diff --git a/sympy/utilities/timeutils.py b/sympy/utilities/timeutils.py
index 3770d85..c53594e 100644
--- a/sympy/utilities/timeutils.py
+++ b/sympy/utilities/timeutils.py
@@ -8,7 +8,7 @@ import math
 from sympy.core.compatibility import range
 
 _scales = [1e0, 1e3, 1e6, 1e9]
-_units = [u's', u'ms', u'\N{GREEK SMALL LETTER MU}s', u'ns']
+_units = [u's', u'ms', u'mus', u'ns']
 
 
 def timed(func, setup="pass", limit=None):