Update traceback message
diff --git a/Doc/tut/tut.tex b/Doc/tut/tut.tex
index d57d89a..6c3758c 100644
--- a/Doc/tut/tut.tex
+++ b/Doc/tut/tut.tex
@@ -850,7 +850,7 @@
 >>> str(u"äöü")
 Traceback (most recent call last):
   File "<stdin>", line 1, in ?
-UnicodeError: ASCII encoding error: ordinal not in range(128)
+UnicodeEncodeError: 'ascii' codec can't encode characters in position 0-2: ordinal not in range(128)
 \end{verbatim}
 
 To convert a Unicode string into an 8-bit string using a specific