diff --git a/src/Testing/ref/Microsoft.AspNetCore.Testing.net46.cs b/src/Testing/ref/Microsoft.AspNetCore.Testing.net46.cs
index af28ec60e0..e737371a8c 100644
--- a/src/Testing/ref/Microsoft.AspNetCore.Testing.net46.cs
+++ b/src/Testing/ref/Microsoft.AspNetCore.Testing.net46.cs
@@ -295,6 +295,7 @@ namespace Microsoft.AspNetCore.Testing
         public string TestName { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
         public static string GetAssemblyBaseDirectory(System.Reflection.Assembly assembly, string baseDirectory = null) { throw null; }
         public static string GetOutputDirectory(System.Reflection.Assembly assembly) { throw null; }
+        public static bool GetPreserveExistingLogsInOutput(System.Reflection.Assembly assembly) { throw null; }
         public static string GetTestClassName(System.Type type) { throw null; }
         public static string GetTestMethodName(System.Reflection.MethodInfo method, object[] arguments) { throw null; }
         public string GetUniqueFileName(string prefix, string extension) { throw null; }
@@ -307,8 +308,9 @@ namespace Microsoft.AspNetCore.Testing
     [System.AttributeUsageAttribute(System.AttributeTargets.Assembly, AllowMultiple=false, Inherited=true)]
     public partial class TestOutputDirectoryAttribute : System.Attribute
     {
-        public TestOutputDirectoryAttribute(string targetFramework, string baseDirectory = null) { }
+        public TestOutputDirectoryAttribute(string preserveExistingLogsInOutput, string targetFramework, string baseDirectory = null) { }
         public string BaseDirectory { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
+        public bool PreserveExistingLogsInOutput { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
         public string TargetFramework { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
     }
     [System.ObsoleteAttribute("This API is obsolete and the pattern its usage encouraged should not be used anymore. See https://github.com/aspnet/Extensions/issues/1697 for details.")]
diff --git a/src/Testing/ref/Microsoft.AspNetCore.Testing.netstandard2.0.cs b/src/Testing/ref/Microsoft.AspNetCore.Testing.netstandard2.0.cs
index af28ec60e0..e737371a8c 100644
--- a/src/Testing/ref/Microsoft.AspNetCore.Testing.netstandard2.0.cs
+++ b/src/Testing/ref/Microsoft.AspNetCore.Testing.netstandard2.0.cs
@@ -295,6 +295,7 @@ namespace Microsoft.AspNetCore.Testing
         public string TestName { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
         public static string GetAssemblyBaseDirectory(System.Reflection.Assembly assembly, string baseDirectory = null) { throw null; }
         public static string GetOutputDirectory(System.Reflection.Assembly assembly) { throw null; }
+        public static bool GetPreserveExistingLogsInOutput(System.Reflection.Assembly assembly) { throw null; }
         public static string GetTestClassName(System.Type type) { throw null; }
         public static string GetTestMethodName(System.Reflection.MethodInfo method, object[] arguments) { throw null; }
         public string GetUniqueFileName(string prefix, string extension) { throw null; }
@@ -307,8 +308,9 @@ namespace Microsoft.AspNetCore.Testing
     [System.AttributeUsageAttribute(System.AttributeTargets.Assembly, AllowMultiple=false, Inherited=true)]
     public partial class TestOutputDirectoryAttribute : System.Attribute
     {
-        public TestOutputDirectoryAttribute(string targetFramework, string baseDirectory = null) { }
+        public TestOutputDirectoryAttribute(string preserveExistingLogsInOutput, string targetFramework, string baseDirectory = null) { }
         public string BaseDirectory { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
+        public bool PreserveExistingLogsInOutput { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
         public string TargetFramework { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
     }
     [System.ObsoleteAttribute("This API is obsolete and the pattern its usage encouraged should not be used anymore. See https://github.com/aspnet/Extensions/issues/1697 for details.")]
diff --git a/src/Testing/src/TestFileOutputContext.cs b/src/Testing/src/TestFileOutputContext.cs
index 496a1379fb..fb79fd7bf7 100644
--- a/src/Testing/src/TestFileOutputContext.cs
+++ b/src/Testing/src/TestFileOutputContext.cs
@@ -93,6 +93,12 @@ namespace Microsoft.AspNetCore.Testing
             return Path.Combine(baseDirectory, assembly.GetName().Name, attribute.TargetFramework);
         }
 
+        public static bool GetPreserveExistingLogsInOutput(Assembly assembly)
+        {
+            var attribute = assembly.GetCustomAttributes().OfType<TestOutputDirectoryAttribute>().FirstOrDefault();
+            return attribute.PreserveExistingLogsInOutput;
+        }
+
         public static string GetTestClassName(Type type)
         {
             var shortNameAttribute =
diff --git a/src/Testing/src/TestOutputDirectoryAttribute.cs b/src/Testing/src/TestOutputDirectoryAttribute.cs
index 4ae8cea054..b1895c1d92 100644
--- a/src/Testing/src/TestOutputDirectoryAttribute.cs
+++ b/src/Testing/src/TestOutputDirectoryAttribute.cs
@@ -8,13 +8,15 @@ namespace Microsoft.AspNetCore.Testing
     [AttributeUsage(AttributeTargets.Assembly, AllowMultiple = false, Inherited = true)]
     public class TestOutputDirectoryAttribute : Attribute
     {
-        public TestOutputDirectoryAttribute(string targetFramework, string baseDirectory = null)
+        public TestOutputDirectoryAttribute(string preserveExistingLogsInOutput, string targetFramework, string baseDirectory = null)
         {
             TargetFramework = targetFramework;
             BaseDirectory = baseDirectory;
+            PreserveExistingLogsInOutput = bool.Parse(preserveExistingLogsInOutput);
         }
 
         public string BaseDirectory { get; }
         public string TargetFramework { get; }
+        public bool PreserveExistingLogsInOutput { get; }
     }
 }