gcl.git - GNU Common Lisp

diff --git a/gcl/o/sgbc.c b/gcl/o/sgbc.c
index 9e0f53a53..9c265ba4d 100755
--- a/gcl/o/sgbc.c
+++ b/gcl/o/sgbc.c

@@ -227,7 +227,7 @@ sgc_mark_object1(object x) {

if (x->ht.ht_self == NULL)

break;

for (i = 0, j = x->ht.ht_size; i < j; i++) {

- if (ON_WRITABLE_PAGE(&x->ht.ht_self[i])) {

+ if (x->ht.ht_self[i].hte_key!=OBJNULL && ON_WRITABLE_PAGE(&x->ht.ht_self[i])) {

sgc_mark_object(x->ht.ht_self[i].hte_key);

sgc_mark_object(x->ht.ht_self[i].hte_value);

}