diff --git a/lisp/progmodes/project.el b/lisp/progmodes/project.el
index 9e5a8be5e13..9caf8455af6 100644
--- a/lisp/progmodes/project.el
+++ b/lisp/progmodes/project.el
@@ -906,7 +906,7 @@ in the `project-current' call, the timeout is determined by
                        (project--value-in-dir 'project-vc-ignores dir)))
 
 (defun project--vc-ignores (dir backend extra-ignores)
-  (require 'vc)
+  (require 'vc)             ; Can be removed when we require Emacs 31.1.
   (append
    (when backend
      (delq
diff --git a/lisp/vc/vc-hooks.el b/lisp/vc/vc-hooks.el
index f3519465c07..72345990b2e 100644
--- a/lisp/vc/vc-hooks.el
+++ b/lisp/vc/vc-hooks.el
@@ -290,16 +290,18 @@ if that doesn't exist either, return nil."
       (require (intern (concat "vc-" (downcase (symbol-name backend)))))
       (if (fboundp f) f
 	(let ((def (vc-make-backend-sym 'default fun)))
+          ;; Load vc.el, for default implementations, if needed.
+	  (require 'vc)
 	  (if (fboundp def) (cons def backend) nil))))))
 
 (defun vc-call-backend (backend function-name &rest args)
-  "Call for BACKEND the implementation of FUNCTION-NAME with the given ARGS.
-Calls
+  "Call BACKEND's implementation of FUNCTION-NAME with arguments ARGS.
+Does
 
     (apply #\\='vc-BACKEND-FUN ARGS)
 
 if vc-BACKEND-FUN exists (after trying to find it in vc-BACKEND.el)
-and else calls
+and otherwise does
 
     (apply #\\='vc-default-FUN BACKEND ARGS)