diff --git a/lisp/emacs-lisp/seq.el b/lisp/emacs-lisp/seq.el
index 629a7a5fb30..e3037a71901 100644
--- a/lisp/emacs-lisp/seq.el
+++ b/lisp/emacs-lisp/seq.el
@@ -58,6 +58,10 @@
 
 (eval-when-compile (require 'cl-generic))
 
+;; We used to use some sequence functions from cl-lib, but this
+;; dependency was swapped around so that it will be easier to make
+;; seq.el preloaded in the future.  See also Bug#39761#26.
+
 (defmacro seq-doseq (spec &rest body)
   "Loop over a sequence.
 Evaluate BODY with VAR bound to each element of SEQUENCE, in turn.