diff --git a/ChangeLog b/ChangeLog
index 9417f9cf2a..dd498e4862 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Aug 16 00:00:57 2013  Tanaka Akira  <akr@fsij.org>
+
+	* bignum.c (bary_divmod): Simplify an expression.
+
 Thu Aug 15 23:26:12 2013  Tanaka Akira  <akr@fsij.org>
 
 	* bignum.c (bigdivrem_normal): Remove a local variable.
diff --git a/bignum.c b/bignum.c
index 8fb76951e9..a4af506651 100644
--- a/bignum.c
+++ b/bignum.c
@@ -2800,7 +2800,7 @@ bary_divmod(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, s
         if (xn + extra_words <= qn)
             zds = qds;
         else
-            zds = ALLOCV_N(BDIGIT, tmpz, xn + extra_words);
+            zds = ALLOCV_N(BDIGIT, tmpz, zn);
         MEMCPY(zds, xds, BDIGIT, xn);
         BDIGITS_ZERO(zds+xn, zn-xn);