diff --git a/DynamicModel.cc b/DynamicModel.cc
index ebf6b9b0..f3c90c25 100644
--- a/DynamicModel.cc
+++ b/DynamicModel.cc
@@ -800,7 +800,7 @@ DynamicModel::writeModelEquationsCode(string &file_name, const string &bin_basen
   code_file.open(main_name.c_str(), ios::out | ios::binary | ios::ate);
   if (!code_file.is_open())
     {
-      cout << "Error : Can't open file \"" << main_name << "\" for writing\n";
+      cerr << "Error : Can't open file \"" << main_name << "\" for writing" << endl;
       exit(EXIT_FAILURE);
     }
 
@@ -1076,7 +1076,7 @@ DynamicModel::writeModelEquationsCode_Block(string &file_name, const string &bin
   code_file.open(main_name.c_str(), ios::out | ios::binary | ios::ate);
   if (!code_file.is_open())
     {
-      cout << "Error : Can't open file \"" << main_name << "\" for writing\n";
+      cerr << "Error : Can't open file \"" << main_name << "\" for writing" << endl;
       exit(EXIT_FAILURE);
     }
   //Temporary variables declaration
@@ -1768,7 +1768,7 @@ DynamicModel::Write_Inf_To_Bin_File_Block(const string &dynamic_basename, const
     SaveCode.open((bin_basename + "_dynamic.bin").c_str(), ios::out | ios::binary);
   if (!SaveCode.is_open())
     {
-      cout << "Error : Can't open file \"" << bin_basename << "_dynamic.bin\" for writing\n";
+      cerr << "Error : Can't open file \"" << bin_basename << "_dynamic.bin\" for writing" << endl;
       exit(EXIT_FAILURE);
     }
   u_count_int = 0;
diff --git a/ModelTree.cc b/ModelTree.cc
index 1faac8ff..f295423e 100644
--- a/ModelTree.cc
+++ b/ModelTree.cc
@@ -1594,7 +1594,7 @@ ModelTree::Write_Inf_To_Bin_File(const string &basename,
     SaveCode.open(bin_basename.c_str(), ios::out | ios::binary);
   if (!SaveCode.is_open())
     {
-      cout << "Error : Can't open file \"" << bin_basename << "\" for writing\n";
+      cerr << "Error : Can't open file \"" << bin_basename << "\" for writing" << endl;
       exit(EXIT_FAILURE);
     }
   u_count_int = 0;
diff --git a/StaticModel.cc b/StaticModel.cc
index 2cdb2f0a..1d176027 100644
--- a/StaticModel.cc
+++ b/StaticModel.cc
@@ -412,7 +412,7 @@ StaticModel::writeModelEquationsCode(const string file_name, const string bin_ba
   code_file.open(main_name.c_str(), ios::out | ios::binary | ios::ate);
   if (!code_file.is_open())
     {
-      cout << "Error : Can't open file \"" << main_name << "\" for writing\n";
+      cerr << "Error : Can't open file \"" << main_name << "\" for writing" << endl;
       exit(EXIT_FAILURE);
     }
   int count_u;
@@ -596,7 +596,7 @@ StaticModel::writeModelEquationsCode_Block(const string file_name, const string
   code_file.open(main_name.c_str(), ios::out | ios::binary | ios::ate);
   if (!code_file.is_open())
     {
-      cout << "Error : Can't open file \"" << main_name << "\" for writing\n";
+      cerr << "Error : Can't open file \"" << main_name << "\" for writing" << endl;
       exit(EXIT_FAILURE);
     }
   //Temporary variables declaration
@@ -990,7 +990,7 @@ StaticModel::Write_Inf_To_Bin_File_Block(const string &static_basename, const st
     SaveCode.open((bin_basename + "_static.bin").c_str(), ios::out | ios::binary);
   if (!SaveCode.is_open())
     {
-      cout << "Error : Can't open file \"" << bin_basename << "_static.bin\" for writing\n";
+      cerr << "Error : Can't open file \"" << bin_basename << "_static.bin\" for writing" << endl;
       exit(EXIT_FAILURE);
     }
   u_count_int = 0;