diff --git a/config/Makefile.conf.defaults b/config/Makefile.conf.defaults
index cafd98b28866030334b16ca498296763d67984e8..4988d5ec081c0d7c25545b1de0c8e5f7c70af14d 100644
--- a/config/Makefile.conf.defaults
+++ b/config/Makefile.conf.defaults
@@ -33,5 +33,8 @@ IMAGE_DIR=$(WORKSPACE)/image_files/
 IMAGE_GIT_URL=https://www.fsmpi.rwth-aachen.de/git/lipstick
 IMAGE_GIT_BRANCH=ss15
 IMAGE_EXTRA_INFO=
+#size of the fat partition; cf. "man truncate" for format/units
+IMAGE_PART_SIZE=6G
+IMAGE_PART_LABEL=MULTIBOOT
 
 GPARTED_VERSION=0.21.0-1