL.SourceGenerators/Generator/GraphQLRequestIncrementalSourceGenerator.cs
+++ b/src/ZeroQL.SourceGenerators/Generator/GraphQLRequestIncrementalSourceGenerator.cs
@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Linq;
 using System.Threading;
 using Microsoft.CodeAnalysis;
@@ -18,14 +20,27 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
             .CreateSyntaxProvider(FindGraphQLRequests,
                 (c, ct) => (Record: (RecordDeclarationSyntax)c.Node, c.SemanticModel));
 
-        context.RegisterImplementationSourceOutput(invocations, (sourceContext, data) =>
-            Utils.ErrorWrapper(sourceContext, data.Record, () => GenerateSource(sourceContext, data)));
+        var collectedInvocations = invocations.Collect();
+
+        context.RegisterImplementationSourceOutput(collectedInvocations, GenerateSource);
     }
 
     private void GenerateSource(SourceProductionContext context,
-        (RecordDeclarationSyntax Record, SemanticModel SemanticModel) input)
+        ImmutableArray<(RecordDeclarationSyntax Record, SemanticModel SemanticModel)> invocations)
+    {
+        var processed = new HashSet<string>();
+        foreach (var input in invocations)
+        {
+            var (record, semanticModel) = input;
+            Utils.ErrorWrapper(
+                context,
+                record,
+                () => GenerateFile(context, semanticModel, record, processed));
+        }
+    }
+
+    private void GenerateFile(SourceProductionContext context, SemanticModel semanticModel, RecordDeclarationSyntax record, HashSet<string> processed)
     {
-        var (record, semanticModel) = input;
         var recordSymbol = semanticModel.GetDeclaredSymbol(record);
         var graphQLRequest = semanticModel.Compilation.GetTypeByMetadataName("ZeroQL.GraphQL`2");
 
@@ -67,6 +82,12 @@ private void GenerateSource(SourceProductionContext context,
             return;
         }
 
+        if (processed.Contains(requestLikeContext.OperationHash))
+        {
+            return;
+        }
+
+        processed.Add(requestLikeContext.OperationHash);
         context.AddSource($"ZeroQLModuleInitializer.{requestLikeContext.OperationHash}.g.cs", source);
     }
 
diff --git a/src/ZeroQL.SourceGenerators/Resolver/GraphQLSourceResolver.cs b/src/ZeroQL.SourceGenerators/Resolver/GraphQLSourceResolver.cs
index 38e76e8..e679483 100644
--- a/src/ZeroQL.SourceGenerators/Resolver/GraphQLSourceResolver.cs
+++ b/src/ZeroQL.SourceGenerators/Resolver/GraphQLSourceResolver.cs
@@ -27,6 +27,8 @@ public static string Resolve(
 using ZeroQL.Json;
 using ZeroQL.Internal;
 
+#nullable enable
+
 namespace {semanticModel.Compilation.Assembly.Name}
 {{
     {SourceGeneratorInfo.CodeGenerationAttribute}
@@ -44,9 +46,9 @@ public static void Init()
             }};
         }}
 
-        public static async Task<GraphQLResult<{context.QueryTypeName}>> Execute(IGraphQLClient qlClient, string queryKey, object variablesObject, CancellationToken cancellationToken)
+        public static async Task<GraphQLResult<{context.QueryTypeName}>> Execute(IGraphQLClient qlClient, string queryKey, object? variablesObject, CancellationToken cancellationToken)
         {{
-            var variables = ({context.RequestExecutorInputSymbol.ToGlobalName()})variablesObject;
+            var variables = ({context.RequestExecutorInputSymbol.ToGlobalName()})variablesObject!;
             var qlResponse = await qlClient.QueryPipeline.ExecuteAsync<{context.QueryTypeName}>(qlClient.HttpClient, queryKey, variablesObject, cancellationToken, queryRequest => 
             {{
                 {GraphQLUploadResolver.GenerateRequestPreparations(graphQLInputTypeSafeName, typeInfo)}
diff --git a/src/ZeroQL.Tests/CLI/ModuleInitializer.cs b/src/ZeroQL.Tests/CLI/ModuleInitializer.cs
new file mode 100644
index 0000000..645392b
--- /dev/null
+++ b/src/ZeroQL.Tests/CLI/ModuleInitializer.cs
@@ -0,0 +1,12 @@
+using System.Runtime.CompilerServices;
+
+namespace ZeroQL.Tests.CLI;
+
+public static class ModuleInitializer
+{
+    [ModuleInitializer]
+    public static void Initialize()
+    {
+        VerifyNodaTime.Enable();
+    }
+}
\ No newline at end of file
diff --git a/src/ZeroQL.Tests/Core/IntegrationTest.cs b/src/ZeroQL.Tests/Core/IntegrationTest.cs
index 03d4ee6..76a7d15 100644
--- a/src/ZeroQL.Tests/Core/IntegrationTest.cs
+++ b/src/ZeroQL.Tests/Core/IntegrationTest.cs
@@ -1,6 +1,8 @@
 using Xunit;
 using ZeroQL.Tests.Core.Fixtures;
 
+[assembly: CollectionBehavior(DisableTestParallelization = true)]
+
 namespace ZeroQL.Tests.Core;
 
 [Collection("Integration")]
diff --git a/src/ZeroQL.Tests/Data/TestProject.cs b/src/ZeroQL.Tests/Data/TestProject.cs
index 3b68d13..5242c9d 100644
--- a/src/ZeroQL.Tests/Data/TestProject.cs
+++ b/src/ZeroQL.Tests/Data/TestProject.cs
@@ -17,7 +17,6 @@ public static class TestProject
 
     static TestProject()
     {
-        VerifyNodaTime.Enable();
         var manager = new AnalyzerManager();
         manager.GetProject(@"../../../../TestApp/ZeroQL.TestApp/ZeroQL.TestApp.csproj");
         Workspace = manager.GetWorkspace();
diff --git a/src/ZeroQL.Tests/SourceGeneration/QueryTests.LambdaModuleInitializerGenerated.verified.txt b/src/ZeroQL.Tests/SourceGeneration/QueryTests.LambdaModuleInitializerGenerated.verified.txt
index 5b02e6c..6da446f 100644
--- a/src/ZeroQL.Tests/SourceGeneration/QueryTests.LambdaModuleInitializerGenerated.verified.txt
+++ b/src/ZeroQL.Tests/SourceGeneration/QueryTests.LambdaModuleInitializerGenerated.verified.txt
@@ -13,6 +13,8 @@ using ZeroQL.Stores;
 using ZeroQL.Json;
 using ZeroQL.Internal;
 
+#nullable enable
+
 namespace ZeroQL.TestApp
 {
     [System.CodeDom.Compiler.GeneratedCode("ZeroQL", "1.0.0.0")]
@@ -30,9 +32,9 @@ namespace ZeroQL.TestApp
             };
         }
 
-        public static async Task<GraphQLResult<global::GraphQL.TestServer.Query>> Execute(IGraphQLClient qlClient, string queryKey, object variablesObject, CancellationToken cancellationToken)
+        public static async Task<GraphQLResult<global::GraphQL.TestServer.Query>> Execute(IGraphQLClient qlClient, string queryKey, object? variablesObject, CancellationToken cancellationToken)
         {
-            var variables = (global::ZeroQL.Unit)variablesObject;
+            var variables = (global::ZeroQL.Unit)variablesObject!;
             var qlResponse = await qlClient.QueryPipeline.ExecuteAsync<global::GraphQL.TestServer.Query>(qlClient.HttpClient, queryKey, variablesObject, cancellationToken, queryRequest => 
             {