diff --git a/sexp2rsa.c b/sexp2rsa.c
index 2c0006ed087f7a4c2ca2d1b6aa2f03b97837dff2..82410ff61e36618233a3bb9f5cdd2ef84b46e730 100644
--- a/sexp2rsa.c
+++ b/sexp2rsa.c
@@ -66,9 +66,7 @@ rsa_keypair_from_sexp(struct rsa_public_key *pub,
   struct sexp_iterator values[8];
   unsigned nvalues;
   
-  sexp_iterator_init(&i, length, expr);
-
-  if (!sexp_iterator_next(&i))
+  if (!sexp_iterator_first(&i, length, expr))
     return 0;
   
   if (priv)