diff --git a/src/libslic3r/PerimeterGenerator.cpp b/src/libslic3r/PerimeterGenerator.cpp
index 488f836cfc..1ad0c92f8a 100644
--- a/src/libslic3r/PerimeterGenerator.cpp
+++ b/src/libslic3r/PerimeterGenerator.cpp
@@ -899,7 +899,7 @@ void PerimeterGenerator::split_top_surfaces(const ExPolygons &orig_polygons, ExP
         offset_top_surface = 0;
     // don't takes into account too thin areas
     // skip if the exposed area is smaller than "min_width_top_surface"
-    double min_width_top_surface = std::max(double(ext_perimeter_spacing / 2 + 10), config->min_width_top_surface.get_abs_value(perimeter_width));
+    double min_width_top_surface = std::max(double(ext_perimeter_spacing / 2 + 10), scale_(config->min_width_top_surface.get_abs_value(unscale_(perimeter_width))));
 
     Polygons grown_upper_slices = offset(*this->upper_slices, min_width_top_surface);