diff --git a/CHANGES.mp.md b/CHANGES.mp.md
index bbe4dacc8..1a8d2345a 100644
--- a/CHANGES.mp.md
+++ b/CHANGES.mp.md
@@ -3,6 +3,8 @@ Summary of recent updates to the AMPL MP Library
 
 
 ## unreleased
+- Option tech:writemodel:index to choose the iteration
+	when solver model is exported.
 - SCIP (and any solver with linear objective
 	and non-linear constraints): improve reformulation
 	of QP objectives.
diff --git a/include/mp/backend-std.h b/include/mp/backend-std.h
index 094f93735..5174ce48d 100644
--- a/include/mp/backend-std.h
+++ b/include/mp/backend-std.h
@@ -173,7 +173,7 @@ class StdBackend :
       /// Redefine this if you want some extensions
       /// to be written after solving instead.
       /// This is for compatibility wiht ASL drivers
-      /// where 'writeprob' was used for native-format model
+      /// where 'writeprob' was used both for native-format model
       /// and solution output #218.
       virtual std::set<std::string> NativeResultExtensions() const
   { return {".sol", ".ilp", ".mst", ".hnt", ".bas", ".json"}; }
@@ -276,9 +276,11 @@ class StdBackend :
     auto get_sol = [this]() {
       return GetSolution();
     };
-    int i=0;
+    int i_solve=0;
     while (GetMM().PrepareSolveIteration(get_stt, get_sol)) {
-      // ExportModel({"/tmp/model" + std::to_string(++i) + ".lp"});
+      if (++i_solve==storedOptions_.writemodel_index_
+          && exportFileMode() > 0)
+        ExportModel(export_file_names());
       Solve();
     }
   }
@@ -808,6 +810,7 @@ class StdBackend :
 
     /// For write prob
     std::vector<std::string> export_files_;
+    int writemodel_index_ = 0;
     std::vector<std::string> just_export_files_;
     /// For write sol
     std::vector<std::string> export_sol_files_;
@@ -936,12 +939,22 @@ class StdBackend :
     }
 
     if (IMPL_HAS_STD_FEATURE(WRITE_PROBLEM)) {
-      AddListOption("tech:writemodel writeprob writemodel tech:exportfile",
+      AddListOption("tech:writemodel tech:writeprob writeprob writemodel tech:exportfile",
         "Specifies files where to export the model before "
         "solving (repeat the option for several files.) "
-        "File name extensions can be ``.lp[.7z]``, ``.mps``, etc.",
+        "File name extensions can be ``.lp[.7z]``, ``.mps``, etc."
+                    "\n"
+                    "To write a model during iterative solve (e.g., with obj:multi=2), "
+                    "use tech:writemodel:index.",
         storedOptions_.export_files_);
 
+      AddStoredOption("tech:writemodel:index tech:writeprob:index writeprobindex writemodelindex",
+                    "During iterative solve (e.g., with obj:multi=2), "
+                    "the iteration before which to write solver model. "
+                    "0 means before iteration is initialized; positive value - "
+                    "before solving that iteration. Default 0.",
+                    storedOptions_.writemodel_index_);
+
       AddListOption("tech:writemodelonly justwriteprob justwritemodel",
         "Specifies files where to export the model, no solving "
         "(option can be repeated.) "
diff --git a/include/mp/flat/constr_2_expr.h b/include/mp/flat/constr_2_expr.h
index 8c7b929de..bcccd2479 100644
--- a/include/mp/flat/constr_2_expr.h
+++ b/include/mp/flat/constr_2_expr.h
@@ -415,11 +415,15 @@ class Constraints2Expr {
     lt_out_vars.reserve(nvars);
     result.reserve(ltin.size() - nvars);
     int v=0;
+    double c=0.0;
     for (size_t i=0; i<ltin.size(); ++i) {
-      if (MPCD( IsProperVar(v = ltin.var(i)) )) {
-        lt_out_vars.add_term(ltin.coef(i), v);
-      } else
-        result.add_term(ltin.coef(i), v);
+      if ((c = ltin.coef(i))) {                       // non-0
+        if (MPCD( IsProperVar(v = ltin.var(i)) )) {
+          lt_out_vars.add_term(c, v);
+        } else {
+          result.add_term(c, v);
+        }
+      }
     }
     return result;
   }
diff --git a/include/mp/flat/converter_multiobj.h b/include/mp/flat/converter_multiobj.h
index 3c4904ee2..188f53b83 100644
--- a/include/mp/flat/converter_multiobj.h
+++ b/include/mp/flat/converter_multiobj.h
@@ -137,7 +137,7 @@ class MOManager {
       const auto& i0_vec = pr_level.second;
       obj_new_.push_back(obj_orig.at(i0_vec.front()));
       obj_new_.back().set_sense(obj_orig.front().obj_sense());      // "Legacy" obj:multi:weight
-      obj_new_.back().set_sense_true(obj_orig.front().obj_sense());
+      obj_new_.back().set_sense_true(obj_orig.front().obj_sense_true());
       obj_new_.back().GetLinTerms() *= objwgt.at(i0_vec.front());   // Use weight
       obj_new_.back().GetQPTerms() *= objwgt.at(i0_vec.front());
       obj_new_tola_.push_back(objtola.at(i0_vec.front()));
diff --git a/solvers/scipmp/scipmpbackend.cc b/solvers/scipmp/scipmpbackend.cc
index c5054f40b..7375866bd 100644
--- a/solvers/scipmp/scipmpbackend.cc
+++ b/solvers/scipmp/scipmpbackend.cc
@@ -140,8 +140,6 @@ void ScipBackend::SetInterrupter(mp::Interrupter *inter) {
 }
 
