diff --git a/ChangeLog b/ChangeLog
index 4233bcfb1..dabbc89f0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2008-05-22  Stéphane Voltz <stef.dev@free.fr>
+	* backend/rts8891.c:
+	minor tweak for scanjet 4470cx
+
 2008-05-21  m. allan noah <kitno455 a t gmail d o t com>
 	* include/sane/saneopts.h: add sane 1.1.0 well-known button options
 	* backend/fujitsu.c: v1.0.63, use sane 1.1.0 well-known option
diff --git a/backend/rts8891.c b/backend/rts8891.c
index 224cf9581..2b13cde5e 100644
--- a/backend/rts8891.c
+++ b/backend/rts8891.c
@@ -1115,9 +1115,6 @@ sane_start (SANE_Handle handle)
   sanei_rts88xx_write_reg (dev->devnum, LAMP_BRIGHT_REG,
 			   dev->regs + LAMP_BRIGHT_REG);
 
-  /* light source to use */
-  light = 0x3b;
-
   /* step 1: locate scan area by doing a scan, then goto calibration area */
   /* we also detect if the sensor type is inadequate and then change it   */
   do
@@ -1148,6 +1145,16 @@ sane_start (SANE_Handle handle)
     }
   while (changed);
 
+  /* light source to use */
+  if (dev->sensor == SENSOR_TYPE_XPA)
+    {
+      light = 0x3f;
+    }
+  else
+    {
+      light = 0x3b;
+    }
+
   /* step 2: dark calibration */
   status = dark_calibration (dev, light);
   if (status != SANE_STATUS_GOOD)