diff --git a/xs/src/libslic3r/GCode.cpp b/xs/src/libslic3r/GCode.cpp
index 93f324a1d..f46d35657 100644
--- a/xs/src/libslic3r/GCode.cpp
+++ b/xs/src/libslic3r/GCode.cpp
@@ -480,6 +480,7 @@ bool GCode::_do_export(Print &print, FILE *file)
     {
         const PrintObject *first_object = print.objects.front();
         const double       layer_height = first_object->config.layer_height.value;
+        const double       first_layer_height = first_object->config.first_layer_height.get_abs_value(layer_height);
         for (size_t region_id = 0; region_id < print.regions.size(); ++ region_id) {
             auto region = print.regions[region_id];
             fprintf(file, "; external perimeters extrusion width = %.2fmm\n", region->flow(frExternalPerimeter, layer_height, false, false, -1., *first_object).width);
@@ -490,7 +491,7 @@ bool GCode::_do_export(Print &print, FILE *file)
             if (print.has_support_material())
                 fprintf(file, "; support material extrusion width = %.2fmm\n", support_material_flow(first_object).width);
             if (print.config.first_layer_extrusion_width.value > 0)
-                fprintf(file, "; first layer extrusion width = %.2fmm\n",   region->flow(frPerimeter, layer_height, false, true, -1., *first_object).width);
+                fprintf(file, "; first layer extrusion width = %.2fmm\n",   region->flow(frPerimeter, first_layer_height, false, true, -1., *first_object).width);
             fprintf(file, "\n");
         }
     }