diff --git a/FDTD/operator_cylinder.cpp b/FDTD/operator_cylinder.cpp
index bc42baa..5beaf56 100644
--- a/FDTD/operator_cylinder.cpp
+++ b/FDTD/operator_cylinder.cpp
@@ -76,13 +76,13 @@ string Operator_Cylinder::GetDirName(int ny) const
 	return "";
 }
 
-double Operator_Cylinder::GetMeshDelta(int n, int* pos, bool dualMesh) const
+double Operator_Cylinder::GetMeshDelta(int n, const int* pos, bool dualMesh) const
 {
 	double delta = Operator::GetMeshDelta(n,pos,dualMesh);
 	if (delta==0) return delta;
 	if (n==1)
 	{
-		return delta * GetDiscLine(n,pos[0],dualMesh);
+		return delta * GetDiscLine(0,pos[0],dualMesh);
 	}
 	return delta;
 }
@@ -211,7 +211,7 @@ void Operator_Cylinder::ApplyMagneticBC(bool* dirs)
 	}
 	if (CC_R0_included)
 	{
-		dirs[2]=0;  //no PMC in r_min directions...
+		dirs[0]=0;  //no PMC in r_min directions...
 	}
 	Operator::ApplyMagneticBC(dirs);
 }
diff --git a/FDTD/operator_cylinder.h b/FDTD/operator_cylinder.h
index df90261..30af198 100644
--- a/FDTD/operator_cylinder.h
+++ b/FDTD/operator_cylinder.h
@@ -39,7 +39,7 @@ public:
 	virtual string GetDirName(int ny) const;
 
 	//! Get the mesh delta times the grid delta for a 3D position, including radius corrected alpha-mesh width
-	virtual double GetMeshDelta(int n, int* pos, bool dualMesh=false) const;
+	virtual double GetMeshDelta(int n, const int* pos, bool dualMesh=false) const;
 
 	bool GetClosedAlpha() const {return CC_closedAlpha;}
 	bool GetR0Included() const {return CC_R0_included;}