diff --git a/scan b/scan
index bb49042..7798566 100755
--- a/scan
+++ b/scan
@@ -245,7 +245,10 @@ fi;
 
 echo >&2 "Scanning..."
 #eval strace -f -o /tmp/scan-trace.txt scanadf -d $DEVICE $MAXPAGE $PGHEIGHT $PGWIDTH -S $SCRIPT --script-wait --resolution $RESOLUTION --mode $MODE $DESKEW $CROP $SOURCE -o scan-%04d
-eval scanadf -d \'"$DEVICE"\' $MAXPAGE $PGHEIGHT $PGWIDTH -S $SCRIPT --script-wait --resolution $RESOLUTION --mode $MODE $DESKEW $CROP $DRIVER_OPTION $SOURCE -o $TMP_DIR/scan-%04d
+if test -n "$MODE"; then
+  mode="--mode $MODE"
+fi
+eval scanadf -d \'"$DEVICE"\' $MAXPAGE $PGHEIGHT $PGWIDTH -S $SCRIPT --script-wait --resolution $RESOLUTION $MODE $DESKEW $CROP $DRIVER_OPTION $SOURCE -o $TMP_DIR/scan-%04d
 
 shopt -s extglob nullglob
 pdffiles=($TMP_DIR/scan-[0-9]*.pdf)