diff --git a/setuptools/package_index.py b/setuptools/package_index.py
index 5619e4da72..362e26f3e1 100644
--- a/setuptools/package_index.py
+++ b/setuptools/package_index.py
@@ -217,7 +217,7 @@ def wrapper(*args, **kwargs):
     return wrapper
 
 
-REL = re.compile(r"""<([^>]*\srel\s*=\s*['"]?([^'">]+)[^>]*)>""", re.I)
+REL = re.compile(r"""<([^>]*\srel\s{0,10}=\s{0,10}['"]?([^'" >]+)[^>]*)>""", re.I)
 """
 Regex for an HTML tag with 'rel="val"' attributes.
 """
diff --git a/setuptools/tests/test_packageindex.py b/setuptools/tests/test_packageindex.py
index babc119721..7b0bf1124d 100644
--- a/setuptools/tests/test_packageindex.py
+++ b/setuptools/tests/test_packageindex.py
@@ -307,7 +307,6 @@ def test_percent_in_password(self, temp_home):
         assert cred.password == 'pity%'
 
 
-@pytest.mark.xfail(reason="#3659")
 @pytest.mark.timeout(1)
 def test_REL_DoS():
     """