diff --git a/library/bignum_mod_raw.c b/library/bignum_mod_raw.c
index d3cd770..4d5fe81 100644
--- a/library/bignum_mod_raw.c
+++ b/library/bignum_mod_raw.c
@@ -82,9 +82,9 @@
     switch( m->ext_rep )
     {
         case MBEDTLS_MPI_MOD_EXT_REP_LE:
-            return mbedtls_mpi_core_write_le( X, m->n, buf, buflen );
+            return( mbedtls_mpi_core_write_le( X, m->n, buf, buflen ) );
         case MBEDTLS_MPI_MOD_EXT_REP_BE:
-            return mbedtls_mpi_core_write_be( X, m->n, buf, buflen );
+            return( mbedtls_mpi_core_write_be( X, m->n, buf, buflen ) );
         default:
             return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
     }