1 files changed, 1 insertions, 1 deletions
diff --git a/sc2.c b/sc2.c
index 904458a..e72de95 100644
--- a/sc2.c
+++ b/sc2.c
@@ -147,10 +147,10 @@ SCM appendb(args)
  tail:
   if NULLP(args) return EOL;
   arg = CAR(args);
-  ASSERT(NULLP(arg) || (NIMP(arg) && CONSP(arg)), arg, ARG1, s_appendb);
   args = CDR(args);
   if NULLP(args) return arg;
   if NULLP(arg) goto tail;
+  ASSERT(NIMP(arg) && CONSP(arg), arg, ARG1, s_appendb);
   CDR(last_pair(arg)) = appendb(args);
   return arg;
 }