diff --git a/content/_index.md b/content/_index.md
index 0c31614..63d50c8 100644
--- a/content/_index.md
+++ b/content/_index.md
@@ -96,7 +96,7 @@ You've already created an excellent content type under Structure » Content.
 name: Frankenstein
 type: module
 description: "Rename save button for Frankenstein's content."
-core: 8.x|9.x
+core: 8.x
 ```
    
 
@@ -167,7 +167,8 @@ And we're going to tell you how you can figure out all of that.
 name: Frankenstein
 type: module
 description: "Rename save button for Frankenstein's content."
-core: 8.x|9.x
+core: 8.x
+core_version_requirement: ^8 || ^9
 ```
    
 
@@ -181,6 +182,10 @@ function frankenstein_form_node_frankenstein_form_alter(&$form, \Drupal\Core\For
 }
 ```
 
+{{% note %}}
+   We added the core_version_requirement line to make the module recognizeable to Drupal 9 as well as Drupal 8.
+{{% /note %}}
+
 ---
 
 
@@ -407,7 +412,8 @@ The module does not exist.
 name: "Project Copyright"
 type: module
 description: "Generate a block with the copyright leyend."
-core: "8.x"
+core: 8.x
+core_version_requirement: ^8 || ^9
 ```
 
 ---
@@ -516,6 +522,7 @@ Or someone may make a tiny improvement that makes everyone's lives better.
 ```diff
  type: module
  description: 'Provide workflow buttons for content moderation instead of a select dropdown of states.'
+ core_version_requirement: ^8 || ^9
  core: 8.x
 +configure: workflow_buttons.settings