diff --git a/impression/impression_canon.py b/impression/impression_canon.py
index a6175111..fb89d4ca 100755
--- a/impression/impression_canon.py
+++ b/impression/impression_canon.py
@@ -426,7 +426,7 @@ class impression:
         elif self._settings['papier'] == 'A4':
             options += ' -o PageSize=A4'
         else:
-            options += ' -o pdf-expand -o PageSize=A3'
+            options += ' -o pdf-expand -o pdf-paper=841x1190 -o PageSize=A3'
 
         if self._settings['portrait']:
             if self._settings['recto_verso']: