diff --git a/conf/machine/raspberrypi.conf b/conf/machine/raspberrypi.conf
index 4c90637..c94286b 100755
--- a/conf/machine/raspberrypi.conf
+++ b/conf/machine/raspberrypi.conf
@@ -10,7 +10,7 @@ require conf/machine/include/tune-arm1176jzf-s.inc
 GUI_MACHINE_CLASS = "bigscreen"
 
 INHERIT += "sdcard_image-rpi"
-IMAGE_FSTYPES += "tar.bz2 ext3 rpi-sdimg"
+IMAGE_FSTYPES ?= "tar.bz2 ext3 rpi-sdimg"
 
 SERIAL_CONSOLE = "115200 ttyAMA0"