diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1eb6cfb..68c7ada 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Change log
 
+## Unreleased
+
+- Minor changes in tutorials.
+
 ## 2.0.6 - 2024-08-14
 
 - Added `PdfSectorTrait` trait and the corresponding tutorial.
diff --git a/doc/tuto_3.md b/doc/tuto_3.md
index e75e396..b241232 100644
--- a/doc/tuto_3.md
+++ b/doc/tuto_3.md
@@ -20,7 +20,7 @@ class CustomDocument extends PdfDocument
         // calculate width of title and position
         $title = $this->getTitle();
         $width = $this->getStringWidth($title) + 6.0;
-        $this->setX((210.0 - $width) / 2.0);
+        $this->setX(($this->width - $width) / 2.0);
         // colors of frame, background and text
         $this->setDrawColor(0, 80, 180);
         $this->setFillColor(230, 230, 0);
diff --git a/doc/tuto_4.md b/doc/tuto_4.md
index c5cbeda..e4198ee 100644
--- a/doc/tuto_4.md
+++ b/doc/tuto_4.md
@@ -24,7 +24,7 @@ class CustomDocument extends PdfDocument
         $title = $this->getTitle();
         $this->setFont(PdfFontName::ARIAL, PdfFontStyle::BOLD, 15);
         $width = $this->getStringWidth($title) + 6.0;
-        $this->setX((210.0 - $width) / 2);
+        $this->setX(($this->width - $width) / 2);
         $this->setDrawColor(0, 80, 180);
         $this->setFillColor(230, 230, 0);
         $this->setTextColor(220, 50, 50);