2 files changed, 5 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog
index b245074cb6..534c35cc8a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sat Jun 15 17:14:32 2013  Tanaka Akira  <akr@fsij.org>
+
+	* bignum.c (bigmul1_normal): Shrink the result Bignum length.
+
 Sat Jun 15 10:19:42 2013  Zachary Scott  <zachary@zacharyscott.net>
 
 	* ext/bigdecimal/bigdecimal.c: Update overview formatting of headers
diff --git a/bignum.c b/bignum.c
index f347a2ff5b..8cbdce8819 100644
--- a/bignum.c
+++ b/bignum.c
@@ -3139,7 +3139,7 @@ bigmul1_single(VALUE x, VALUE y)
 static VALUE
 bigmul1_normal(VALUE x, VALUE y)
 {
-    long xl = RBIGNUM_LEN(x), yl = RBIGNUM_LEN(y), i, j = xl + yl + 1;
+    long xl = RBIGNUM_LEN(x), yl = RBIGNUM_LEN(y), i, j = xl + yl;
     BDIGIT_DBL n = 0;
     VALUE z = bignew(j, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y));
     BDIGIT *xds, *yds, *zds;