diff --git a/numpy/distutils/misc_util.py b/numpy/distutils/misc_util.py
index 8136f8f4f0dd..9276774ad018 100644
--- a/numpy/distutils/misc_util.py
+++ b/numpy/distutils/misc_util.py
@@ -24,11 +24,12 @@
 # store all created temporary directories so they can be deleted on exit
 _tmpdirs = []
 def clean_up_temporary_directory():
-    for d in _tmpdirs:
-        try:
-            shutil.rmtree(d)
-        except OSError:
-            pass
+    if _tmpdirs is not None:
+        for d in _tmpdirs:
+            try:
+                shutil.rmtree(d)
+            except OSError:
+                pass
 
 atexit.register(clean_up_temporary_directory)