diff --git a/lisp/gnus/nnimap.el b/lisp/gnus/nnimap.el
index d797e893f5..bceba574ca 100644
--- a/lisp/gnus/nnimap.el
+++ b/lisp/gnus/nnimap.el
@@ -407,8 +407,19 @@ nnimap-keepalive
 		      (time-subtract
 		       now
 		       (nnimap-last-command-time nnimap-object))))
-            (ignore-errors              ;E.g. "buffer foo has no process".
-              (nnimap-send-command "NOOP"))))))))
+	    (ignore-errors
+	      (nnimap-send-command "NOOP"))
+	    ;; If our connection has died in the meantime, clean it
+	    ;; and its buffer up.
+	    (unless (memq (process-status (get-buffer-process buffer))
+			  '(open run))
+	      (setq nnimap-process-buffers
+		    (delq buffer nnimap-process-buffers))
+	      (setq nnimap-connection-alist
+		    (seq-filter (lambda (elt)
+				  (null (eq buffer (cdr elt)))
+				  nnimap-connection-alist)))
+	      (kill-buffer buffer))))))))
 
 (defun nnimap-open-connection (buffer)
   ;; Be backwards-compatible -- the earlier value of nnimap-stream was
@@ -1910,6 +1921,10 @@ nnimap-find-connection
 		     '(open run)))
 	  (get-buffer-process (cadr entry))
 	(setq nnimap-connection-alist (delq entry nnimap-connection-alist))
+	(setq nnimap-process-buffers
+	      (delq (cadr entry) nnimap-process-buffers))
+	(when (buffer-live-p (cadr entry))
+	  (kill-buffer (cadr entry)))
 	nil))))
 
 ;; Leave room for `open-network-stream' to issue a couple of IMAP