diff --git a/src/GUI/NETGENPluginGUI_HypothesisCreator.cxx b/src/GUI/NETGENPluginGUI_HypothesisCreator.cxx
index 4b1f71f..ce34140 100644
--- a/src/GUI/NETGENPluginGUI_HypothesisCreator.cxx
+++ b/src/GUI/NETGENPluginGUI_HypothesisCreator.cxx
@@ -329,7 +329,7 @@ void NETGENPluginGUI_HypothesisCreator::retrieveParams() const
 
   // update widgets
   bool isCustom = (myFineness->currentIndex() == UserDefined);
-  bool isSurfaceCurvature = (mySurfaceCurvature->checkState() == Qt::Checked);
+  bool isSurfaceCurvature = (mySurfaceCurvature ? mySurfaceCurvature->checkState() == Qt::Checked : false);
   myFineness->setEnabled(isSurfaceCurvature);
   myGrowthRate->setEnabled(isCustom && isSurfaceCurvature);
   if ( myNbSegPerEdge )
@@ -561,7 +561,7 @@ bool NETGENPluginGUI_HypothesisCreator::readParamsFromWidgets( NetgenHypothesisD
 
 void NETGENPluginGUI_HypothesisCreator::onSurfaceCurvatureChanged()
 {
-  bool isSurfaceCurvature = (mySurfaceCurvature->checkState() == Qt::Checked);
+  bool isSurfaceCurvature = (mySurfaceCurvature ? mySurfaceCurvature->checkState() == Qt::Checked : false);
   bool isCustom = (myFineness->currentIndex() == UserDefined);
   myFineness->setEnabled(isSurfaceCurvature);
   myGrowthRate->setEnabled(isCustom && isSurfaceCurvature);