diff --git a/src/libslic3r/Interlocking/InterlockingGenerator.cpp b/src/libslic3r/Interlocking/InterlockingGenerator.cpp
index 07c3059302e..1899c0d1af6 100644
--- a/src/libslic3r/Interlocking/InterlockingGenerator.cpp
+++ b/src/libslic3r/Interlocking/InterlockingGenerator.cpp
@@ -21,7 +21,7 @@ template<> struct hash<Slic3r::GridPoint3>
 
 namespace Slic3r {
 
-void PrintObject::generate_interlocking_structure()
+void InterlockingGenerator::generate_interlocking_structure(PrintObject* print_object)
 {
     const float    rotation           = Geometry::deg2rad(22.5); //(global_settings.get<AngleDegrees>("interlocking_orientation"));
     const coord_t  beam_layer_count   = 2;    // global_settings.get<int>("interlocking_beam_layer_count");
@@ -37,18 +37,18 @@ void PrintObject::generate_interlocking_structure()
     const coord_t cell_width = beam_width + beam_width;
     const Vec3crd cell_size(cell_width, cell_width, 2 * beam_layer_count);
 
-    for (size_t region_a_index = 0; region_a_index < num_printing_regions(); region_a_index++) {
-        const PrintRegion& region_a = printing_region(region_a_index);
+    for (size_t region_a_index = 0; region_a_index < print_object->num_printing_regions(); region_a_index++) {
+        const PrintRegion& region_a      = print_object->printing_region(region_a_index);
         const auto         extruder_nr_a = region_a.extruder(FlowRole::frExternalPerimeter);
 
-        for (size_t region_b_index = region_a_index + 1; region_b_index < num_printing_regions(); region_b_index++) {
-            const PrintRegion& region_b      = printing_region(region_b_index);
+        for (size_t region_b_index = region_a_index + 1; region_b_index < print_object->num_printing_regions(); region_b_index++) {
+            const PrintRegion& region_b      = print_object->printing_region(region_b_index);
             const auto         extruder_nr_b = region_b.extruder(FlowRole::frExternalPerimeter);
             if (extruder_nr_a == extruder_nr_b) {
                 continue;
             }
 
-            InterlockingGenerator gen(*this, region_a_index, region_b_index, beam_width, boundary_avoidance, rotation, cell_size, beam_layer_count,
+            InterlockingGenerator gen(*print_object, region_a_index, region_b_index, beam_width, boundary_avoidance, rotation, cell_size, beam_layer_count,
                                       interface_dilation, air_dilation, air_filtering);
             gen.generateInterlockingStructure();
         }
diff --git a/src/libslic3r/Interlocking/InterlockingGenerator.hpp b/src/libslic3r/Interlocking/InterlockingGenerator.hpp
index 7573775fc46..aca74010cd0 100644
--- a/src/libslic3r/Interlocking/InterlockingGenerator.hpp
+++ b/src/libslic3r/Interlocking/InterlockingGenerator.hpp
@@ -42,6 +42,12 @@ namespace Slic3r {
 class InterlockingGenerator
 {
 public:
+    /*!
+     * Generate an interlocking structure between each two adjacent meshes.
+     */
+    static void generate_interlocking_structure(PrintObject* print_object);
+
+private:
     /*!
      * Generate an interlocking structure between two meshes
      */
@@ -83,8 +89,6 @@ class InterlockingGenerator
         , air_dilation(air_dilation)
         , air_filtering(air_filtering)
     {}
-
-private:
     
     /*! Given two polygons, return the parts that border on air, and grow 'perpendicular' up to 'detect' distance.
      *
diff --git a/src/libslic3r/Print.hpp b/src/libslic3r/Print.hpp
index c6acc1e4933..bd7b867b99e 100644
--- a/src/libslic3r/Print.hpp
+++ b/src/libslic3r/Print.hpp
@@ -550,10 +550,6 @@ class PrintObject : public PrintObjectBaseWithState<Print, PrintObjectStep, posC
     size_t               m_id;
     void apply_conical_overhang();
 
-    // Generate an interlocking structure between each two adjacent meshes.
-    friend class InterlockingGenerator;
-    void generate_interlocking_structure();
-
  public:
     //BBS: When printing multi-material objects, this settings will make slicer to clip the overlapping object parts one by the other.
     //(2nd part will be clipped by the 1st, 3rd part will be clipped by the 1st and 2nd etc).
diff --git a/src/libslic3r/PrintObjectSlice.cpp b/src/libslic3r/PrintObjectSlice.cpp
index 1ac426336af..3131ffc9cf4 100644
--- a/src/libslic3r/PrintObjectSlice.cpp
+++ b/src/libslic3r/PrintObjectSlice.cpp
@@ -4,6 +4,7 @@
 #include "MultiMaterialSegmentation.hpp"
 #include "Print.hpp"
 #include "ClipperUtils.hpp"
+#include "Interlocking/InterlockingGenerator.hpp"
 //BBS
 #include "ShortestPath.hpp"
 
@@ -11,6 +12,7 @@
 
 #include <tbb/parallel_for.h>
 
+
 //! macro used to mark string used at localization, return same string
 #define L(s) Slic3r::I18N::translate(s)
 
@@ -1072,7 +1074,7 @@ void PrintObject::slice_volumes()
     this->apply_conical_overhang();
     m_print->throw_if_canceled();
 
-    this->generate_interlocking_structure();
+    InterlockingGenerator::generate_interlocking_structure(this);
     m_print->throw_if_canceled();
 
     BOOST_LOG_TRIVIAL(debug) << "Slicing volumes - make_slices in parallel - begin";