diff --git a/Makefile b/Makefile
index ff04f1e1e..448bd3b5a 100644
--- a/Makefile
+++ b/Makefile
@@ -167,6 +167,7 @@ EXPORT_VM = $(patsubst %.cpp, %.o, $(wildcard Machines/export-*.cpp))
 
 export-trunc.x: Machines/export-ring.o
 export-sort.x: Machines/export-ring.o
+export-msort.x: Machines/export-ring.o
 export-a2b.x: GC/AtlasSecret.o Machines/SPDZ.o Machines/SPDZ2^64+64.o $(GC_SEMI) $(TINIER) $(EXPORT_VM) GC/Rep4Secret.o GC/Rep4Prep.o $(FHEOFFLINE)
 export-b2a.x: Machines/export-ring.o
 
diff --git a/Processor/FunctionArgument.cpp b/Processor/FunctionArgument.cpp
index d1e1f5685..0a3b173b1 100644
--- a/Processor/FunctionArgument.cpp
+++ b/Processor/FunctionArgument.cpp
@@ -42,3 +42,8 @@ void FunctionArgument::check_type(const string& type_string)
                 "return type mismatch: " + get_type_string() + "/"
                         + type_string);
 }
+
+bool FunctionArgument::has_reg_type(const char* reg_type)
+{
+    return this->reg_type == string(reg_type);
+}
diff --git a/Processor/FunctionArgument.h b/Processor/FunctionArgument.h
index eaf35c17c..65fa2d508 100644
--- a/Processor/FunctionArgument.h
+++ b/Processor/FunctionArgument.h
@@ -73,6 +73,15 @@ class FunctionArgument
         }
     }
 
+    /**
+     * Argument with integer array.
+     */
+    FunctionArgument(vector<long>& values) :
+            data(values.data()), size(values.size()), n_bits(0),
+            reg_type("ci"), memory(false)
+    {
+    }
+
     size_t get_size()
     {
         return size;
@@ -116,6 +125,8 @@ class FunctionArgument
         return memory;
     }
 
+    bool has_reg_type(const char* reg_type);
+
     template<class T>
     T& get_value(size_t index)
     {
diff --git a/Processor/Machine.hpp b/Processor/Machine.hpp
index 2b31b950f..5c72ffc3d 100644
--- a/Processor/Machine.hpp
+++ b/Processor/Machine.hpp
@@ -443,7 +443,7 @@ void Machine<sint, sgf2n>::run_function(const string& name,
                   arguments[i].get_value<vector<typename sint::bit_type>>(j).at(
                       k);
           }
-        else
+        else if (arguments[i].has_reg_type("s"))
           {
             auto& value = arguments[i].get_value<sint>(j);
             if (arguments[i].get_memory())
@@ -451,11 +451,17 @@ void Machine<sint, sgf2n>::run_function(const string& name,
             else
               processor.Procp.get_S()[arg_regs.at(i) + j] = value;
           }
+        else
+          {
+            assert(arguments[i].has_reg_type("ci"));
+            processor.write_Ci(arg_regs.at(i) + j, arguments[i].get_value<long>(j));
+          }
       }
 
   run_tape(0, tape_number, 0, N.num_players());
   join_tape(0);
 
+  assert(result.has_reg_type("s"));
   for (size_t j = 0; j < result.get_size(); j++)
     result.get_value<sint>(j) = processor.Procp.get_S()[return_reg + j];
 
diff --git a/Programs/Source/export-msort.py b/Programs/Source/export-msort.py
new file mode 100644
index 000000000..659824439
--- /dev/null
+++ b/Programs/Source/export-msort.py
@@ -0,0 +1,8 @@
+@export
+def sort(x, key_indices):
+    print_ln('x=%s', x.reveal())
+    print_ln('key_indices=%s', key_indices)
+    res = x.sort(key_indices=key_indices)
+    print_ln('res=%s', x.reveal())
+
+sort(sint.Matrix(500, 2), regint(0, size=1))
diff --git a/Utils/export-msort.cpp b/Utils/export-msort.cpp
new file mode 100644
index 000000000..7a1c45cd5
--- /dev/null
+++ b/Utils/export-msort.cpp
@@ -0,0 +1,59 @@
+/*
+ * export-sort.cpp
+ *
+ */
+
+#include "Machines/minimal.hpp"
+
+int main(int argc, const char** argv)
+{
+    assert(argc > 1);
+    int my_number = atoi(argv[1]);
+    int port_base = 9999;
+    Names N(my_number, 3, "localhost", port_base);
+
+    typedef Rep3Share2<64> share_type;
+    Machine<share_type> machine(N);
+
+    int n = 1000;
+
+    vector<share_type> inputs;
+    for (int i = 0; i < n; i++)
+    {
+        int j = (i % 2) ? i : (n - i);
+        inputs.push_back(share_type::constant(j, my_number));
+    }
+
+    vector<long> key_indices = {1};
+
+    vector<FunctionArgument> args = {{inputs, true}, key_indices};
+    FunctionArgument res;
+
+    machine.run_function("sort", res, args);
+
+    Opener<share_type> MC(machine.get_player(), machine.get_sint_mac_key());
+    MC.init_open();
+    for (auto& x : inputs)
+        MC.prepare_open(x);
+    MC.exchange();
+
+    if (my_number == 0)
+    {
+        cout << "res: ";
+        for (int i = 0; i < 10; i++)
+            cout << MC.finalize_open() << " ";
+        cout << endl;
+    }
+    else
+    {
+        for (int i = 0; i < n; i++)
+        {
+            auto x = MC.finalize_open();
+            if (not i % 2 and x != i + 2)
+            {
+                cerr << "error at " << i << ": " << x << endl;
+                exit(1);
+            }
+        }
+    }
+}