diff --git a/src/closure.c b/src/closure.c
index ff3109c..f32f7f6 100755
--- a/src/closure.c
+++ b/src/closure.c
@@ -1,6 +1,6 @@
 /* Closures for Bison
 
-   Copyright (C) 1984, 1989, 2000, 2001, 2002, 2004, 2005, 2007 Free
+   Copyright (C) 1984, 1989, 2000, 2001, 2002, 2004, 2005, 2007, 2008 Free
    Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
@@ -123,17 +123,16 @@ print_fderives (void)
 static void
 set_firsts (void)
 {
-  symbol_number i, j;
+  rule_number r;
 
   firsts = bitsetv_create (nvars, nvars, BITSET_FIXED);
 
-  for (i = ntokens; i < nsyms; i++)
-    for (j = 0; derives[i - ntokens][j]; ++j)
-      {
-	item_number sym = derives[i - ntokens][j]->rhs[0];
-	if (ISVAR (sym))
-	  bitset_set (FIRSTS (i), sym - ntokens);
-      }
+  for (r = 0; r < nrules; r++)
+    {
+      item_number sym = rules[r].rhs[0];
+      if (ISVAR (sym))
+	bitset_set (FIRSTS (rules[r].lhs->number), sym - ntokens);
+    }
 
   if (trace_flag & trace_sets)
     bitsetv_matrix_dump (stderr, "RTC: Firsts Input", firsts);