diff --git a/scripts/debian-images-arm64/builders-fai.sh b/scripts/debian-images-arm64/builders-fai.sh
index 0269bf7867cd6386397896cf04b7b81a53e65cf4..3d06800ef70710dbf352a65a0da7f5008665a1cf 100644
--- a/scripts/debian-images-arm64/builders-fai.sh
+++ b/scripts/debian-images-arm64/builders-fai.sh
@@ -19,7 +19,7 @@ wget $CONFIGS_RAW_URL/scripts/debian-images-arm64/debpkgdiff.py
 mknod /dev/loop0 b 7 0
 
 CLASS=$(echo SAVECACHE,${OS_FLAVOUR},DEBIAN,LINARO,QCOM,${ROOTFS},RAW,${CLASS_EXTRA} | tr '[:lower:]' '[:upper:]')
-[ -n "$CLASS_EXTRA" ] && ROOTFS="$ROOTFS-$(echo "$CLASS_EXTRA" | tr -s ',' '-')
+[ -n "$CLASS_EXTRA" ] && ROOTFS="$ROOTFS-$(echo "$CLASS_EXTRA" | tr -s ',' '-')"
 OUT=${VENDOR}-${OS_FLAVOUR}-${ROOTFS}-${PLATFORM_NAME}-${CI_PIPELINE_ID}
 
 fai-diskimage -v --cspace $(pwd) --hostname linaro-${ROOTFS} -S ${ROOTFS_SZ} --class ${CLASS} ${OUT}.img.raw