diff --git a/src/db/db/dbInstances.cc b/src/db/db/dbInstances.cc
index 4d4c3c76e..4f1a8ca54 100644
--- a/src/db/db/dbInstances.cc
+++ b/src/db/db/dbInstances.cc
@@ -539,11 +539,6 @@ template class instance_iterator<OverlappingInstanceIteratorTraits>;
 // -------------------------------------------------------------------------------------
 //  NormalInstanceIteratorTraits implementation
 
-//  TODO: this class could use standard iterators instead of flat
-//  box tree ones. This potentially saves a sorting step when
-//  no box trees are needed and order will remain more stable in
-//  that case.
-
 NormalInstanceIteratorTraits::NormalInstanceIteratorTraits ()
   : mp_insts (0)
 { }
diff --git a/src/db/unit_tests/dbCellTests.cc b/src/db/unit_tests/dbCellTests.cc
index 5715d1053..0cffd31e6 100644
--- a/src/db/unit_tests/dbCellTests.cc
+++ b/src/db/unit_tests/dbCellTests.cc
@@ -998,6 +998,10 @@ TEST(6)
   //  Note: iterating and replace does not work in non-editable mode
   if (db::default_editable_mode ()) {
 
+    std::vector<db::Instance> insts;
+    for (db::Cell::const_iterator i = cc.begin (); ! i.at_end (); ++i) {
+      insts.push_back (*i);
+    }
     for (db::Cell::const_iterator i = cc.begin (); ! i.at_end (); ++i) {
       cc.replace_prop_id (*i, i->prop_id () + 1);
     }