diff --git a/beeprint/helpers/string.py b/beeprint/helpers/string.py
index b8765a6..43afd54 100644
--- a/beeprint/helpers/string.py
+++ b/beeprint/helpers/string.py
@@ -16,7 +16,7 @@
 def calc_width(s):
     if hasattr(urwid, 'util'):
         return urwid.util.calc_width(s, 0, len(s))
-    return urwid.str_util.calc_width(s, 0, len(s))
+    return urwid.old_str_util.calc_width(s, 0, len(s))
 
 
 def cut_string(s, length):