diff --git a/FDTD/operator_cylinder.cpp b/FDTD/operator_cylinder.cpp
index 4a53d9b..342415f 100644
--- a/FDTD/operator_cylinder.cpp
+++ b/FDTD/operator_cylinder.cpp
@@ -88,6 +88,15 @@ int Operator_Cylinder::CalcECOperator( DebugFlags debugFlags )
 	return rc;
 }
 
+double Operator_Cylinder::CalcTimestep()
+{
+	if (discLines[0][0]==0.0)
+		// use conservative timestep for a mesh including the r==0 singularity
+		m_TimeStepVar = 1;
+
+	return Operator::CalcTimestep();
+}
+
 inline unsigned int Operator_Cylinder::GetNumberOfLines(int ny, bool full) const
 {
 	if (full)
@@ -493,9 +502,6 @@ bool Operator_Cylinder::SetupCSXGrid(CSRectGrid* grid)
 		if (g_settings.GetVerboseLevel()>0)
 			cout << "Operator_Cylinder::SetupCSXGrid: r=0 included..." << endl;
 		CC_R0_included = CC_closedAlpha;  //needed for correct ec-calculation, deactivate if closed cylinder is false... --> E_r = 0 anyways
-
-		// use conservative timestep for a mesh including the r==0 singularity
-		m_TimeStepVar = 1;
 	}
 
 #ifdef MPI_SUPPORT
diff --git a/FDTD/operator_cylinder.h b/FDTD/operator_cylinder.h
index 5d4b0e4..152f618 100644
--- a/FDTD/operator_cylinder.h
+++ b/FDTD/operator_cylinder.h
@@ -105,7 +105,7 @@ protected:
 	virtual double GetMaterial(int ny, const double coords[3], int MatType, vector<CSPrimitives*> vPrims, bool markAsUsed=true) const;
 
 	virtual int CalcECOperator( DebugFlags debugFlags = None );
-
+	virtual double CalcTimestep();
 	bool CC_closedAlpha;
 	bool CC_R0_included;
 	Operator_Ext_Cylinder* m_Cyl_Ext;