diff --git a/Polyhedron/demo/Polyhedron/Plugins/Classification/Cluster_classification.cpp b/Polyhedron/demo/Polyhedron/Plugins/Classification/Cluster_classification.cpp
index 94bbef928e2..5c5fedfafb5 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/Classification/Cluster_classification.cpp
+++ b/Polyhedron/demo/Polyhedron/Plugins/Classification/Cluster_classification.cpp
@@ -818,9 +818,9 @@ void Cluster_classification::train(int classifier, const QMultipleInputDialog& d
     if (m_ethz != NULL)
       delete m_ethz;
     m_ethz = new ETHZ_random_forest (m_labels, m_features);
-    m_ethz->train(training, true,
-                  dialog.get<QSpinBox>("num_trees")->value(),
-                  dialog.get<QSpinBox>("max_depth")->value());
+    m_ethz->train<Concurrency_tag>(training, true,
+                                   dialog.get<QSpinBox>("num_trees")->value(),
+                                   dialog.get<QSpinBox>("max_depth")->value());
     CGAL::Classification::classify<Concurrency_tag> (m_clusters,
                                                      m_labels, *m_ethz,
                                                      indices, m_label_probabilities);
diff --git a/Polyhedron/demo/Polyhedron/Plugins/Classification/Point_set_item_classification.cpp b/Polyhedron/demo/Polyhedron/Plugins/Classification/Point_set_item_classification.cpp
index 44a58ef4236..e2146d9343a 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/Classification/Point_set_item_classification.cpp
+++ b/Polyhedron/demo/Polyhedron/Plugins/Classification/Point_set_item_classification.cpp
@@ -727,9 +727,9 @@ void Point_set_item_classification::train(int classifier, const QMultipleInputDi
     if (m_ethz != NULL)
       delete m_ethz;
     m_ethz = new ETHZ_random_forest (m_labels, m_features);
-    m_ethz->train(training, true,
-                  dialog.get<QSpinBox>("num_trees")->value(),
-                  dialog.get<QSpinBox>("max_depth")->value());
+    m_ethz->train<Concurrency_tag>(training, true,
+                                   dialog.get<QSpinBox>("num_trees")->value(),
+                                   dialog.get<QSpinBox>("max_depth")->value());
     CGAL::Classification::classify<Concurrency_tag> (*(m_points->point_set()),
                                                      m_labels, *m_ethz,
                                                      indices, m_label_probabilities);
diff --git a/Polyhedron/demo/Polyhedron/Plugins/Classification/Point_set_item_classification.h b/Polyhedron/demo/Polyhedron/Plugins/Classification/Point_set_item_classification.h
index 3a428b523ef..af9412c6a73 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/Classification/Point_set_item_classification.h
+++ b/Polyhedron/demo/Polyhedron/Plugins/Classification/Point_set_item_classification.h
@@ -333,10 +333,11 @@ class Point_set_item_classification : public Item_classification_base
   {
     std::vector<int> indices (m_points->point_set()->size(), -1);
 
+    m_label_probabilities.clear();
     if (method == 0)
       CGAL::Classification::classify<Concurrency_tag> (*(m_points->point_set()),
                                                        m_labels, classifier,
-                                                       indices);
+                                                       indices, m_label_probabilities);
     else if (method == 1)
     {
       if (m_clusters.empty()) // Use real local smoothing
diff --git a/Polyhedron/demo/Polyhedron/Plugins/Classification/Surface_mesh_item_classification.cpp b/Polyhedron/demo/Polyhedron/Plugins/Classification/Surface_mesh_item_classification.cpp
index 39e9d5cbb68..6f4d47b0704 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/Classification/Surface_mesh_item_classification.cpp
+++ b/Polyhedron/demo/Polyhedron/Plugins/Classification/Surface_mesh_item_classification.cpp
@@ -293,9 +293,9 @@ void Surface_mesh_item_classification::train (int classifier, const QMultipleInp
     if (m_ethz != NULL)
       delete m_ethz;
     m_ethz = new ETHZ_random_forest (m_labels, m_features);
-    m_ethz->train(training, true,
-                  dialog.get<QSpinBox>("num_trees")->value(),
-                  dialog.get<QSpinBox>("max_depth")->value());
+    m_ethz->train<Concurrency_tag>(training, true,
+                                   dialog.get<QSpinBox>("num_trees")->value(),
+                                   dialog.get<QSpinBox>("max_depth")->value());
     CGAL::Classification::classify<Concurrency_tag> (m_mesh->polyhedron()->faces(),
                                                      m_labels, *m_ethz,
                                                      indices, m_label_probabilities);