diff --git a/tests/test-lock.py b/tests/test-lock.py
--- a/tests/test-lock.py
+++ b/tests/test-lock.py
@@ -141,7 +141,7 @@
         state.assertacquirecalled(True)
 
         # fake a fork
-        forklock = copy.deepcopy(lock)
+        forklock = copy.copy(lock)
         forklock._pidoffset = 1
         forklock.release()
         state.assertreleasecalled(False)
@@ -238,7 +238,7 @@
             childstate.assertacquirecalled(True)
 
             # fork the child lock
-            forkchildlock = copy.deepcopy(childlock)
+            forkchildlock = copy.copy(childlock)
             forkchildlock._pidoffset += 1
             forkchildlock.release()
             childstate.assertreleasecalled(False)