diff --git a/Lib/popen2.py b/Lib/popen2.py
index 4c42958..d4b5d26 100644
--- a/Lib/popen2.py
+++ b/Lib/popen2.py
@@ -91,7 +91,8 @@
     w.close()
     assert r.read() == teststr
     assert e.read() == ""
-    _cleanup()
+    for inst in _active[:]:
+        inst.wait()
     assert not _active
     print "All OK"