diff --git a/library/bignum_new.c b/library/bignum_new.c
index 976301d..b6a806e 100644
--- a/library/bignum_new.c
+++ b/library/bignum_new.c
@@ -413,10 +413,10 @@
                               unsigned char *buf,
                               size_t buflen )
 {
-    if( m->ext_rep & MBEDTLS_MI_MOD_EXT_REP_LE )
+    if( m->ext_rep & MBEDTLS_MPI_MOD_EXT_REP_LE )
         return mbedtls_mpi_core_read_le( X, m->n, buf, buflen );
 
-    else if( m->ext_rep & MBEDTLS_MI_MOD_EXT_REP_BE )
+    else if( m->ext_rep & MBEDTLS_MPI_MOD_EXT_REP_BE )
         return mbedtls_mpi_core_read_be( X, m->n, buf, buflen );
 
     else
@@ -430,10 +430,10 @@
                                unsigned char *buf,
                                size_t buflen )
 {
-    if( m->ext_rep & MBEDTLS_MI_MOD_EXT_REP_LE )
+    if( m->ext_rep & MBEDTLS_MPI_MOD_EXT_REP_LE )
         return mbedtls_mpi_core_write_le( X, m->n, buf, buflen );
 
-    else if( m->ext_rep & MBEDTLS_MI_MOD_EXT_REP_BE )
+    else if( m->ext_rep & MBEDTLS_MPI_MOD_EXT_REP_BE )
         return mbedtls_mpi_core_write_be( X, m->n, buf, buflen );
 
     else