diff --git a/src/libslic3r/GCode/WipeTower.cpp b/src/libslic3r/GCode/WipeTower.cpp
index 62a964a20..79da52239 100644
--- a/src/libslic3r/GCode/WipeTower.cpp
+++ b/src/libslic3r/GCode/WipeTower.cpp
@@ -1083,7 +1083,7 @@ WipeTower::ToolChangeResult WipeTower::finish_layer(bool extrude_perimeter, bool
 	// Slow down on the 1st layer.
     bool first_layer = is_first_layer();
     // BBS: speed up perimeter speed to 90mm/s for non-first layer
-    float feedrate = first_layer ? std::min(m_first_layer_speed * 60.f, 5400.f) : std::min(m_filpar[m_current_tool].max_e_speed, 5400.f);
+    float           feedrate   = first_layer ? std::min(m_first_layer_speed * 60.f, 5400.f) : std::min(60.0f * m_filpar[m_current_tool].max_e_speed / m_extrusion_flow, 5400.f);
     float fill_box_y = m_layer_info->toolchanges_depth() + m_perimeter_width;
     box_coordinates fill_box(Vec2f(m_perimeter_width, fill_box_y),
                              m_wipe_tower_width - 2 * m_perimeter_width, m_layer_info->depth - fill_box_y);
@@ -1550,7 +1550,7 @@ WipeTower::ToolChangeResult WipeTower::only_generate_out_wall()
     // Slow down on the 1st layer.
     bool first_layer = is_first_layer();
     // BBS: speed up perimeter speed to 90mm/s for non-first layer
-    float           feedrate   = first_layer ? std::min(m_first_layer_speed * 60.f, 5400.f) : std::min(m_filpar[m_current_tool].max_e_speed, 5400.f);
+    float           feedrate   = first_layer ? std::min(m_first_layer_speed * 60.f, 5400.f) : std::min(60.0f * m_filpar[m_current_tool].max_e_speed / m_extrusion_flow, 5400.f);
     float           fill_box_y = m_layer_info->toolchanges_depth() + m_perimeter_width;
     box_coordinates fill_box(Vec2f(m_perimeter_width, fill_box_y), m_wipe_tower_width - 2 * m_perimeter_width, m_layer_info->depth - fill_box_y);