diff --git a/newsfragments/1621.fix.rst b/newsfragments/1621.fix.rst
new file mode 100644
index 0000000000..2eb869c969
--- /dev/null
+++ b/newsfragments/1621.fix.rst
@@ -0,0 +1,2 @@
+On macOS and BSDs, explicitly close our wakeup socketpair when we're
+done with it.
diff --git a/trio/_core/_io_kqueue.py b/trio/_core/_io_kqueue.py
index d2d80a7341..be8e9f1819 100644
--- a/trio/_core/_io_kqueue.py
+++ b/trio/_core/_io_kqueue.py
@@ -44,6 +44,7 @@ def statistics(self):
 
     def close(self):
         self._kqueue.close()
+        self._force_wakeup.close()
 
     def force_wakeup(self):
         self._force_wakeup.wakeup_thread_and_signal_safe()