diff --git a/install b/install
index 5002ed22afdcfc9ce9ca589e81c3757af8a9a4ae..4b89a49aa185162a46d280056b4cedf8b10c64b2 100755
--- a/install
+++ b/install
@@ -225,7 +225,7 @@ fi
 
 ### MPI compilers must be in your PATH folder
 
-set_mpi $i_dir
+set_mpi $i_dir $ncore
 
 ### METIS and ParMETIS must be installed independently from sistem wide installation
 
diff --git a/script/set_mpi b/script/set_mpi
index 0bc7d554939d106cbf8dd82dd42141f504985f8d..4561e07a864df5ff4b320fb3c7633c6557aae2d5 100755
--- a/script/set_mpi
+++ b/script/set_mpi
@@ -5,9 +5,9 @@ function set_mpi()
   if [ x"$MPI_valid" == x"yes" ]; then
         configure_options="$configure_options CXX=mpic++ "
   else
-        ./script/install_MPI.sh $i_dir $ncore
+        ./script/install_MPI.sh $1 $2
         MPI_installed=1
-        export PATH="$i_dir/MPI/bin:$PATH"
+        export PATH="$1/MPI/bin:$PATH"
         configure_options="$configure_options CXX=mpic++ "
   fi