diff --git a/CHANGELOG.md b/CHANGELOG.md
index 07d3e7dfb..2d7d71f95 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ The changelog contains informations about bug fixes, new features or bc breaking
 
 - [#1102](https://github.com/luyadev/luya/issues/1102) Removed News Module Tag table and replace by admin modules Tag models.
 - [#1098](https://github.com/luyadev/luya/issues/1098) Changed luya\base\Widget view path behavior to default implementation with option to enable app view paths lookup.
+- [#1109](https://github.com/luyadev/luya/issues/1109) In order to prevent blocks to extend from cms blocks, flag all cms blocks as final.
 
 ### Added
 
diff --git a/modules/cms/src/frontend/blocks/AudioBlock.php b/modules/cms/src/frontend/blocks/AudioBlock.php
index 04b4cb2ba..8a8b9e58f 100644
--- a/modules/cms/src/frontend/blocks/AudioBlock.php
+++ b/modules/cms/src/frontend/blocks/AudioBlock.php
@@ -11,7 +11,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class AudioBlock extends TwigBlock
+final class AudioBlock extends TwigBlock
 {
     /**
      * @inheritDoc
diff --git a/modules/cms/src/frontend/blocks/DevBlock.php b/modules/cms/src/frontend/blocks/DevBlock.php
index ecce2c08e..4d47fa073 100644
--- a/modules/cms/src/frontend/blocks/DevBlock.php
+++ b/modules/cms/src/frontend/blocks/DevBlock.php
@@ -11,7 +11,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class DevBlock extends TwigBlock
+final class DevBlock extends TwigBlock
 {
     public $module = 'cms';
 
diff --git a/modules/cms/src/frontend/blocks/FileListBlock.php b/modules/cms/src/frontend/blocks/FileListBlock.php
index 0f6795daf..b3f30e3b7 100644
--- a/modules/cms/src/frontend/blocks/FileListBlock.php
+++ b/modules/cms/src/frontend/blocks/FileListBlock.php
@@ -11,7 +11,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class FileListBlock extends TwigBlock
+final class FileListBlock extends TwigBlock
 {
     public $module = 'cms';
 
diff --git a/modules/cms/src/frontend/blocks/FormBlock.php b/modules/cms/src/frontend/blocks/FormBlock.php
index 440528fd5..42526374b 100644
--- a/modules/cms/src/frontend/blocks/FormBlock.php
+++ b/modules/cms/src/frontend/blocks/FormBlock.php
@@ -13,7 +13,7 @@
  * @author Basil Suter <basil@nadar.io>
  *
  */
-class FormBlock extends TwigBlock
+final class FormBlock extends TwigBlock
 {
     public $module = 'cms';
 
diff --git a/modules/cms/src/frontend/blocks/HtmlBlock.php b/modules/cms/src/frontend/blocks/HtmlBlock.php
index 2ea786123..366cf3a95 100644
--- a/modules/cms/src/frontend/blocks/HtmlBlock.php
+++ b/modules/cms/src/frontend/blocks/HtmlBlock.php
@@ -11,7 +11,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class HtmlBlock extends TwigBlock
+final class HtmlBlock extends TwigBlock
 {
     public $module = 'cms';
 
diff --git a/modules/cms/src/frontend/blocks/ImageBlock.php b/modules/cms/src/frontend/blocks/ImageBlock.php
index d00573685..ae1b8ee79 100644
--- a/modules/cms/src/frontend/blocks/ImageBlock.php
+++ b/modules/cms/src/frontend/blocks/ImageBlock.php
@@ -14,7 +14,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class ImageBlock extends TwigBlock
+final class ImageBlock extends TwigBlock
 {
     public $module = 'cms';
 
diff --git a/modules/cms/src/frontend/blocks/ImageTextBlock.php b/modules/cms/src/frontend/blocks/ImageTextBlock.php
index dac92d6e9..8e59719cd 100644
--- a/modules/cms/src/frontend/blocks/ImageTextBlock.php
+++ b/modules/cms/src/frontend/blocks/ImageTextBlock.php
@@ -14,7 +14,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class ImageTextBlock extends TwigBlock
+final class ImageTextBlock extends TwigBlock
 {
     public $module = 'cms';
 
diff --git a/modules/cms/src/frontend/blocks/LayoutBlock.php b/modules/cms/src/frontend/blocks/LayoutBlock.php
index 22e774ace..8d2735046 100644
--- a/modules/cms/src/frontend/blocks/LayoutBlock.php
+++ b/modules/cms/src/frontend/blocks/LayoutBlock.php
@@ -11,7 +11,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class LayoutBlock extends TwigBlock
+final class LayoutBlock extends TwigBlock
 {
     public $module = 'cms';
 
diff --git a/modules/cms/src/frontend/blocks/LineBlock.php b/modules/cms/src/frontend/blocks/LineBlock.php
index 40ecc02b7..45bdd8654 100644
--- a/modules/cms/src/frontend/blocks/LineBlock.php
+++ b/modules/cms/src/frontend/blocks/LineBlock.php
@@ -10,7 +10,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class LineBlock extends TwigBlock
+final class LineBlock extends TwigBlock
 {
     public $cacheEnabled = true;
     
