diff --git a/bumblebee/util.py b/bumblebee/util.py
index f35ce89..730ed87 100644
--- a/bumblebee/util.py
+++ b/bumblebee/util.py
@@ -23,7 +23,7 @@ def bytefmt(num):
         if num < 1024.0:
             return "{:.2f}{}B".format(num, unit)
         num /= 1024.0
-    return "{:05.2f%}{}GiB".format(num)
+    return "{:.2f}GiB".format(num*1024.0)
 
 def durationfmt(duration):
     minutes, seconds = divmod(duration, 60)
diff --git a/tests/test_util.py b/tests/test_util.py
new file mode 100644
index 0000000..b9b04c4
--- /dev/null
+++ b/tests/test_util.py
@@ -0,0 +1,25 @@
+# pylint: disable=C0103,C0111
+
+import unittest
+
+from bumblebee.util import *
+
+class TestUtil(unittest.TestCase):
+    def test_bytefmt(self):
+        value = 10
+        display = 10
+        units = [ "B", "KiB", "MiB", "GiB" ]
+        for unit in units:
+            self.assertEquals(bytefmt(value), "{:.2f}{}".format(display, unit))
+            value *= 1024
+        self.assertEquals(bytefmt(value), "{:.2f}GiB".format(display*1024))
+
+    def test_durationfmt(self):
+        self.assertEquals(durationfmt(00), "00:00")
+        self.assertEquals(durationfmt(25), "00:25")
+        self.assertEquals(durationfmt(60), "01:00")
+        self.assertEquals(durationfmt(119), "01:59")
+        self.assertEquals(durationfmt(3600), "01:00:00")
+        self.assertEquals(durationfmt(7265), "02:01:05")
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4