diff --git a/ChangeLog.md b/ChangeLog.md
index df1d533..eb5358e 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,13 @@
 # CHANGELOG MODULE DECLARATIONTVA FOR [DOLIBARR ERP CRM](https://www.dolibarr.org)
 
+## 2.5.11
+
+### Bug Fixes
+- **Fixed TCPDF Loading**: Added proper TCPDF include statement before custom class definition
+- **Class Loading**: Ensured TCPDF is loaded before extending it with custom PDF class
+- **Error Resolution**: Fixed "Class TCPDF not found" error
+- **Stable Implementation**: Custom PDF class now works correctly with proper dependencies
+
 ## 2.5.10
 
 ### Bug Fixes
diff --git a/core/class/declarationtva_pdf.class.php b/core/class/declarationtva_pdf.class.php
index 97dd2bd..0fd3dff 100644
--- a/core/class/declarationtva_pdf.class.php
+++ b/core/class/declarationtva_pdf.class.php
@@ -15,6 +15,11 @@
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  */
 
+// Ensure TCPDF is loaded
+if (!class_exists('TCPDF')) {
+    require_once DOL_DOCUMENT_ROOT . '/includes/tcpdf/tcpdf.php';
+}
+
 /**
  * Custom PDF class with footer functionality
  */
diff --git a/core/modules/modDeclarationTVA.class.php b/core/modules/modDeclarationTVA.class.php
index b266819..1f37fa0 100644
--- a/core/modules/modDeclarationTVA.class.php
+++ b/core/modules/modDeclarationTVA.class.php
@@ -76,7 +76,7 @@ class modDeclarationTVA extends DolibarrModules
 		$this->editor_squarred_logo = '';					// Must be image filename into the module/img directory followed with @modulename. Example: 'myimage.png@declarationtva'
 
 		// Possible values for version are: 'development', 'experimental', 'dolibarr', 'dolibarr_deprecated', 'experimental_deprecated' or a version string like 'x.y.z'
-        $this->version = '2.5.10';
+        $this->version = '2.5.11';
 		// Url to the file with your last numberversion of this module
 		//$this->url_last_version = 'http://www.example.com/versionmodule.txt';