diff --git a/src/libslic3r/GCode/WipeTower.cpp b/src/libslic3r/GCode/WipeTower.cpp
index 7908f64f0..40c3698d2 100644
--- a/src/libslic3r/GCode/WipeTower.cpp
+++ b/src/libslic3r/GCode/WipeTower.cpp
@@ -2535,7 +2535,7 @@ void WipeTower::plan_toolchange(float z_par, float layer_height_par, unsigned in
     if (!m_filament_map.empty() && m_filament_map[old_tool] != m_filament_map[new_tool]) {
         double e_flow                   = nozzle_change_extrusion_flow(layer_height_par);
         double length                   = m_filaments_change_length[old_tool] / e_flow;
-        int    nozzle_change_line_count = length / (m_wipe_tower_width - 2*m_nozzle_change_perimeter_width) + 1;
+        int    nozzle_change_line_count = std::ceil(length / (m_wipe_tower_width - 2*m_nozzle_change_perimeter_width));
         if (m_need_reverse_travel)
             nozzle_change_depth = m_tpu_fixed_spacing * nozzle_change_line_count * m_nozzle_change_perimeter_width;
         else
@@ -2925,6 +2925,7 @@ WipeTower::NozzleChangeResult WipeTower::nozzle_change_new(int old_filament_id,
                 break;
             }
     }
+    if (nozzle_change_line_count <= 0) return m_nozzle_change_result;
     auto format_nozzle_change_line = [](bool start, int old_filament_id, int new_filament_id) -> std::string {
         char        buff[64];
         std::string tag = start ? GCodeProcessor::reserved_tag(GCodeProcessor::ETags::NozzleChangeStart) : GCodeProcessor::reserved_tag(GCodeProcessor::ETags::NozzleChangeEnd);
@@ -3752,7 +3753,7 @@ void WipeTower::plan_tower_new()
                 if (!m_filament_map.empty() && m_filament_map[toolchange.old_tool] != m_filament_map[toolchange.new_tool]) {
                     double e_flow                   = nozzle_change_extrusion_flow(m_plan[idx].height);
                     double length                   = m_filaments_change_length[toolchange.old_tool] / e_flow;
-                    int    nozzle_change_line_count = length / (m_wipe_tower_width - 2*m_nozzle_change_perimeter_width) + 1;
+                    int    nozzle_change_line_count = std::ceil(length / (m_wipe_tower_width - 2*m_nozzle_change_perimeter_width));
                     if (m_need_reverse_travel)
                         nozzle_change_depth = m_tpu_fixed_spacing * nozzle_change_line_count * m_nozzle_change_perimeter_width;
                     else