diff --git a/tests/run-tests.py b/tests/run-tests.py
--- a/tests/run-tests.py
+++ b/tests/run-tests.py
@@ -599,11 +599,6 @@ class Test(unittest.TestCase):
         self._testtmp = None
         self._chgsockdir = None
 
-        # If IPv6 is used, set web.ipv6=1 in hgrc so servers will use IPv6
-        if useipv6:
-            self._extraconfigopts = list(self._extraconfigopts)
-            self._extraconfigopts.append('web.ipv6 = True')
-
         # If we're not in --debug mode and reference output file exists,
         # check test output against it.
         if debug:
@@ -935,6 +930,7 @@ class Test(unittest.TestCase):
                    (os.path.join(self._testtmp, b'.cache/largefiles')))
         hgrc.write(b'[web]\n')
         hgrc.write(b'address = localhost\n')
+        hgrc.write(b'ipv6 = %s\n' % self._useipv6)
 
         for opt in self._extraconfigopts:
             section, key = opt.split('.', 1)
diff --git a/tests/test-basic.t b/tests/test-basic.t
--- a/tests/test-basic.t
+++ b/tests/test-basic.t
@@ -12,7 +12,7 @@ Create a repository:
   ui.mergemarkers=detailed
   ui.promptecho=True
   web.address=localhost
-  web.ipv6=True (?)
+  web\.ipv6=(?:True|False) (re)
   $ hg init t
   $ cd t
 
diff --git a/tests/test-commandserver.t b/tests/test-commandserver.t
--- a/tests/test-commandserver.t
+++ b/tests/test-commandserver.t
@@ -200,7 +200,7 @@ check that local configs for the cached 
   ui.foo=bar
   ui.nontty=true
   web.address=localhost
-  web.ipv6=True (?)
+  web\.ipv6=(?:True|False) (re)
   *** runcommand init foo
   *** runcommand -R foo showconfig ui defaults
   defaults.backout=-d "0 0"