1 files changed, 1 insertions, 0 deletions
diff --git a/lib.c b/lib.c
index 663831cc..4674ff26 100644
--- a/lib.c
+++ b/lib.c
@@ -4612,6 +4612,7 @@ static val do_iff(val env, val args)
 
 val iff(val condfun, val thenfun, val elsefun)
 {
+  elsefun = default_bool_arg(elsefun);
   return func_f0v(cons(condfun, cons(thenfun, elsefun)), do_iff);
 }