diff --git a/3rd/lua/lgc.c b/3rd/lua/lgc.c
index 5c778930..39e25860 100644
--- a/3rd/lua/lgc.c
+++ b/3rd/lua/lgc.c
@@ -652,10 +652,11 @@ static void clearkeys (global_State *g, GCObject *l, GCObject *f) {
     Table *h = gco2t(l);
     Node *n, *limit = gnodelast(h);
     for (n = gnode(h, 0); n < limit; n++) {
-      if (iscleared(g, gkey(n))) {
+      if (!ttisnil(gval(n)) && (iscleared(g, gkey(n)))) {
         setnilvalue(gval(n));  /* remove value ... */
-        removeentry(n);  /* and remove entry from table */
       }
+      if (ttisnil(gval(n)))  /* is entry empty? */
+        removeentry(n);  /* remove entry from table */
     }
   }
 }