diff --git a/meta-digi-arm/conf/machine/ccimx6qpsbc.conf b/meta-digi-arm/conf/machine/ccimx6qpsbc.conf
index 600c3de96..e44ca6382 100644
--- a/meta-digi-arm/conf/machine/ccimx6qpsbc.conf
+++ b/meta-digi-arm/conf/machine/ccimx6qpsbc.conf
@@ -43,7 +43,7 @@ BT_TTY ?= "ttymxc1"
 # XBee
 XBEE_TTY ?= "ttymxc4"
 
-# Flash image types
-IMAGE_FSTYPES ?= "boot.vfat ext4.gz sdcard.gz tar.bz2 recovery.vfat"
-# Add SQUASHFS if read-only-rootfs is enabled
-IMAGE_FSTYPES += '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", "squashfs", "", d)}'
+# Image FS types
+IMAGE_FSTYPES ?= '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", \
+				       "boot.vfat tar.bz2 recovery.vfat squashfs", \
+				       "boot.vfat ext4.gz sdcard.gz tar.bz2 recovery.vfat", d)}'
diff --git a/meta-digi-arm/conf/machine/ccimx6sbc.conf b/meta-digi-arm/conf/machine/ccimx6sbc.conf
index fbfa29d65..361bf5ec1 100644
--- a/meta-digi-arm/conf/machine/ccimx6sbc.conf
+++ b/meta-digi-arm/conf/machine/ccimx6sbc.conf
@@ -45,7 +45,7 @@ BT_TTY ?= "ttymxc1"
 # XBee
 XBEE_TTY ?= "ttymxc4"
 
-# Flash image types
-IMAGE_FSTYPES ?= "boot.vfat ext4.gz sdcard.gz tar.bz2 recovery.vfat"
-# Add SQUASHFS if read-only-rootfs is enabled
-IMAGE_FSTYPES += '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", "squashfs", "", d)}'
+# Image FS types
+IMAGE_FSTYPES ?= '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", \
+				       "boot.vfat tar.bz2 recovery.vfat squashfs", \
+				       "boot.vfat ext4.gz sdcard.gz tar.bz2 recovery.vfat", d)}'
diff --git a/meta-digi-arm/conf/machine/ccimx6ulsbc.conf b/meta-digi-arm/conf/machine/ccimx6ulsbc.conf
index 0d2f75472..77142f4dc 100644
--- a/meta-digi-arm/conf/machine/ccimx6ulsbc.conf
+++ b/meta-digi-arm/conf/machine/ccimx6ulsbc.conf
@@ -39,7 +39,7 @@ BT_TTY ?= "ttymxc0"
 # XBee
 XBEE_TTY ?= "ttymxc1"
 
-# Flash image types
-IMAGE_FSTYPES ?= "tar.bz2 ubifs boot.ubifs recovery.ubifs"
-# Add SQUASHFS if read-only-rootfs is enabled
-IMAGE_FSTYPES += '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", "squashfs", "", d)}'
+# Image FS types
+IMAGE_FSTYPES ?= '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", \
+				       "tar.bz2 boot.ubifs recovery.ubifs squashfs", \
+				       "tar.bz2 ubifs boot.ubifs recovery.ubifs", d)}'
diff --git a/meta-digi-arm/conf/machine/ccimx6ulstarter.conf b/meta-digi-arm/conf/machine/ccimx6ulstarter.conf
index f09e2b233..327016beb 100644
--- a/meta-digi-arm/conf/machine/ccimx6ulstarter.conf
+++ b/meta-digi-arm/conf/machine/ccimx6ulstarter.conf
@@ -35,10 +35,10 @@ SERIAL_CONSOLES ?= "115200;ttymxc4"
 # Bluetooth tty
 BT_TTY ?= "ttymxc0"
 
-# Flash image types
-IMAGE_FSTYPES ?= "tar.bz2 ubifs boot.ubifs recovery.ubifs"
-# Add SQUASHFS if read-only-rootfs is enabled
-IMAGE_FSTYPES += '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", "squashfs", "", d)}'
+# Image FS types
+IMAGE_FSTYPES ?= '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", \
+				       "tar.bz2 boot.ubifs recovery.ubifs squashfs", \
+				       "tar.bz2 ubifs boot.ubifs recovery.ubifs", d)}'
 
