diff --git a/ChangeLog b/ChangeLog
index 36a6dcee..44923c36 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -27,6 +27,11 @@
     Type: bugfix
     Changed: linkcheck/checker/urlbase.py
 
+  * If default encoding cannot be determined, fall back to ASCII.
+    Type: bugfix
+    Changed: linkcheck/i18n.py
+    Closes: SF bug #1524800
+
 4.1 "Tsotsi" (released 29.5.2006)
 
   * Wait for spawned threads to finish before shutdown. Gets rid
diff --git a/linkcheck/i18n.py b/linkcheck/i18n.py
index ea76177c..f1bd1d6a 100644
--- a/linkcheck/i18n.py
+++ b/linkcheck/i18n.py
@@ -27,6 +27,10 @@ import gettext
 supported_languages = ['en']
 default_language = 'en'
 default_encoding = locale.getpreferredencoding()
+# It can happen that the preferrec encoding is not determinable, which
+# means the function returned None. Fall back to ASCII in this case.
+if default_encoding is None:
+    default_encoding = "ascii"
 
 def install_builtin (translator, do_unicode):
     """