diff --git a/Documentation/scripts/generate_how_to_cite.py b/Documentation/scripts/generate_how_to_cite.py
index 1f9233022af..850563d71a3 100644
--- a/Documentation/scripts/generate_how_to_cite.py
+++ b/Documentation/scripts/generate_how_to_cite.py
@@ -142,7 +142,7 @@ def protect_upper_case(title):
 def protect_accentuated_letters(authors):
   res=authors.replace(u"é",r"{\'e}").replace(u"ä",r"{\"a}").replace(u"ö",r"{\"o}").replace(u"ñ",r"{\~n}").replace(u"ã",r"{\~a}").replace(u"ë",r"{\"e}").replace("%","")
   try:
-    res.decode('ascii')
+    res.encode('ascii')
   except UnicodeEncodeError:
     stderr.write("WARNING: a non ascii character has been found in author string for bibtex (probably a non-handled accentuated letter)."
                  "Check the new package added and update the function protect_accentuated_letters in Documentation/scripts/generate_how_to_cite.py\n\n")