diff --git a/src/Framework/AspNetCoreAnalyzers/src/Analyzers/Http/RequestDelegateReturnTypeAnalyzer.cs b/src/Framework/AspNetCoreAnalyzers/src/Analyzers/Http/RequestDelegateReturnTypeAnalyzer.cs
index 9ce7c69a9ecb..a8b52ec826b1 100644
--- a/src/Framework/AspNetCoreAnalyzers/src/Analyzers/Http/RequestDelegateReturnTypeAnalyzer.cs
+++ b/src/Framework/AspNetCoreAnalyzers/src/Analyzers/Http/RequestDelegateReturnTypeAnalyzer.cs
@@ -55,6 +55,12 @@ public override void Initialize(AnalysisContext context)
 if (item is IReturnOperation returnOperation &&
 returnOperation.ReturnedValue is { } returnedValue)
 {
+ // Skip return operations that belong to nested anonymous functions
+ if (IsReturnFromNestedAnonymousFunction(returnOperation, anonymousFunction))
+ {
+ continue;
+ }
+
 var resolvedOperation = WalkDownConversion(returnedValue);
 var returnType = resolvedOperation.Type;
 
@@ -81,6 +87,32 @@ private static void AddDiagnosticWarning(OperationAnalysisContext context, Locat
 ((INamedTypeSymbol)returnType).TypeArguments[0].ToString()));
 }
 
+ private static bool IsReturnFromNestedAnonymousFunction(IReturnOperation returnOperation, IAnonymousFunctionOperation targetAnonymousFunction)
+ {
+ // Walk up the parent chain from the return operation to see if we encounter
+ // a nested anonymous function before reaching the target anonymous function
+ var current = returnOperation.Parent;
+ while (current != null)
+ {
+ if (ReferenceEquals(current, targetAnonymousFunction))
+ {
+ // We reached the target anonymous function without finding a nested one
+ return false;
+ }
+
+ if (current is IAnonymousFunctionOperation)
+ {
+ // We found a nested anonymous function before reaching the target
+ return true;
+ }
+
+ current = current.Parent;
+ }
+
+ // This shouldn't happen in valid code, but return true to be safe
+ return true;
+ }
+
 private static IOperation WalkDownConversion(IOperation operation)
 {
 while (operation is IConversionOperation conversionOperation)
diff --git a/src/Framework/AspNetCoreAnalyzers/test/Http/RequestDelegateReturnTypeAnalyzerTests.cs b/src/Framework/AspNetCoreAnalyzers/test/Http/RequestDelegateReturnTypeAnalyzerTests.cs
index be5fe3adcea4..049e1e360df7 100644
--- a/src/Framework/AspNetCoreAnalyzers/test/Http/RequestDelegateReturnTypeAnalyzerTests.cs
+++ b/src/Framework/AspNetCoreAnalyzers/test/Http/RequestDelegateReturnTypeAnalyzerTests.cs
@@ -347,6 +347,42 @@ await VerifyCS.VerifyAnalyzerAsync(@"
 webApp.MapGet(""/"", HttpMethod);
 
 static Task HttpMethod(HttpContext context) => Task.CompletedTask;
+");
+ }
+
+ [Fact]
+ public async Task AnonymousDelegate_RequestDelegate_ReturnType_InNestedAnonymousDelegate_DoesNotReportDiagnostics()
+ {
+ await VerifyCS.VerifyAnalyzerAsync(@"
+using System;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Builder;
+var webApp = WebApplication.Create();
+webApp.Run((context) =>
+{
+ Func<task<datetime>> _ = () => Task.FromResult(DateTime.Now);
+ return Task.CompletedTask;
+});
+");
+ }
+
+ [Fact]
+ public async Task AnonymousDelegate_RequestDelegate_ReturnType_InNestedLambdaPassedToMethod_DoesNotReportDiagnostics()
+ {
+ // This test simulates the real-world case from the issue where a lambda
+ // returning Task<stream> is passed to ThrowsAsync as Func<task<stream>>
+ await VerifyCS.VerifyAnalyzerAsync(@"
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Builder;
+var webApp = WebApplication.Create();
+webApp.Run(async (context) =>
+{
+ await SomeMethodThatTakesFunc(() => Task.FromResult(Stream.Null));
+});
+
+static Task SomeMethodThatTakesFunc(Func<task<stream>> func) => Task.CompletedTask;
 ");
 }
 }
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