diff --git a/src/libslic3r/PerimeterGenerator.cpp b/src/libslic3r/PerimeterGenerator.cpp
index 7a495edab..7649fea9e 100644
--- a/src/libslic3r/PerimeterGenerator.cpp
+++ b/src/libslic3r/PerimeterGenerator.cpp
@@ -394,8 +394,8 @@ void PerimeterGenerator::process()
     for (const Surface &surface : this->slices->surfaces) {
         // detect how many perimeters must be generated for this island
         int        loop_number = this->config->wall_loops + surface.extra_perimeters - 1;  // 0-indexed loops
-        //BBS: force the topmost layer to be one wall
-        if (loop_number > 0 && this->upper_slices == nullptr)
+        //BBS: set the topmost layer to be one wall
+        if (loop_number > 0 && config->only_one_wall_top && this->upper_slices == nullptr)
             loop_number = 0;
 
         ExPolygons last        = union_ex(surface.expolygon.simplify_p(surface_simplify_resolution));