diff --git a/conf/layer.conf b/conf/layer.conf
index 3a4d1ed..f93698c 100644
--- a/conf/layer.conf
+++ b/conf/layer.conf
@@ -2,11 +2,11 @@
 BBPATH := "${BBPATH}:${LAYERDIR}"
 
 # We have a packages directory, add to BBFILES
-BBFILES := "${BBFILES} ${LAYERDIR}/recipes-*/*/*.bb ${LAYERDIR}/recipes-*/*/*.bbappend"
-BBFILES := "${BBFILES} ${LAYERDIR}/yocto-shared/*.bbappend"
+BBFILES += "${LAYERDIR}/recipes-*/*/*.bb ${LAYERDIR}/recipes-*/*/*.bbappend"
+BBFILES += "${LAYERDIR}/yocto-shared/*.bbappend"
 
 # Now we will need to include the matching fixes for a yocto version
-BBFILES := "${BBFILES} ${BBFILES_SYSMOCOM_BSP}"
+BBFILES += "${BBFILES_SYSMOCOM_BSP}"
 
 # selects specific distro or master when DISTRO_VERSION contains SNAPSHOT
 BBFILES_SYSMOCOM_BSP = "${LAYERDIR}/yocto-${@ [dict([('1.5','dora'), ('1.1.2','edison')])[d.getVar('DISTRO_VERSION', True)], 'master']['SNAPSHOT' in d.getVar('DISTRO_VERSION', True)]}/*.bbappend"