diff --git a/linkcheck/strformat.py b/linkcheck/strformat.py
index 28b78e74..efdc34ec 100644
--- a/linkcheck/strformat.py
+++ b/linkcheck/strformat.py
@@ -1,5 +1,5 @@
 # -*- coding: iso-8859-1 -*-
-# Copyright (C) 2000-2012 Bastian Kleineidam
+# Copyright (C) 2000-2013 Bastian Kleineidam
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -179,24 +179,24 @@ def remove_markup (s):
     return s
 
 
-def strsize (b):
+def strsize (b, grouping=True):
     """Return human representation of bytes b. A negative number of bytes
     raises a value error."""
     if b < 0:
         raise ValueError("Invalid negative byte number")
     if b < 1024:
-        return u"%sB" % locale.format("%d", b, True)
+        return u"%sB" % locale.format("%d", b, grouping)
     if b < 1024 * 10:
-        return u"%sKB" % locale.format("%d", (b // 1024), True)
+        return u"%sKB" % locale.format("%d", (b // 1024), grouping)
     if b < 1024 * 1024:
-        return u"%sKB" % locale.format("%.2f", (float(b) / 1024), True)
+        return u"%sKB" % locale.format("%.2f", (float(b) / 1024), grouping)
     if b < 1024 * 1024 * 10:
-        return u"%sMB" % locale.format("%.2f", (float(b) / (1024*1024)), True)
+        return u"%sMB" % locale.format("%.2f", (float(b) / (1024*1024)), grouping)
     if b < 1024 * 1024 * 1024:
-        return u"%sMB" % locale.format("%.1f", (float(b) / (1024*1024)), True)
+        return u"%sMB" % locale.format("%.1f", (float(b) / (1024*1024)), grouping)
     if b < 1024 * 1024 * 1024 * 10:
-        return u"%sGB" % locale.format("%.2f", (float(b) / (1024*1024*1024)), True)
-    return u"%sGB" % locale.format("%.1f", (float(b) / (1024*1024*1024)), True)
+        return u"%sGB" % locale.format("%.2f", (float(b) / (1024*1024*1024)), grouping)
+    return u"%sGB" % locale.format("%.1f", (float(b) / (1024*1024*1024)), grouping)
 
 
 def strtime (t):
diff --git a/tests/test_strformat.py b/tests/test_strformat.py
index 049e8542..460ec32b 100644
--- a/tests/test_strformat.py
+++ b/tests/test_strformat.py
@@ -1,5 +1,5 @@
 # -*- coding: iso-8859-1 -*-
-# Copyright (C) 2004-2012 Bastian Kleineidam
+# Copyright (C) 2004-2013 Bastian Kleineidam
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -85,7 +85,7 @@ class TestStrFormat (unittest.TestCase):
         self.assertEqual(linkcheck.strformat.strsize(0), "0B")
         self.assertEqual(linkcheck.strformat.strsize(1), "1B")
         self.assertEqual(linkcheck.strformat.strsize(2), "2B")
-        self.assertEqual(linkcheck.strformat.strsize(1023), "1023B")
+        self.assertEqual(linkcheck.strformat.strsize(1023, grouping=False), "1023B")
         self.assertEqual(linkcheck.strformat.strsize(1024), "1KB")
         self.assertEqual(linkcheck.strformat.strsize(1024*25), "25.00KB")
         self.assertEqual(linkcheck.strformat.strsize(1024*1024), "1.00MB")