diff --git a/scrapy/core/downloader/__init__.py b/scrapy/core/downloader/__init__.py
index fa8ac01e5..d908f4d7e 100644
--- a/scrapy/core/downloader/__init__.py
+++ b/scrapy/core/downloader/__init__.py
@@ -204,5 +204,4 @@ class Downloader:
         mintime = time() - age
         for key, slot in list(self.slots.items()):
             if not slot.active and slot.lastseen + slot.delay < mintime:
-                inactive_slot = self.slots.pop(key)
-                inactive_slot.close()
+                self.slots.pop(key).close()