diff --git a/lisp/tramp.el b/lisp/tramp.el
index 40ab3249..23fce076 100644
--- a/lisp/tramp.el
+++ b/lisp/tramp.el
@@ -4769,6 +4769,7 @@ Do not set it manually, it is used buffer-local in `tramp-get-lock-pid'.")
   "Add ad-hoc proxy definitions to `tramp-default-proxies-alist'."
   (when-let ((hops (tramp-file-name-hop vec))
 	     (item vec))
+    (let (signal-hook-function)
     (dolist (proxy (reverse (split-string hops tramp-postfix-hop-regexp 'omit)))
       (let* ((host-port (tramp-file-name-host-port item))
 	     (user-domain (tramp-file-name-user-domain item))
@@ -4787,7 +4788,7 @@ Do not set it manually, it is used buffer-local in `tramp-get-lock-pid'.")
     ;; Save the new value.
     (when tramp-save-ad-hoc-proxies
       (customize-save-variable
-       'tramp-default-proxies-alist tramp-default-proxies-alist))))
+       'tramp-default-proxies-alist tramp-default-proxies-alist)))))

 (defun tramp-compute-multi-hops (vec)
   "Expands VEC according to `tramp-default-proxies-alist'."