diff --git a/src/Cake.Common/Tools/DotNet/Test/DotNetTester.cs b/src/Cake.Common/Tools/DotNet/Test/DotNetTester.cs
index 1a24fb0e68..4796f8ee75 100644
--- a/src/Cake.Common/Tools/DotNet/Test/DotNetTester.cs
+++ b/src/Cake.Common/Tools/DotNet/Test/DotNetTester.cs
@@ -231,7 +231,7 @@ private static DotNetTestPathType AutoDetectPathType(string project)
             var extension = FilePath.FromString(project).GetExtension().ToLowerInvariant();
             return extension switch
             {
-                ".sln" => DotNetTestPathType.Solution,
+                ".sln" or ".slnx" => DotNetTestPathType.Solution,
                 ".csproj" or ".vbproj" or ".fsproj" or ".vcxproj" => DotNetTestPathType.Project,
                 _ => DotNetTestPathType.None // Default to legacy behavior for unknown extensions
             };