diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index b81d556dd..7a0f30c7d 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -503,6 +503,8 @@ static std::vector<Vec2d> get_path_of_change_filament(const Print& print)
                 config.set_key_value("travel_point_3_x", new ConfigOptionFloat(float(travel_point_3.x())));
                 config.set_key_value("travel_point_3_y", new ConfigOptionFloat(float(travel_point_3.y())));
 
+                config.set_key_value("flush_length", new ConfigOptionFloat(purge_length));
+
                 int flush_count = std::min(g_max_flush_count, (int)std::round(purge_volume / g_purge_volume_one_time));
                 float flush_unit = purge_length / flush_count;
                 int flush_idx = 0;
@@ -4927,6 +4929,8 @@ std::string GCode::set_extruder(unsigned int extruder_id, double print_z, bool b
     dyn_config.set_key_value("travel_point_3_x", new ConfigOptionFloat(float(travel_point_3.x())));
     dyn_config.set_key_value("travel_point_3_y", new ConfigOptionFloat(float(travel_point_3.y())));
 
+    dyn_config.set_key_value("flush_length", new ConfigOptionFloat(wipe_length));
+
     int flush_count = std::min(g_max_flush_count, (int)std::round(wipe_volume / g_purge_volume_one_time));
     float flush_unit = wipe_length / flush_count;
     int flush_idx = 0;