diff --git a/extlib/benz/codegen.c b/extlib/benz/codegen.c
index 2470c8f8..1cd02594 100644
--- a/extlib/benz/codegen.c
+++ b/extlib/benz/codegen.c
@@ -701,8 +701,8 @@ codegen_context_destroy(pic_state *pic, codegen_context *cxt)
   irep->localc = (int)cxt->locals->len;
   irep->capturec = (int)cxt->captures->len;
   irep->code = pic_realloc(pic, cxt->code, sizeof(pic_code) * cxt->clen);
-  irep->irep = pic_realloc(pic, cxt->irep, sizeof(struct pic_irep *) * cxt->ilen);
-  irep->ilen = cxt->ilen;
+  irep->irep = pic_realloc(pic, cxt->irep, sizeof(struct pic_irep *) * (cxt->ilen + 1));
+  irep->irep[cxt->ilen] = NULL;
   irep->pool = pic_realloc(pic, cxt->pool, sizeof(pic_value) * cxt->plen);
   irep->plen = cxt->plen;
 
diff --git a/extlib/benz/include/picrin/irep.h b/extlib/benz/include/picrin/irep.h
index 63d9a8eb..64fde79b 100644
--- a/extlib/benz/include/picrin/irep.h
+++ b/extlib/benz/include/picrin/irep.h
@@ -31,7 +31,6 @@ struct pic_irep {
   int argc, localc, capturec;
   bool varg;
   struct pic_irep **irep;
-  size_t ilen;
   pic_value *pool;
   size_t plen;
 };
diff --git a/extlib/benz/proc.c b/extlib/benz/proc.c
index ab067ced..3c897448 100644
--- a/extlib/benz/proc.c
+++ b/extlib/benz/proc.c
@@ -13,7 +13,7 @@ pic_irep_incref(pic_state PIC_UNUSED(*pic), struct pic_irep *irep)
 void
 pic_irep_decref(pic_state *pic, struct pic_irep *irep)
 {
-  size_t i;
+  struct pic_irep **i;
 
   if (--irep->refc == 0) {
     pic_free(pic, irep->code);
@@ -23,8 +23,9 @@ pic_irep_decref(pic_state *pic, struct pic_irep *irep)
     irep->list.prev->next = irep->list.next;
     irep->list.next->prev = irep->list.prev;
 
-    for (i = 0; i < irep->ilen; ++i) {
-      pic_irep_decref(pic, irep->irep[i]);
+    i = irep->irep;
+    while (*i) {
+      pic_irep_decref(pic, *i++);
     }
     pic_free(pic, irep->irep);
     pic_free(pic, irep);