diff --git a/FDTD/operator.cpp b/FDTD/operator.cpp
index 3fcca39..545cdeb 100644
--- a/FDTD/operator.cpp
+++ b/FDTD/operator.cpp
@@ -433,6 +433,8 @@ void Operator::DumpOperator2File(string filename)
 	vtk_io->SetMeshLines(discLines,numLines,discLines_scaling);
 	vtk_io->SetHeader("openEMS - Operator dump");
 
+	vtk_io->SetNativeDump(true);
+
 	vtk_io->AddVectorField("vv",vv_temp,numLines);
 	Delete_N_3DArray(vv_temp,numLines);
 	vtk_io->AddVectorField("vi",vi_temp,numLines);
@@ -528,6 +530,8 @@ void Operator::DumpPEC2File( string filename )
 	vtk_io->SetMeshLines(discLines,numLines,scaling);
 	vtk_io->SetHeader("openEMS - PEC dump");
 
+	vtk_io->SetNativeDump(true);
+
 	vtk_io->AddVectorField("PEC",pec,numLines);
 	Delete_N_3DArray(pec,numLines);
 
@@ -576,6 +580,8 @@ void Operator::DumpMaterial2File(string filename)
 	vtk_io->SetMeshLines(discLines,numLines,discLines_scaling);
 	vtk_io->SetHeader("openEMS - material dump");
 
+	vtk_io->SetNativeDump(true);
+
 	vtk_io->AddVectorField("epsilon",epsilon,numLines);
 	Delete_N_3DArray(epsilon,numLines);
 	vtk_io->AddVectorField("mue",mue,numLines);