diff --git a/config/Makefile.conf.defaults b/config/Makefile.conf.defaults
index b1457039610851549039e72bfac6350e311dbbe8..4077b0dcd089bbf32427b2bedf71704c20d565f8 100644
--- a/config/Makefile.conf.defaults
+++ b/config/Makefile.conf.defaults
@@ -29,7 +29,7 @@ ISO_PATTERN_FLAGS=
 
 APT_SOURCE_URL_OVERRIDE=http://ftp.halifax.rwth-aachen.de/ubuntu/
 
-IMAGE_DIR=$(WORKSPACE)/image_files/
+IMAGE_DIR=$(WORKSPACE)/image_files
 IMAGE_GIT_URL=https://www.fsmpi.rwth-aachen.de/git/lipstick
 IMAGE_GIT_BRANCH=ss15
 IMAGE_EXTRA_INFO=