diff --git a/src/teletext/renderer.py b/src/teletext/renderer.py
index 5731485..f9f37d2 100755
--- a/src/teletext/renderer.py
+++ b/src/teletext/renderer.py
@@ -266,7 +266,7 @@ class TeletextCanvas(QWidget):
         # Header string for Row 0 columns 0-7
         header_prefix = ""
         if row == 0 and self.page:
-            header_prefix = f"P{self.page.magazine}{self.page.page_number:02d}"
+            header_prefix = f"P{self.page.magazine}{self.page.page_number:02X}"
             # Pad to 8 chars
             header_prefix = header_prefix.ljust(8)