diff --git a/src/attr/_make.py b/src/attr/_make.py
index fc44611..f60016e 100644
--- a/src/attr/_make.py
+++ b/src/attr/_make.py
@@ -3,7 +3,10 @@ from __future__ import absolute_import, division, print_function
 import hashlib
 import linecache
 import sys
-import threading
+try:
+    import threading
+except ImportError:
+    import dummy_threading as threading
 import warnings
 
 from operator import itemgetter