diff --git a/PoissonSolver/2D-mpi/src/solver.h b/PoissonSolver/2D-mpi/src/solver.h
index f42f2c4..76bc29e 100644
--- a/PoissonSolver/2D-mpi/src/solver.h
+++ b/PoissonSolver/2D-mpi/src/solver.h
@@ -15,7 +15,7 @@ typedef struct {
     int jmaxLocal;
     int rank;
     int size;
-
+    double rho;
     double *p, *rhs;
     double eps, omega;
     int itermax;