diff --git a/src/libslic3r/PrintObject.cpp b/src/libslic3r/PrintObject.cpp
index b76eaa4574..d9c76ba849 100644
--- a/src/libslic3r/PrintObject.cpp
+++ b/src/libslic3r/PrintObject.cpp
@@ -633,13 +633,9 @@ void PrintObject::generate_support_material()
     if (this->set_started(posSupportMaterial)) {
         this->clear_support_layers();
 
-        if ((this->has_support() && m_layers.size() > 1) || (this->has_raft() && ! m_layers.empty())) {
-            m_print->set_status(50, L("Generating support"));
-
-            this->_generate_support_material();
-            m_print->throw_if_canceled();
-        } else if(!m_print->get_no_check_flag()) {
+        if(!has_support() && !m_print->get_no_check_flag()) {
             // BBS: pop a warning if objects have significant amount of overhangs but support material is not enabled
+            // Note: we also need to pop warning if support is disabled and only raft is enabled
             m_print->set_status(50, L("Checking support necessity"));
             typedef std::chrono::high_resolution_clock clock_;
             typedef std::chrono::duration<double, std::ratio<1> > second_;
@@ -669,6 +665,12 @@ void PrintObject::generate_support_material()
 #endif
         }
 
+        if ((this->has_support() && m_layers.size() > 1) || (this->has_raft() && !m_layers.empty())) {
+            m_print->set_status(50, L("Generating support"));
+
+            this->_generate_support_material();
+            m_print->throw_if_canceled();
+        }
         this->set_done(posSupportMaterial);
     }
 }
diff --git a/src/libslic3r/Support/TreeSupport.cpp b/src/libslic3r/Support/TreeSupport.cpp
index fa8ee64367..66e2f57c5d 100644
--- a/src/libslic3r/Support/TreeSupport.cpp
+++ b/src/libslic3r/Support/TreeSupport.cpp
@@ -625,7 +625,7 @@ TreeSupport::TreeSupport(PrintObject& object, const SlicingParameters &slicing_p
 
 
 #define SUPPORT_SURFACES_OFFSET_PARAMETERS ClipperLib::jtSquare, 0.
-void TreeSupport::detect_overhangs(bool detect_first_sharp_tail_only)
+void TreeSupport::detect_overhangs(bool check_support_necessity/* = false*/)
 {
     // overhangs are already detected
     if (m_object->support_layer_count() >= m_object->layer_count())
@@ -636,8 +636,8 @@ void TreeSupport::detect_overhangs(bool detect_first_sharp_tail_only)
     // Clear and create Tree Support Layers
     m_object->clear_support_layers();
     m_object->clear_tree_support_preview_cache();
-    create_tree_support_layers(tree_support_enable);
-    if (!tree_support_enable)
+    create_tree_support_layers();
+    if (!tree_support_enable && !check_support_necessity)
         return;
 
     const PrintObjectConfig& config = m_object->config();
@@ -863,9 +863,11 @@ void TreeSupport::detect_overhangs(bool detect_first_sharp_tail_only)
     ); // end tbb::parallel_for
 
     BOOST_LOG_TRIVIAL(info) << "max_cantilever_dist=" << max_cantilever_dist;
+    if (check_support_necessity)
+        return;
 
     // check if the sharp tails should be extended higher
-    if (is_auto(stype) && g_config_support_sharp_tails && !detect_first_sharp_tail_only) {
+    if (is_auto(stype) && g_config_support_sharp_tails) {
         for (size_t layer_nr = 0; layer_nr < m_object->layer_count(); layer_nr++) {
             if (m_object->print()->canceled())
                 break;
@@ -1104,7 +1106,7 @@ void TreeSupport::detect_overhangs(bool detect_first_sharp_tail_only)
 
 // create support layers for raft and tree support
 // if support is disabled, only raft layers are created
-void TreeSupport::create_tree_support_layers(bool support_enabled)
+void TreeSupport::create_tree_support_layers()
 {
     int layer_id = 0;
     coordf_t raft_print_z = 0.f;
@@ -1121,9 +1123,6 @@ void TreeSupport::create_tree_support_layers(bool support_enabled)
         m_object->add_tree_support_layer(layer_id, m_slicing_params.base_raft_layer_height, raft_print_z, raft_slice_z);
     }
 
-    if (!support_enabled)
-        return;
-
     for (Layer *layer : m_object->layers()) {
         SupportLayer* ts_layer = m_object->add_tree_support_layer(layer_id++, layer->height, layer->print_z, layer->slice_z);
         if (ts_layer->id() > m_raft_layers) {
diff --git a/src/libslic3r/Support/TreeSupport.hpp b/src/libslic3r/Support/TreeSupport.hpp
index 8c4a12f43b..d5e4d0fe2f 100644
--- a/src/libslic3r/Support/TreeSupport.hpp
+++ b/src/libslic3r/Support/TreeSupport.hpp
@@ -375,7 +375,7 @@ public:
      */
     void generate();
 
-    void detect_overhangs(bool detect_first_sharp_tail_only=false);
+    void detect_overhangs(bool check_support_necessity = false);
 
 
     int  avg_node_per_layer = 0;
@@ -484,7 +484,7 @@ private:
      * If a node is already at that position in the layer, the nodes are merged.
      */
     void insert_dropped_node(std::vector<SupportNode*>& nodes_layer, SupportNode* node);
-    void create_tree_support_layers(bool support_enabled=true);
+    void create_tree_support_layers();
     void generate_toolpaths();
     // get unscaled radius of node
     coordf_t calc_branch_radius(coordf_t base_radius, size_t layers_to_top, size_t tip_layers, double diameter_angle_scale_factor);