diff --git a/ChangeLog b/ChangeLog
index d9421183e8..9fd1251536 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Aug 14 00:51:14 2013  Tanaka Akira  <akr@fsij.org>
+
+	* bignum.c (bigdivrem_restoring): xn argument removed.
+	  (bigdivrem_normal): Follow the above change.
+
 Wed Aug 14 00:18:39 2013  Tanaka Akira  <akr@fsij.org>
 
 	* bignum.c (big_div_struct): Remove xn and j field.  Add zn field.
diff --git a/bignum.c b/bignum.c
index e751eb2749..675ea15fd2 100644
--- a/bignum.c
+++ b/bignum.c
@@ -2696,7 +2696,7 @@ bigdivrem_single(BDIGIT *qds, const BDIGIT *xds, size_t xn, BDIGIT y)
 }
 
 static void
-bigdivrem_restoring(BDIGIT *zds, size_t zn, size_t xn, BDIGIT *yds, size_t yn)
+bigdivrem_restoring(BDIGIT *zds, size_t zn, BDIGIT *yds, size_t yn)
 {
     struct big_div_struct bds;
     size_t ynzero;
@@ -2709,7 +2709,7 @@ bigdivrem_restoring(BDIGIT *zds, size_t zn, size_t xn, BDIGIT *yds, size_t yn)
     bds.yds = yds + ynzero;
     bds.stop = Qfalse;
     bds.zn = zn - ynzero;
-    if (xn > 10000 || yn > 10000) {
+    if (bds.zn > 10000 || bds.yn > 10000) {
       retry:
 	bds.stop = Qfalse;
 	rb_thread_call_without_gvl(bigdivrem1, &bds, rb_big_stop, &bds);
@@ -2742,7 +2742,7 @@ bigdivrem_normal(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, BDIGIT *y
     }
     if (xn+1 < zn) zds[xn+1] = 0;
 
-    bigdivrem_restoring(zds, zn, xn, yds, yn);
+    bigdivrem_restoring(zds, zn, yds, yn);
 
     if (needs_mod && shift) {
         bary_small_rshift(zds, zds, yn, shift, 0);