diff --git a/qucs/qucs/dialogs/sweepdialog.cpp b/qucs/qucs/dialogs/sweepdialog.cpp
index 4e40f29d39..2174f69627 100644
--- a/qucs/qucs/dialogs/sweepdialog.cpp
+++ b/qucs/qucs/dialogs/sweepdialog.cpp
@@ -125,8 +125,9 @@ void SweepDialog::slotNewValue(int)
 {
   DataX *pD = pGraph->cPointsX.first();
   int Factor = 1, Index = 0;
-  for(mySpinBox *pb = BoxList.first(); pb!=0; pb = BoxList.next()) {
-    Index  += pb->value() * Factor;
+  QList<mySpinBox *>::const_iterator it;
+  for(it = BoxList.constBegin(); it != BoxList.constEnd(); it++) {
+    Index  += (*it)->value() * Factor;
     Factor *= pD->count;
   }
   Index *= 2;  // because of complex values
diff --git a/qucs/qucs/dialogs/sweepdialog.h b/qucs/qucs/dialogs/sweepdialog.h
index 21db4648af..b512a8d54d 100644
--- a/qucs/qucs/dialogs/sweepdialog.h
+++ b/qucs/qucs/dialogs/sweepdialog.h
@@ -21,6 +21,7 @@
 #include <QDialog>
 #include <QRegExp>
 #include <Q3PtrList>
+#include <QList>
 
 #include <QSpinBox>
 #include <QGridLayout>
@@ -61,7 +62,7 @@ private slots:
   Graph* setBiasPoints();
 
   QGridLayout *all;   // the mother of all widgets
-  Q3PtrList<mySpinBox> BoxList;
+  QList<mySpinBox *> BoxList;
 
   Graph *pGraph;
   Schematic *Doc;