diff --git a/modules/cms/src/frontend/blocks/LinkButtonBlock.php b/modules/cms/src/frontend/blocks/LinkButtonBlock.php
index 46956e2a0..76dfcbca1 100644
--- a/modules/cms/src/frontend/blocks/LinkButtonBlock.php
+++ b/modules/cms/src/frontend/blocks/LinkButtonBlock.php
@@ -11,7 +11,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class LinkButtonBlock extends TwigBlock
+final class LinkButtonBlock extends TwigBlock
 {
     public $cacheEnabled = true;
 
diff --git a/modules/cms/src/frontend/blocks/ListBlock.php b/modules/cms/src/frontend/blocks/ListBlock.php
index 31db485d6..061acbcc0 100644
--- a/modules/cms/src/frontend/blocks/ListBlock.php
+++ b/modules/cms/src/frontend/blocks/ListBlock.php
@@ -11,7 +11,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class ListBlock extends TwigBlock
+final class ListBlock extends TwigBlock
 {
     public $module = 'cms';
 
diff --git a/modules/cms/src/frontend/blocks/MapBlock.php b/modules/cms/src/frontend/blocks/MapBlock.php
index 5aa17ee89..ec4524b6f 100644
--- a/modules/cms/src/frontend/blocks/MapBlock.php
+++ b/modules/cms/src/frontend/blocks/MapBlock.php
@@ -10,7 +10,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class MapBlock extends TwigBlock
+final class MapBlock extends TwigBlock
 {
     public $module = 'cms';
     
diff --git a/modules/cms/src/frontend/blocks/ModuleBlock.php b/modules/cms/src/frontend/blocks/ModuleBlock.php
index a53177988..735bf7760 100644
--- a/modules/cms/src/frontend/blocks/ModuleBlock.php
+++ b/modules/cms/src/frontend/blocks/ModuleBlock.php
@@ -16,7 +16,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class ModuleBlock extends TwigBlock
+final class ModuleBlock extends TwigBlock
 {
     public $module = 'cms';
 
diff --git a/modules/cms/src/frontend/blocks/QuoteBlock.php b/modules/cms/src/frontend/blocks/QuoteBlock.php
index 975c0f86f..e506dc60a 100644
--- a/modules/cms/src/frontend/blocks/QuoteBlock.php
+++ b/modules/cms/src/frontend/blocks/QuoteBlock.php
@@ -11,7 +11,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class QuoteBlock extends TwigBlock
+final class QuoteBlock extends TwigBlock
 {
     public $module = 'cms';
 
diff --git a/modules/cms/src/frontend/blocks/SpacingBlock.php b/modules/cms/src/frontend/blocks/SpacingBlock.php
index 5133fee76..70a6bc380 100644
--- a/modules/cms/src/frontend/blocks/SpacingBlock.php
+++ b/modules/cms/src/frontend/blocks/SpacingBlock.php
@@ -10,7 +10,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class SpacingBlock extends TwigBlock
+final class SpacingBlock extends TwigBlock
 {
     public $module = 'cms';
     
diff --git a/modules/cms/src/frontend/blocks/TableBlock.php b/modules/cms/src/frontend/blocks/TableBlock.php
index 996668b2f..cc680bde8 100644
--- a/modules/cms/src/frontend/blocks/TableBlock.php
+++ b/modules/cms/src/frontend/blocks/TableBlock.php
@@ -11,7 +11,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class TableBlock extends TwigBlock
+final class TableBlock extends TwigBlock
 {
     public $module = 'cms';
     
diff --git a/modules/cms/src/frontend/blocks/TextBlock.php b/modules/cms/src/frontend/blocks/TextBlock.php
index 68a23ef45..fde36752c 100644
--- a/modules/cms/src/frontend/blocks/TextBlock.php
+++ b/modules/cms/src/frontend/blocks/TextBlock.php
@@ -12,7 +12,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class TextBlock extends TwigBlock
+final class TextBlock extends TwigBlock
 {
     public $module = 'cms';
     
diff --git a/modules/cms/src/frontend/blocks/TitleBlock.php b/modules/cms/src/frontend/blocks/TitleBlock.php
index 528bf37a3..f961b27d1 100644
--- a/modules/cms/src/frontend/blocks/TitleBlock.php
+++ b/modules/cms/src/frontend/blocks/TitleBlock.php
@@ -11,7 +11,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class TitleBlock extends TwigBlock
+final class TitleBlock extends TwigBlock
 {
     public $module = 'cms';
     
diff --git a/modules/cms/src/frontend/blocks/VideoBlock.php b/modules/cms/src/frontend/blocks/VideoBlock.php
index 247541dc5..8fc064c95 100644
--- a/modules/cms/src/frontend/blocks/VideoBlock.php
+++ b/modules/cms/src/frontend/blocks/VideoBlock.php
@@ -11,7 +11,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class VideoBlock extends TwigBlock
+final class VideoBlock extends TwigBlock
 {
     public $module = 'cms';
 
diff --git a/modules/cms/src/frontend/blocks/WysiwygBlock.php b/modules/cms/src/frontend/blocks/WysiwygBlock.php
index e64cbe9e8..a5366e43c 100644
--- a/modules/cms/src/frontend/blocks/WysiwygBlock.php
+++ b/modules/cms/src/frontend/blocks/WysiwygBlock.php
@@ -11,7 +11,7 @@
  *
  * @author Basil Suter <basil@nadar.io>
  */
-class WysiwygBlock extends TwigBlock
+final class WysiwygBlock extends TwigBlock
 {
     /**
      * @inheritDoc