diff --git a/test/TwinGet.AutomationInterface.Test/TestUtils/TestTwincatProject.cs b/test/TwinGet.AutomationInterface.Test/TestUtils/TestTwincatProject.cs
index 877d8fe..d9e3b8a 100644
--- a/test/TwinGet.AutomationInterface.Test/TestUtils/TestTwincatProject.cs
+++ b/test/TwinGet.AutomationInterface.Test/TestUtils/TestTwincatProject.cs
@@ -24,15 +24,12 @@ public TestTwincatProject(string name, string absolutePath)
 
             using (StringReader reader = new(xmlContent))
             {
-                TcSmProjectData tcSmProject = serializer.Deserialize(reader) as TcSmProjectData ?? throw new InvalidProjectFileFormat("The format of TwinCAT project file is invalid.", absolutePath);
-
-                if (tcSmProject.Project.Plc?.Projects is not null)
-                {
-                    _plcProjects.AddRange(from ProjectElement project in tcSmProject.Project.Plc.Projects
-                                          let plcProject = new TestPlcProject(Path.Join(rootDir, project.PrjFilePath))
-                                          where plcProject is not null
-                                          select plcProject);
-                }
+                TcSmProjectData tcSmProject = serializer.Deserialize(reader) as TcSmProjectData ?? throw new InvalidProjectFileFormat("The format of TwinCAT project file is invalid.", absolutePath);
+
+                var plcProjects = tcSmProject.Project.Plc?.Projects?
+                                .Select(x => new TestPlcProject(Path.Join(rootDir, x.PrjFilePath)));
+
+                _plcProjects = new(plcProjects ?? []);
             }
         }
     }