diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index 8bc80cd..51956cd 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -4712,7 +4712,6 @@
     mbedtls_mpi_free( &grp->G.Y );
 
     /* N = 2^446 - 13818066809895115352007386748515426880336692474882178609894547503885 */
-    MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &grp->N, 0 ) );
     MBEDTLS_MPI_CHK( mbedtls_mpi_set_bit( &grp->N, 446, 1 ) );
     MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &Ns,
                         curve448_part_of_n, sizeof( curve448_part_of_n ) ) );
@@ -4738,6 +4737,8 @@
     ECP_VALIDATE_RET( grp != NULL );
     mbedtls_ecp_group_free( grp );
 
+    mbedtls_ecp_group_init( grp );
+
     grp->id = id;
 
     switch( id )