diff --git a/py/test/config.py b/py/test/config.py
index 08ac4057e..db4af0e1e 100644
--- a/py/test/config.py
+++ b/py/test/config.py
@@ -8,12 +8,15 @@ optparse = py.compat.optparse
 
 # XXX move to Config class
 basetemp = None
+_pid = None
 def ensuretemp(string, dir=1): 
     """ return temporary directory path with
         the given string as the trailing part. 
     """ 
-    global basetemp
-    if basetemp is None: 
+    global basetemp, _pid
+    currpid = py.std.os.getpid()
+    if basetemp is None or _pid != currpid:
+        _pid = currpid
         basetemp = py.path.local.make_numbered_dir(prefix='pytest-')
     return basetemp.ensure(string, dir=dir) 
   
diff --git a/py/test/testing/test_config.py b/py/test/testing/test_config.py
index 275f57503..0bde2f057 100644
--- a/py/test/testing/test_config.py
+++ b/py/test/testing/test_config.py
@@ -10,6 +10,21 @@ def test_tmpdir():
     assert d1 == d2
     assert d1.check(dir=1) 
 
+def test_ensuretemp_fork():
+    os = py.std.os
+    org_getpid = os.getpid
+    currpid = 0
+    def getpid():
+        return currpid
+    try:
+        os.getpid = getpid
+        d1 = py.test.ensuretemp('hello')
+        currpid = 1
+        d2 = py.test.ensuretemp('hello')
+    finally:
+        os.getpid = org_getpid
+    assert d1 != d2
+
 def test_config_cmdline_options(): 
     o = py.test.ensuretemp('configoptions') 
     o.ensure("conftest.py").write(py.code.Source("""