diff --git a/README.md b/README.md
index d61adbf..5453492 100644
--- a/README.md
+++ b/README.md
@@ -10,8 +10,8 @@ To finish a todo entry, simply remove the line of text from the textbox.
 
 ## Requirements ##
 
- * SilverStripe 3.1 or newer
+ * SilverStripe 4 or newer
 
 ## Maintainers ##
 
- * Ingo Schommer (ingo at silverstripe dot com)
\ No newline at end of file
+ * Ingo Schommer (ingo at silverstripe dot com)
diff --git a/_config/config.yml b/_config/config.yml
index 6ecd788..dc66b94 100644
--- a/_config/config.yml
+++ b/_config/config.yml
@@ -1,8 +1,9 @@
 ---
 Name: todoextension
-After: 'framework/*','cms/*'
+After:
+  - 'framework/*'
 ---
 
-SiteTree:
+SilverStripe\CMS\Model\SiteTree:
   extensions:
-    - SiteTreePageTodoExtension
\ No newline at end of file
+    - Silverstripe\ToDo\Extension
diff --git a/code/SideReportTodo.php b/code/SideReportTodo.php
deleted file mode 100644
index 4e70361..0000000
--- a/code/SideReportTodo.php
+++ /dev/null
@@ -1,31 +0,0 @@
-<?php
-/**
- * @package cms
- * @subpackage content
- */
-class SideReport_ToDo extends SS_Report {
-	function title() {
-		return _t('SideReport.TODO',"Pages with To Do items");
-	}
-	function group() {
-		return _t('SideReport.ContentGroupTitle', "Content reports");
-	}
-	function sort() {
-		return 0;
-	}
-	function sourceRecords($params = null) {
-		return DataObject::get("SiteTree", "\"SiteTree\".\"ToDo\" IS NOT NULL AND \"SiteTree\".\"ToDo\" <> ''", "\"SiteTree\".\"LastEdited\" DESC");
-	}
-	function columns() {
-		return array(
-			"Title" => array(
-				"title" => "Title", // todo: use NestedTitle(2)
-				"link" => true,
-			),
-			"ToDo" => array(
-				"title" => "ToDo",
-				"newline" => true,
-			), 
-		);
-	}
-}
\ No newline at end of file
diff --git a/code/SiteTreePageTodoExtension.php b/code/SiteTreePageTodoExtension.php
deleted file mode 100644
index 8a008c4..0000000
--- a/code/SiteTreePageTodoExtension.php
+++ /dev/null
@@ -1,21 +0,0 @@
-<?php
-class SiteTreePageTodoExtension extends DataExtension {
-	
-
-	private static $db = array(
-		"ToDo" => "Text"
-	);
-	
-	function updateCMSFields(FieldList $fields) {
-		if (!$fields->hasField('ToDo')) {
-			$fields->addFieldToTab('Root', new Tab(_t('SiteTree.TABTODO', 'To-do') . ($this->owner->ToDo ? '**' : ''),
-				new LiteralField("ToDoHelp", _t('SiteTree.TODOHELP', "<p>You can use this to keep track of work that needs to be done to the content of your site.  To see all your pages with to do information, open the 'Site Reports' window on the left and select 'To Do'</p>")),
-				new TextareaField("ToDo", "", 10)
-			));
-		}
-	}
-	
-	function updateFieldLabels(&$labels) {
-		$labels['ToDo'] = _t('SiteTree.ToDo', 'Todo Notes');
-	}
-}
\ No newline at end of file
diff --git a/composer.json b/composer.json
index 47c5bd6..845e79b 100644
--- a/composer.json
+++ b/composer.json
@@ -1,28 +1,33 @@
 {
-	"name": "silverstripe-labs/silverstripe-page-todo",
-	"description": "Fork of old todo code used in Silverstripe 2.4 updated for 3.1",
-	"type": "silverstripe-module",
-	"keywords": ["silverstripe", "extension"],
-    "license": "BSD-3-Clause",
-	"authors": [
+  "name": "silverstripe-labs/silverstripe-page-todo",
+  "description": "Fork of old todo code used in Silverstripe 2.4 updated for 4.0",
+  "type": "silverstripe-module",
