Index: Lib/distutils/tests/test_sysconfig.py
===================================================================
--- Lib/distutils/tests/test_sysconfig.py	(revision 65034)
+++ Lib/distutils/tests/test_sysconfig.py	(working copy)
@@ -17,6 +17,8 @@
         # XXX doesn't work on Linux when Python was never installed before
         #self.assert_(os.path.isdir(lib_dir), lib_dir)
         # test for pythonxx.lib?
+        self.assertNotEqual(sysconfig.get_python_lib(),
+                            sysconfig.get_python_lib(prefix=TESTFN))
 
     def test_get_python_inc(self):
         # The check for srcdir is copied from Python's setup.py,
Index: Lib/distutils/sysconfig.py
===================================================================
--- Lib/distutils/sysconfig.py	(revision 65034)
+++ Lib/distutils/sysconfig.py	(working copy)
@@ -129,7 +129,7 @@
             if get_python_version() < "2.2":
                 return prefix
             else:
-                return os.path.join(PREFIX, "Lib", "site-packages")
+                return os.path.join(prefix, "Lib", "site-packages")
 
     elif os.name == "mac":
         if plat_specific:
@@ -145,9 +145,9 @@
 
     elif os.name == "os2":
         if standard_lib:
-            return os.path.join(PREFIX, "Lib")
+            return os.path.join(prefix, "Lib")
         else:
-            return os.path.join(PREFIX, "Lib", "site-packages")
+            return os.path.join(prefix, "Lib", "site-packages")
 
     else:
         raise DistutilsPlatformError(