diff --git a/lib/Slic3r/Layer/Region.pm b/lib/Slic3r/Layer/Region.pm
index 3e3854400..34da08e21 100644
--- a/lib/Slic3r/Layer/Region.pm
+++ b/lib/Slic3r/Layer/Region.pm
@@ -233,7 +233,7 @@ sub make_perimeters {
         
         # use a nearest neighbor search to order these children
         # TODO: supply second argument to chained_path() too?
-        my $sorted_collection = $collection->chained_path(0);
+        my $sorted_collection = $collection->chained_path_indices(0);
         my @orig_indices = @{$sorted_collection->orig_indices};
         
         my @loops = ();
diff --git a/xs/src/ExtrusionEntityCollection.cpp b/xs/src/ExtrusionEntityCollection.cpp
index 9e5fb83a7..f4d78b404 100644
--- a/xs/src/ExtrusionEntityCollection.cpp
+++ b/xs/src/ExtrusionEntityCollection.cpp
@@ -1,4 +1,5 @@
 #include "ExtrusionEntityCollection.hpp"
+#include <map>
 
 namespace Slic3r {
 
@@ -34,25 +35,30 @@ ExtrusionEntityCollection::last_point() const
 }
 
 ExtrusionEntityCollection*
-ExtrusionEntityCollection::chained_path(bool no_reverse) const
+ExtrusionEntityCollection::chained_path(bool no_reverse, std::vector<size_t>* orig_indices) const
 {
     if (this->entities.empty()) {
         return new ExtrusionEntityCollection ();
     }
-    return this->chained_path_from(this->entities.front()->first_point(), no_reverse);
+    return this->chained_path_from(this->entities.front()->first_point(), no_reverse, orig_indices);
 }
 
 ExtrusionEntityCollection*
-ExtrusionEntityCollection::chained_path_from(Point* start_near, bool no_reverse) const
+ExtrusionEntityCollection::chained_path_from(Point* start_near, bool no_reverse, std::vector<size_t>* orig_indices) const
 {
     if (this->no_sort) return this->clone();
     ExtrusionEntityCollection* retval = new ExtrusionEntityCollection;
     retval->entities.reserve(this->entities.size());
     retval->orig_indices.reserve(this->entities.size());
     
+    // if we're asked to return the original indices, build a map
+    std::map<ExtrusionEntity*,size_t> indices_map;
+    
     ExtrusionEntitiesPtr my_paths;
     for (ExtrusionEntitiesPtr::const_iterator it = this->entities.begin(); it != this->entities.end(); ++it) {
-        my_paths.push_back((*it)->clone());
+        ExtrusionEntity* entity = (*it)->clone();
+        my_paths.push_back(entity);
+        if (orig_indices != NULL) indices_map[entity] = it - this->entities.begin();
     }
     
     Points endpoints;
@@ -69,11 +75,12 @@ ExtrusionEntityCollection::chained_path_from(Point* start_near, bool no_reverse)
         // find nearest point
         int start_index = start_near->nearest_point_index(endpoints);
         int path_index = start_index/2;
+        ExtrusionEntity* entity = my_paths.at(path_index);
         if (start_index % 2 && !no_reverse) {
-            my_paths.at(path_index)->reverse();
+            entity->reverse();
         }
         retval->entities.push_back(my_paths.at(path_index));
-        retval->orig_indices.push_back(path_index);
+        if (orig_indices != NULL) orig_indices->push_back(indices_map[entity]);
         my_paths.erase(my_paths.begin() + path_index);
         endpoints.erase(endpoints.begin() + 2*path_index, endpoints.begin() + 2*path_index + 2);
         start_near = retval->entities.back()->last_point();
diff --git a/xs/src/ExtrusionEntityCollection.hpp b/xs/src/ExtrusionEntityCollection.hpp
index f4505183c..591546b36 100644
--- a/xs/src/ExtrusionEntityCollection.hpp
+++ b/xs/src/ExtrusionEntityCollection.hpp
@@ -11,11 +11,11 @@ class ExtrusionEntityCollection : public ExtrusionEntity
     public:
     ExtrusionEntityCollection* clone() const;
     ExtrusionEntitiesPtr entities;
-    std::vector<int> orig_indices;
+    std::vector<size_t> orig_indices;  // handy for XS
     bool no_sort;
     ExtrusionEntityCollection(): no_sort(false) {};
-    ExtrusionEntityCollection* chained_path(bool no_reverse) const;
-    ExtrusionEntityCollection* chained_path_from(Point* start_near, bool no_reverse) const;
+    ExtrusionEntityCollection* chained_path(bool no_reverse, std::vector<size_t>* orig_indices = NULL) const;
+    ExtrusionEntityCollection* chained_path_from(Point* start_near, bool no_reverse, std::vector<size_t>* orig_indices = NULL) const;
     void reverse();
     Point* first_point() const;
     Point* last_point() const;
diff --git a/xs/xsp/ExtrusionEntityCollection.xsp b/xs/xsp/ExtrusionEntityCollection.xsp
index 11c0d6168..f2196c760 100644
--- a/xs/xsp/ExtrusionEntityCollection.xsp
+++ b/xs/xsp/ExtrusionEntityCollection.xsp
@@ -20,7 +20,7 @@
         %code{% const char* CLASS = "Slic3r::Point"; RETVAL = THIS->last_point(); %};
     int count()
         %code{% RETVAL = THIS->entities.size(); %};
-    std::vector<int> orig_indices()
+    std::vector<size_t> orig_indices()
         %code{% RETVAL = THIS->orig_indices; %};
 %{
 
@@ -79,5 +79,16 @@ ExtrusionEntityCollection::no_sort(...)
     OUTPUT:
         RETVAL
 
+ExtrusionEntityCollection*
+ExtrusionEntityCollection::chained_path_indices(bool no_reverse)
+    PREINIT:
+        const char* CLASS = "Slic3r::ExtrusionPath::Collection";
+    CODE:
+        std::vector<size_t> indices;
+        RETVAL = THIS->chained_path(no_reverse, &indices);
+        RETVAL->orig_indices = indices;
+    OUTPUT:
+        RETVAL
+
 %}
 };
diff --git a/xs/xsp/my.map b/xs/xsp/my.map
index 0b4645656..9fbe0b907 100644
--- a/xs/xsp/my.map
+++ b/xs/xsp/my.map
@@ -1,4 +1,5 @@
 std::vector<Points::size_type>  T_STD_VECTOR_INT
+std::vector<size_t>  T_STD_VECTOR_INT
 t_config_option_key T_STD_STRING
 
 BoundingBox*         O_OBJECT
diff --git a/xs/xsp/typemap.xspt b/xs/xsp/typemap.xspt
index fdb66492e..176b49878 100644
--- a/xs/xsp/typemap.xspt
+++ b/xs/xsp/typemap.xspt
@@ -2,6 +2,7 @@
 %typemap{std::string};
 %typemap{t_config_option_key};
 %typemap{std::vector<int>};
+%typemap{std::vector<size_t>};
 %typemap{std::vector<unsigned int>*};
 %typemap{std::vector<double>};
 %typemap{std::vector<double>*};