diff --git a/scrapy/selector/libxml2sel.py b/scrapy/selector/libxml2sel.py
index f5fec4f93..d6ef7ebb1 100644
--- a/scrapy/selector/libxml2sel.py
+++ b/scrapy/selector/libxml2sel.py
@@ -54,7 +54,7 @@ class XPathSelector(object_ref):
     def re(self, regex):
         """Return a list of unicode strings by applying the regex over all
         current XPath selections, and flattening the results"""
-        return extract_regex(regex, self.extract(), 'utf-8')
+        return extract_regex(regex, self.extract())
 
     def extract(self):
         """Return a unicode string of the content referenced by the XPathSelector"""
diff --git a/scrapy/selector/lxmlsel.py b/scrapy/selector/lxmlsel.py
index e4b4682af..ae7166ccb 100644
--- a/scrapy/selector/lxmlsel.py
+++ b/scrapy/selector/lxmlsel.py
@@ -59,7 +59,7 @@ class XPathSelector(object_ref):
         return XPathSelectorList(result)
 
     def re(self, regex):
-        return extract_regex(regex, self.extract(), 'utf-8')
+        return extract_regex(regex, self.extract())
 
     def extract(self):
         try: