diff --git a/ortools/linear_solver/csharp/linear_solver.i b/ortools/linear_solver/csharp/linear_solver.i
index 23e425b840d..5c23e6253cb 100644
--- a/ortools/linear_solver/csharp/linear_solver.i
+++ b/ortools/linear_solver/csharp/linear_solver.i
@@ -206,6 +206,9 @@ CONVERT_VECTOR(operations_research::MPVariable, MPVariable)
   }
 }
 
+%unignore operations_research::MPSolver::WriteModelAsLpFormat;
+%unignore operations_research::MPSolver::WriteModelAsMpsFormat;
+
 // MPVariable: writer API.
 %unignore operations_research::MPVariable::SetInteger;
 %rename (SetLb) operations_research::MPVariable::SetLB;