diff --git a/core/modules/ckeditor5/ckeditor5.ckeditor5.yml b/core/modules/ckeditor5/ckeditor5.ckeditor5.yml
index 855fc9ce1f67652cad4ca06bde430f752d965b42..99ecb479fdbb21e85dcf91c7b579a979b173566b 100644
--- a/core/modules/ckeditor5/ckeditor5.ckeditor5.yml
+++ b/core/modules/ckeditor5/ckeditor5.ckeditor5.yml
@@ -340,6 +340,10 @@ ckeditor5_link:
   ckeditor5:
     plugins:
       - link.Link
+    config:
+      link:
+        # @see https://ckeditor.com/docs/ckeditor5/latest/features/link.html#adding-default-link-protocol-to-external-links
+        defaultProtocol: 'https://'
   drupal:
     label: Link
     library: core/ckeditor5.link