diff --git a/gunicorn/arbiter.py b/gunicorn/arbiter.py
index 542c610b..bf2a3bc6 100644
--- a/gunicorn/arbiter.py
+++ b/gunicorn/arbiter.py
@@ -367,7 +367,7 @@ class Arbiter(object):
         # do we need to change listener ?
         if old_address != self.cfg.address:
             # close all listeners
-            [l.close for l in self.LISTENERS]
+            [l.close() for l in self.LISTENERS]
             # init new listeners
             self.LISTENERS = create_sockets(self.cfg, self.log)
             self.log.info("Listening at: %s", ",".join(str(self.LISTENERS)))