diff --git a/impression/wrapper_canon.ml b/impression/wrapper_canon.ml
index 62999070..7d5e69a4 100644
--- a/impression/wrapper_canon.ml
+++ b/impression/wrapper_canon.ml
@@ -52,13 +52,13 @@ let _FitSize () = if !expand then "1" else "0"
 
 let duplex = ref true
 let binding_long_edge = ref true
+let finition = ref "none"
 let _DuplexType() =
-  if !duplex then if !binding_long_edge then "2" else "1" else "0"
+  if !finition = "book" or not !duplex then "0"
+  else if !binding_long_edge then "2" else "1"
 
 let finition = ref "none"
-let _Sort() = match !finition with
-    "none" -> "0"
-  | _ -> "1"
+let _Sort() = match !finition with "none" -> "0" | _ -> "1"
 
 let _StapleType () = List.assoc !finition
   [ "TopLeft","5"; "TopRight","6"; "BottomLeft","7"; "BottomRight","8";