diff --git a/mercurial/util.py b/mercurial/util.py
index ac89a23ca814340e714101bd65c96c1e2877354b_bWVyY3VyaWFsL3V0aWwucHk=..23a125545c3d6108648dc48986417261aabcfa5d_bWVyY3VyaWFsL3V0aWwucHk= 100644
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -1186,7 +1186,7 @@
     for multiplier, divisor, format in _byteunits:
         if nbytes >= divisor * multiplier:
             return format % (nbytes / float(divisor))
-    return units[-1][2] % nbytes
+    return _byteunits[-1][2] % nbytes
 
 def uirepr(s):
     # Avoid double backslash in Windows path repr()