diff --git a/tests/run-tests.py b/tests/run-tests.py
--- a/tests/run-tests.py
+++ b/tests/run-tests.py
@@ -459,6 +459,7 @@ if not options.child:
 os.environ['LANG'] = os.environ['LC_ALL'] = 'C'
 os.environ['TZ'] = 'GMT'
 os.environ["EMAIL"] = "Foo Bar <foo.bar@example.com>"
+os.environ['CDPATH'] = ''
 
 TESTDIR = os.environ["TESTDIR"] = os.getcwd()
 HGTMP = os.environ['HGTMP'] = tempfile.mkdtemp('', 'hgtests.', options.tmpdir)