diff --git a/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp b/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp
index 41361eaa94..588ddd6229 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp
@@ -205,7 +205,6 @@ void GLGizmoFdmSupports::update_from_model_object()
         if (mv->is_model_part())
             ++num_of_volumes;
     m_selected_facets.resize(num_of_volumes);
-    m_neighbors.resize(num_of_volumes);
 
     m_ivas.clear();
     m_ivas.resize(num_of_volumes);
@@ -235,17 +234,6 @@ void GLGizmoFdmSupports::update_from_model_object()
         }
         update_vertex_buffers(mesh, volume_id, FacetSupportType::ENFORCER);
         update_vertex_buffers(mesh, volume_id, FacetSupportType::BLOCKER);
-
-        m_neighbors[volume_id].resize(3 * mesh->its.indices.size());
-
-        // Prepare vector of vertex_index - facet_index pairs to quickly find adjacent facets
-        for (size_t i=0; i<mesh->its.indices.size(); ++i) {
-            const stl_triangle_vertex_indices& ind  = mesh->its.indices[i];
-            m_neighbors[volume_id][3*i] = std::make_pair(ind(0), i);
-            m_neighbors[volume_id][3*i+1] = std::make_pair(ind(1), i);
-            m_neighbors[volume_id][3*i+2] = std::make_pair(ind(2), i);
-        }
-        std::sort(m_neighbors[volume_id].begin(), m_neighbors[volume_id].end());
     }
 }
 
@@ -267,11 +255,6 @@ bool GLGizmoFdmSupports::is_mesh_point_clipped(const Vec3d& point) const
 }
 
 
-bool operator<(const GLGizmoFdmSupports::NeighborData& a, const GLGizmoFdmSupports::NeighborData& b) {
-    return a.first < b.first;
-}
-
-
 // Following function is called from GLCanvas3D to inform the gizmo about a mouse/keyboard event.
 // The gizmo has an opportunity to react - if it does, it should return true so that the Canvas3D is
 // aware that the event was reacted to and stops trying to make different sense of it. If the gizmo
@@ -404,8 +387,6 @@ bool GLGizmoFdmSupports::gizmo_event(SLAGizmoEventType action, const Vec2d& mous
 
             const std::pair<Vec3f, size_t>& hit_and_facet = { closest_hit, closest_facet };
 
-            const std::vector<NeighborData>& neighbors = m_neighbors[mesh_id];
-
             // Calculate direction from camera to the hit (in mesh coords):
             Vec3f dir = ((trafo_matrix.inverse() * camera.get_position()).cast<float>() - hit_and_facet.first).normalized();
 
@@ -419,28 +400,22 @@ bool GLGizmoFdmSupports::gizmo_event(SLAGizmoEventType action, const Vec2d& mous
             auto faces_camera = [&dir, &mesh](const size_t& facet) -> bool {
                 return (mesh->stl.facet_start[facet].normal.dot(dir) > 0.);
             };
-            // Now start with the facet the pointer points to and check all adjacent facets. neighbors vector stores
-            // pairs of vertex_idx - facet_idx and is sorted with respect to the former. Neighboring facet index can be
-            // quickly found by finding a vertex in the list and read the respective facet ids.
+            // Now start with the facet the pointer points to and check all adjacent facets.
             std::vector<size_t> facets_to_select{hit_and_facet.second};
-            NeighborData vertex = std::make_pair(0, 0);
             std::vector<bool> visited(m_selected_facets[mesh_id].size(), false); // keep track of facets we already processed
             size_t facet_idx = 0; // index into facets_to_select
-            auto it = neighbors.end();
             while (facet_idx < facets_to_select.size()) {
                 size_t facet = facets_to_select[facet_idx];
                 if (! visited[facet]) {
-                    // check all three vertices and in case they're close enough, find the remaining facets
-                    // and add them to the list to be proccessed later
+                    // check all three vertices and in case they're close enough,
+                    // add neighboring facets to be proccessed later
                     for (size_t i=0; i<3; ++i) {
-                        vertex.first = mesh->its.indices[facet](i); // vertex index
-                        float dist = squared_distance_from_line(mesh->its.vertices[vertex.first]);
+                        float dist = squared_distance_from_line(
+                                    mesh->its.vertices[mesh->its.indices[facet](i)]);
                         if (dist < limit) {
-                            it = std::lower_bound(neighbors.begin(), neighbors.end(), vertex);
-                            while (it != neighbors.end() && it->first == vertex.first) {
-                                if (it->second != facet && faces_camera(it->second))
-                                    facets_to_select.push_back(it->second);
-                                ++it;
+                            for (int n=0; n<3; ++n) {
+                                if (faces_camera(mesh->stl.neighbors_start[facet].neighbor[n]))
+                                    facets_to_select.push_back(mesh->stl.neighbors_start[facet].neighbor[n]);
                             }
                         }
                     }
@@ -809,7 +784,6 @@ void GLGizmoFdmSupports::on_set_state()
         }
         m_old_mo_id = -1;
         m_ivas.clear();
-        m_neighbors.clear();
         m_selected_facets.clear();
     }
     m_old_state = m_state;
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.hpp b/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.hpp
index e7f3a2063d..f481afc377 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.hpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.hpp
@@ -49,7 +49,6 @@ public:
     ~GLGizmoFdmSupports() override;
     void set_fdm_support_data(ModelObject* model_object, const Selection& selection);
     bool gizmo_event(SLAGizmoEventType action, const Vec2d& mouse_position, bool shift_down, bool alt_down, bool control_down);
-    using NeighborData = std::pair<size_t, size_t>;
 
 
 private:
@@ -86,8 +85,6 @@ private:
     Button m_button_down = Button::None;
     EState m_old_state = Off; // to be able to see that the gizmo has just been closed (see on_set_state)
 
-    std::vector<std::vector<NeighborData>> m_neighbors; // pairs of vertex_index - facet_index for each mesh
-
 protected:
     void on_set_state() override;
     void on_start_dragging() override;