diff --git a/Formula/p/pidof.rb b/Formula/p/pidof.rb
index 4850ad075ec63f..e8b22957fb7507 100644
--- a/Formula/p/pidof.rb
+++ b/Formula/p/pidof.rb
@@ -1,17 +1,13 @@
 class Pidof < Formula
   desc "Display the PID number for a given process name"
-  homepage "http://www.nightproductions.net/cli.htm"
-  url "http://www.nightproductions.net/downloads/pidof_source.tar.gz"
+  # `nightproductions.net` is no longer accessible, use internet archive urls instead.
+  homepage "https://web.archive.org/web/20240808152721/http://www.nightproductions.net/cli.htm"
+  url "https://web.archive.org/web/20240808152721/http://www.nightproductions.net/downloads/pidof_source.tar.gz"
   mirror "https://distfiles.macports.org/pidof/pidof_source.tar.gz"
   version "0.1.4"
   sha256 "2a2cd618c7b9130e1a1d9be0210e786b85cbc9849c9b6f0cad9cbde31541e1b8"
   license :cannot_represent
 
-  livecheck do
-    url :homepage
-    regex(/href=.*?pidof[^>]+>\s*Download \(v?(\d+(?:\.\d+)+)\)</i)
-  end
-
   bottle do
     rebuild 2
     sha256 cellar: :any_skip_relocation, arm64_sequoia:  "4ec5871a736544b3d218e48cb3883ae457aa097eb0b9a37e666d069d00080fb4"
@@ -30,6 +26,9 @@ class Pidof < Formula
     sha256 cellar: :any_skip_relocation, el_capitan:     "d02c826db5564d7750c0e309a771b164f7764250507955d0b87d09837c3c2ba6"
   end
 
+  # `nightproductions.net` is no longer accessible
+  deprecate! date: "2025-01-12", because: :repo_removed
+
   # Hard dependency on sys/proc.h, which isn't available on Linux
   depends_on :macos