diff --git a/src/zc/buildout/testing.py b/src/zc/buildout/testing.py
index af8974052589099fe31f7e779ff9a51e6c01d8b6..f50c7cb2ab54b3c042a24b801e1c4d084c1f4fa9 100644
--- a/src/zc/buildout/testing.py
+++ b/src/zc/buildout/testing.py
@@ -157,8 +157,8 @@ def buildoutSetUp(test):
         del os.environ['HOME'] # pop doesn't truly remove it :(
         register_teardown(lambda: os.environ.__setitem__('HOME', old_home))
 
-    base = tempfile.mkdtemp()
-    register_teardown(lambda: shutil.rmtree(base))
+    base = tempfile.mkdtemp('buildoutSetUp')
+    register_teardown(lambda base=base: shutil.rmtree(base))
     base = os.path.join(base, '_TEST_')
     os.mkdir(base)