diff --git a/src/libslic3r/calib.hpp b/src/libslic3r/calib.hpp
index b26a000790..19b19cf347 100644
--- a/src/libslic3r/calib.hpp
+++ b/src/libslic3r/calib.hpp
@@ -266,8 +266,18 @@ public:
 protected:
     double speed_first_layer() const { return m_config.option<ConfigOptionFloat>("initial_layer_speed")->value; };
     double speed_perimeter() const { return m_config.option<ConfigOptionFloat>("outer_wall_speed")->value; };
-    double line_width_first_layer() const { return m_config.get_abs_value("initial_layer_line_width"); };
-    double line_width() const { return m_config.get_abs_value("line_width"); };
+    double line_width_first_layer() const
+    {
+        // TODO: FIXME: find out current filament/extruder?
+        const double nozzle_diameter = m_config.opt_float("nozzle_diameter", 0);
+        return m_config.get_abs_value("initial_layer_line_width", nozzle_diameter);
+    };
+    double line_width() const
+    {
+        // TODO: FIXME: find out current filament/extruder?
+        const double nozzle_diameter = m_config.opt_float("nozzle_diameter", 0);
+        return m_config.get_abs_value("line_width", nozzle_diameter);
+    };
     int    wall_count() const { return m_config.option<ConfigOptionInt>("wall_loops")->value; };
 
 private: