diff --git a/ChangeLog b/ChangeLog
index fd6cdd003b..7facce3d8d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sat Jun 21 16:21:07 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* numeric.c (flo_round): get rid of overflow.
+
 Sat Jun 21 15:57:15 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/rdoc/parsers/parse_rb.rb (RDoc#collect_first_comment): skip
diff --git a/numeric.c b/numeric.c
index 318d6046f3..187044ee5e 100644
--- a/numeric.c
+++ b/numeric.c
@@ -1299,11 +1299,16 @@ flo_round(int argc, VALUE *argv, VALUE num)
     while  (--i >= 0)
 	f = f*10.0;
 
-    if (ndigits < 0) number /= f;
-    else number *= f;
-    number = round(number);
-    if (ndigits < 0) number *= f;
-    else number /= f;
+    if (isinf(f)) {
+	if (ndigits < 0) number = 0;
+    }
+    else {
+	if (ndigits < 0) number /= f;
+	else number *= f;
+	number = round(number);
+	if (ndigits < 0) number *= f;
+	else number /= f;
+    }
 
     if (ndigits > 0) return DOUBLE2NUM(number);