 # Default image for install scripts
 DEFAULT_IMAGE_NAME ?= "core-image-base"
diff --git a/meta-digi-arm/conf/machine/ccimx8mm-dvk.conf b/meta-digi-arm/conf/machine/ccimx8mm-dvk.conf
index 4baf8830a..3b7c4ea4a 100644
--- a/meta-digi-arm/conf/machine/ccimx8mm-dvk.conf
+++ b/meta-digi-arm/conf/machine/ccimx8mm-dvk.conf
@@ -41,7 +41,7 @@ XBEE_RESET_N_GPIO ?= "mca-gpio@15,gpio1@8"
 XBEE_SLEEP_RQ_GPIO ?= "mca-gpio@11,gpio1@7"
 XBEE_TTY ?= "ttymxc3"
 
-# Flash image types
-IMAGE_FSTYPES ?= "boot.vfat ext4.gz sdcard.gz tar.bz2 recovery.vfat"
-# Add SQUASHFS if read-only-rootfs is enabled
-IMAGE_FSTYPES += '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", "squashfs", "", d)}'
+# Image FS types
+IMAGE_FSTYPES ?= '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", \
+				       "boot.vfat tar.bz2 recovery.vfat squashfs", \
+				       "boot.vfat ext4.gz sdcard.gz tar.bz2 recovery.vfat", d)}'
diff --git a/meta-digi-arm/conf/machine/ccimx8mn-dvk.conf b/meta-digi-arm/conf/machine/ccimx8mn-dvk.conf
index b4c8cb281..15cc06038 100644
--- a/meta-digi-arm/conf/machine/ccimx8mn-dvk.conf
+++ b/meta-digi-arm/conf/machine/ccimx8mn-dvk.conf
@@ -43,7 +43,7 @@ XBEE_RESET_N_GPIO ?= "mca-gpio@15,gpio1@8"
 XBEE_SLEEP_RQ_GPIO ?= "mca-gpio@11,gpio1@7"
 XBEE_TTY ?= "ttymxc3"
 
-# Flash image types
-IMAGE_FSTYPES ?= "boot.vfat ext4.gz sdcard.gz tar.bz2 recovery.vfat"
-# Add SQUASHFS if read-only-rootfs is enabled
-IMAGE_FSTYPES += '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", "squashfs", "", d)}'
+# Image FS types
+IMAGE_FSTYPES ?= '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", \
+				       "boot.vfat tar.bz2 recovery.vfat squashfs", \
+				       "boot.vfat ext4.gz sdcard.gz tar.bz2 recovery.vfat", d)}'
diff --git a/meta-digi-arm/conf/machine/ccimx8x-sbc-express.conf b/meta-digi-arm/conf/machine/ccimx8x-sbc-express.conf
index ff455a55a..b39ca65f4 100644
--- a/meta-digi-arm/conf/machine/ccimx8x-sbc-express.conf
+++ b/meta-digi-arm/conf/machine/ccimx8x-sbc-express.conf
@@ -29,7 +29,7 @@ XBEE_RESET_N_GPIO ?= "gpio3@13"
 XBEE_SLEEP_RQ_GPIO ?= "gpio3@16"
 XBEE_TTY ?= "ttyLP0"
 
-# Flash image types
-IMAGE_FSTYPES ?= "boot.vfat ext4.gz sdcard.gz tar.bz2 recovery.vfat"
-# Add SQUASHFS if read-only-rootfs is enabled
-IMAGE_FSTYPES += '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", "squashfs", "", d)}'
+# Image FS types
+IMAGE_FSTYPES ?= '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", \
+				       "boot.vfat tar.bz2 recovery.vfat squashfs", \
+				       "boot.vfat ext4.gz sdcard.gz tar.bz2 recovery.vfat", d)}'
diff --git a/meta-digi-arm/conf/machine/ccimx8x-sbc-pro.conf b/meta-digi-arm/conf/machine/ccimx8x-sbc-pro.conf
index 5b061b9aa..1c2c72f29 100644
--- a/meta-digi-arm/conf/machine/ccimx8x-sbc-pro.conf
+++ b/meta-digi-arm/conf/machine/ccimx8x-sbc-pro.conf
@@ -42,8 +42,7 @@ XBEE_RESET_N_GPIO ?= "mca-gpio@15"
 XBEE_SLEEP_RQ_GPIO ?= "mca-gpio@11"
 XBEE_TTY ?= "ttyMCA0"
 
-
-# Flash image types
-IMAGE_FSTYPES ?= "boot.vfat ext4.gz sdcard.gz tar.bz2 recovery.vfat"
-# Add SQUASHFS if read-only-rootfs is enabled
-IMAGE_FSTYPES += '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", "squashfs", "", d)}'
+# Image FS types
+IMAGE_FSTYPES ?= '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", \
+				       "boot.vfat tar.bz2 recovery.vfat squashfs", \
+				       "boot.vfat ext4.gz sdcard.gz tar.bz2 recovery.vfat", d)}'