diff --git a/src/libslic3r/calib.hpp b/src/libslic3r/calib.hpp
index 3fff3621d2..45562a2bd4 100644
--- a/src/libslic3r/calib.hpp
+++ b/src/libslic3r/calib.hpp
@@ -257,7 +257,6 @@ private:
     const double m_speed_first_layer {30};
     const double m_speed_perimeter {100};
     
-    const double m_prime_zone_buffer {10};
     const int m_wall_count {3};
     const double m_wall_side_length {30.0};
     const int m_corner_angle {90};