diff --git a/lib/random/formatter.rb b/lib/random/formatter.rb
index 0548e86..037f9d8 100644
--- a/lib/random/formatter.rb
+++ b/lib/random/formatter.rb
@@ -165,7 +165,7 @@ def urlsafe_base64(n=nil, padding=false)
   #
   # The result contains 122 random bits (15.25 random bytes).
   #
-  # See RFC4122[https://datatracker.ietf.org/doc/html/rfc4122] for details of UUID.
+  # See RFC4122[https://www.rfc-editor.org/rfc/rfc4122] for details of UUID.
   #
   def uuid
     ary = random_bytes(16)