diff --git a/core/indigo-core/molecule/src/molfile_saver.cpp b/core/indigo-core/molecule/src/molfile_saver.cpp
index d12da6366e..85b278bfbb 100644
--- a/core/indigo-core/molecule/src/molfile_saver.cpp
+++ b/core/indigo-core/molecule/src/molfile_saver.cpp
@@ -19,6 +19,7 @@
 #include "molecule/molfile_saver.h"
 
 #include <ctime>
+#include <map>
 #include <sstream>
 
 #include "base_cpp/locale_guard.h"
@@ -2000,7 +2001,7 @@ void MolfileSaver::_writeAttachmentValues2000(Output& output, BaseMolecule& frag
     if (fragment.attachmentPointCount() == 0)
         return;
 
-    RedBlackMap<int, int> orders;
+    std::map<int, int> orders;
     int i;
 
     for (i = 1; i <= fragment.attachmentPointCount(); i++)
@@ -2010,10 +2011,11 @@ void MolfileSaver::_writeAttachmentValues2000(Output& output, BaseMolecule& frag
 
         while ((idx = fragment.getAttachmentPoint(i, j++)) != -1)
         {
-            int* val;
+            auto it = orders.find(_atom_mapping[idx]);
+            int* val = it != orders.end() ? &(it->second) : nullptr;
 
-            if ((val = orders.at2(_atom_mapping[idx])) == 0)
-                orders.insert(_atom_mapping[idx], 1 << (i - 1));
+            if (!val)
+                orders.emplace(_atom_mapping[idx], 1 << (i - 1));
             else
                 *val |= 1 << (i - 1);
         }
@@ -2021,8 +2023,8 @@ void MolfileSaver::_writeAttachmentValues2000(Output& output, BaseMolecule& frag
 
     output.printf("M  APO%3d", orders.size());
 
-    for (i = orders.begin(); i < orders.end(); i = orders.next(i))
-        output.printf(" %3d %3d", orders.key(i), orders.value(i));
+    for (auto it = orders.begin(); it != orders.end(); it++)
+        output.printf(" %3d %3d", it->first, it->second);
 
     output.writeCR();
 }