Index: src/wp-includes/revision.php
===================================================================
--- src/wp-includes/revision.php	(revision 43568)
+++ src/wp-includes/revision.php	(working copy)
@@ -109,7 +109,16 @@
  * @return int|WP_Error|void Void or 0 if error, new revision ID, if success.
  */
 function wp_save_post_revision( $post_id ) {
-	if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
+	$autosave = defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE;
+	/**
+	 * Filters whether saving of revisions is allowed during autosaves.
+	 * Normally, it is disallowed whenever the `DOING_AUTOSAVE` constant is truthy.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param bool    $allow Is saving of revisions allowed for autosaves.
+	 */
+	if ( $autosave && ! apply_filters( 'allow_revisions_for_autosave', false ) ) {
 		return;
 	}