diff --git a/library/bignum.c b/library/bignum.c
index 142c4c6..043bd6a 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -1973,7 +1973,7 @@
 
     /* Ensure that target MPI has exactly the same number of limbs
      * as the upper bound, even if the upper bound has leading zeros.
-     * This is necessary for the mbedtls_mpi_lt_mpi_ct() check. */
+     * This is necessary for mbedtls_mpi_core_random. */
     int ret = mbedtls_mpi_resize_clear( X, N->n );
     if( ret != 0 )
         return( ret );