diff --git a/scrapy/linkextractors/htmlparser.py b/scrapy/linkextractors/htmlparser.py
index dcc261b31..9867e1179 100644
--- a/scrapy/linkextractors/htmlparser.py
+++ b/scrapy/linkextractors/htmlparser.py
@@ -3,6 +3,7 @@ HTMLParser-based link extractor
 """
 
 import warnings
+import six
 from six.moves.html_parser import HTMLParser
 from six.moves.urllib.parse import urljoin
 
@@ -39,7 +40,7 @@ class HtmlParserLinkExtractor(HTMLParser):
         ret = []
         base_url = urljoin(response_url, self.base_url) if self.base_url else response_url
         for link in links:
-            if isinstance(link.url, unicode):
+            if isinstance(link.url, six.text_type):
                 link.url = link.url.encode(response_encoding)
             try:
                 link.url = urljoin(base_url, link.url)
diff --git a/scrapy/linkextractors/sgml.py b/scrapy/linkextractors/sgml.py
index 9938e071f..c68dae4c8 100644
--- a/scrapy/linkextractors/sgml.py
+++ b/scrapy/linkextractors/sgml.py
@@ -1,6 +1,7 @@
 """
 SGMLParser-based Link extractors
 """
+import six
 from six.moves.urllib.parse import urljoin
 import warnings
 from sgmllib import SGMLParser
@@ -40,7 +41,7 @@ class BaseSgmlLinkExtractor(SGMLParser):
         if base_url is None:
             base_url = urljoin(response_url, self.base_url) if self.base_url else response_url
         for link in self.links:
-            if isinstance(link.url, unicode):
+            if isinstance(link.url, six.text_type):
                 link.url = link.url.encode(response_encoding)
             try:
                 link.url = urljoin(base_url, link.url)