+  "keywords": ["silverstripe", "extension"],
+  "license": "BSD-3-Clause",
+  "authors": [
     {
       "name": "Ingo Schommer",
       "email": "ingo@silverstripe.com",
       "homepage": "http://www.silverstripe.com",
       "role": "Maintainer"
     }
-	],
-	"support": {
-		"issues": "https://github.com/silverstripe-labs/silverstripe-page-todo/issues"
-	},
-	"require": {
-		"silverstripe/framework": "3.*",
-		"silverstripe/cms": "3.*",
-		"composer/installers": "*"
-	},
-	"suggest": {
-	},
-	"extra": {
-		"installer-name": "todo"
-	}
+  ],
+  "support": {
+    "issues": "https://github.com/silverstripe-labs/silverstripe-page-todo/issues"
+  },
+  "require": {
+    "silverstripe/framework": "^4.0@dev",
+    "silverstripe/cms": "^4.0@dev",
+    "composer/installers": "*"
+  },
+    "autoload": {
+      "psr-4": {
+        "Silverstripe\\ToDo\\": "src/"
+      }
+    },
+  "suggest": {
+  },
+  "extra": {
+    "installer-name": "todo"
+  }
 }
diff --git a/src/Extension.php b/src/Extension.php
new file mode 100644
index 0000000..2beab56
--- /dev/null
+++ b/src/Extension.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace Silverstripe\ToDo;
+
+use SilverStripe\ORM\DataExtension;
+
+use SilverStripe\Forms\FieldList;
+use SilverStripe\Forms\LiteralField;
+use SilverStripe\Forms\Tab;
+use SilverStripe\Forms\TextareaField;
+
+class Extension extends DataExtension
+{
+    private static $db = array(
+        'ToDo' => 'Text'
+    );
+
+    function updateCMSFields(FieldList $fields) {
+        if (!$fields->hasField('ToDo')) {
+            $fields->addFieldToTab('Root', new Tab(_t('SiteTree.TABTODO', 'To-do') . ($this->owner->ToDo ? '**' : ''),
+                new LiteralField('ToDoHelp', _t('SiteTree.TODOHELP', '<p>You can use this to keep track of work that needs to be done to the content of your site.  To see all your pages with to do information, open the \'Site Reports\' window on the left and select \'To Do\'</p>')),
+                new TextareaField('ToDo', '', 10)
+            ));
+        }
+    }
+
+    function updateFieldLabels(&$labels) {
+        $labels['ToDo'] = _t('SiteTree.ToDo', 'Todo Notes');
+    }
+}
diff --git a/src/Report.php b/src/Report.php
new file mode 100644
index 0000000..332ec4c
--- /dev/null
+++ b/src/Report.php
@@ -0,0 +1,42 @@
+<?php
+
+namespace Silverstripe\ToDo;
+
+use SilverStripe\Reports\Report as Base_Report;
+use SilverStripe\ORM\DataObject;
+
+/**
+ * @package cms
+ * @subpackage content
+ */
+class Report extends Base_Report
+{
+    function title() {
+        return _t('SideReport.TODO','Pages with To Do items');
+    }
+
+    function group() {
+        return _t('SideReport.ContentGroupTitle', 'Content reports');
+    }
+
+    function sort() {
+        return 0;
+    }
+
+    function sourceRecords($params = null) {
+        return DataObject::get('SilverStripe\CMS\Model\SiteTree', '"SiteTree"."ToDo" IS NOT NULL AND "SiteTree"."ToDo" <> \'\'', '"SiteTree"."LastEdited" DESC');
+    }
+
+    function columns() {
+        return array(
+            'Title' => array(
+                'title' => 'Title', // todo: use NestedTitle(2)
+                'link' => true,
+            ),
+            'ToDo' => array(
+                'title' => 'ToDo',
+                'newline' => true,
+            ),
+        );
+    }
+}