 void ScipBackend::Solve() {
-  if (!storedOptions_.exportFile_.empty())
-    ExportModel(storedOptions_.exportFile_);
   if (!storedOptions_.paramRead_.empty())
     SCIP_CCALL( SCIPreadParams(getSCIP(), storedOptions_.paramRead_.c_str()) );
   if (!storedOptions_.logFile_.empty())
@@ -368,12 +366,6 @@ void ScipBackend::InitCustomOptions() {
     "0*/1/2/3/4/5: Whether to write SCIP log lines (chatter) to stdout and to file (native output level of SCIP).",
     "display/verblevel", 0, 5);
 
-  AddStoredOption("tech:exportfile writeprob writemodel",
-    "Specifies the name of a file where to export the model before "
-    "solving it. This file name can have extension ``.lp``, ``.mps``, etc. "
-    "Default = \"\" (don't export the model).",
-    storedOptions_.exportFile_);
-
   AddStoredOption("tech:logfile logfile",
     "Log file name.",
     storedOptions_.logFile_);
@@ -963,6 +955,9 @@ void ScipBackend::AddMIPStart(ArrayRef<double> x0, ArrayRef<int> sparsity) {
   SCIP_CCALL( SCIPaddSolFree(getSCIP(), &solution, &keep) );
 }
 
+void ScipBackend::DoWriteProblem(const std::string& name) {
+  ExportModel(name);
+}
 
 } // namespace mp
 
diff --git a/solvers/scipmp/scipmpbackend.h b/solvers/scipmp/scipmpbackend.h
index 46b93d17c..e1bc9a601 100644
--- a/solvers/scipmp/scipmpbackend.h
+++ b/solvers/scipmp/scipmpbackend.h
@@ -81,6 +81,12 @@ class ScipBackend :
   void AddMIPStart(ArrayRef<double> x0,
 									 ArrayRef<int> sparsity) override;
 
+  /**
+  * EXPORT PROBLEM
+  **/
+  ALLOW_STD_FEATURE(WRITE_PROBLEM, true)
+  void DoWriteProblem(const std::string& name) override;
+
 
  /**
   * Get MIP Gap
@@ -157,7 +163,7 @@ class ScipBackend :
 private:
   /// These options are stored in the class
   struct Options {
-    std::string exportFile_, logFile_, paramRead_;
+    std::string logFile_, paramRead_;
     int concurrent_ = 0;
     int heuristics_ = 0;
     int cuts_ = 0;
diff --git a/test/end2end/cases/categorized/fast/multi_obj/modellist.json b/test/end2end/cases/categorized/fast/multi_obj/modellist.json
index b77ef0ab8..0ff8e2043 100644
--- a/test/end2end/cases/categorized/fast/multi_obj/modellist.json
+++ b/test/end2end/cases/categorized/fast/multi_obj/modellist.json
@@ -260,6 +260,20 @@
       "_sobj[2]": -17
     }
   },
+  {
+    "name" : "obj_abs_01 obj:multi=2 writeprobindex",
+    "tags" : ["linear", "integer", "multiobj"],
+    "options": {
+      "ANYSOLVER_options": "multiobj=2 writeprob=obj_abs_01.lp writeprobindex=2",
+      "scip_options": "multiobj=2 writeprob=obj_abs_01.cip writeprobindex=2",
+      "gcg_options": "multiobj=2 writeprob=obj_abs_01.lp writeprobindex=2",
+      "mosek_options": "multiobj=2 writeprob=obj_abs_01.jtask writeprobindex=2"
+    },
+    "values": {
+      "_sobj[1]": 13,
+      "_sobj[2]": -17
+    }
+  },
   {
     "name" : "obj_abs_02",
     "tags" : ["linear", "integer", "multiobj"],