--- a/python/mozlint/mozlint/roller.py
+++ b/python/mozlint/mozlint/roller.py
@@ -138,18 +138,21 @@ class LintRoller(object):
         workers = []
         for i in range(num_procs):
             workers.append(
                 pool.apply_async(_run_worker, args=(queue, paths), kwds=self.lintargs))
         pool.close()
 
         # ignore SIGINT in parent so we can still get partial results
         # from child processes. These should shutdown quickly anyway.
-        signal.signal(signal.SIGINT, signal.SIG_IGN)
+        orig_sigint = signal.signal(signal.SIGINT, signal.SIG_IGN)
         self.failed = []
         for worker in workers:
             # parent process blocks on worker.get()
             results, failed = worker.get()
             if failed:
                 self.failed.extend(failed)
             for k, v in results.iteritems():
                 all_results[k].extend(v)
+
+        signal.signal(signal.SIGINT, orig_sigint)
+        m.shutdown()
         return all_results