diff --git a/library/rsa.c b/library/rsa.c
index d39a09b..4929275 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -269,9 +269,9 @@
     {
         /* We already have blinding values, just update them by squaring */
         MPI_CHK( mpi_mul_mpi( &ctx->Vi, &ctx->Vi, &ctx->Vi ) );
-        MPI_CHK( mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->P ) );
+        MPI_CHK( mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->N ) );
         MPI_CHK( mpi_mul_mpi( &ctx->Vf, &ctx->Vf, &ctx->Vf ) );
-        MPI_CHK( mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->P ) );
+        MPI_CHK( mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->N ) );
 
         return( 0 );
     }