diff --git a/meta-digi-arm/conf/machine/ccardimx28js.conf b/meta-digi-arm/conf/machine/ccardimx28js.conf
index 7f7582489..0a111e0f0 100644
--- a/meta-digi-arm/conf/machine/ccardimx28js.conf
+++ b/meta-digi-arm/conf/machine/ccardimx28js.conf
@@ -11,7 +11,7 @@ UBOOT_CONFIG[ccardimx28js] = "ccardimx28js_config"
 KERNEL_DEVICETREE = "imx28-${MACHINE}.dtb"
 
 # Serial console
-SERIAL_CONSOLES = "115200;ttyAMA0"
+SERIAL_CONSOLES ?= "115200;ttyAMA0"
 
 # Bluetooth tty
 BT_TTY ?= "ttyAPP0"
diff --git a/meta-digi-arm/conf/machine/ccimx6ulsbc.conf b/meta-digi-arm/conf/machine/ccimx6ulsbc.conf
index eb03ffb63..f3448a6e5 100644
--- a/meta-digi-arm/conf/machine/ccimx6ulsbc.conf
+++ b/meta-digi-arm/conf/machine/ccimx6ulsbc.conf
@@ -16,7 +16,7 @@ KERNEL_DEVICETREE ?= " \
     imx6ul-ccimx6ulsbc-id135.dtb \
 "
 
-SERIAL_CONSOLES = "115200;ttymxc4"
+SERIAL_CONSOLES ?= "115200;ttymxc4"
 
 MACHINE_FEATURES += "second-eth"
 
diff --git a/meta-digi-arm/conf/machine/ccimx6ulstarter.conf b/meta-digi-arm/conf/machine/ccimx6ulstarter.conf
index 81beaca28..184b980a8 100644
--- a/meta-digi-arm/conf/machine/ccimx6ulstarter.conf
+++ b/meta-digi-arm/conf/machine/ccimx6ulstarter.conf
@@ -16,7 +16,7 @@ KERNEL_DEVICETREE ?= " \
     imx6ul-ccimx6ulstarter-id129.dtb \
 "
 
-SERIAL_CONSOLES = "115200;ttymxc4"
+SERIAL_CONSOLES ?= "115200;ttymxc4"
 
 # Bluetooth tty
 BT_TTY ?= "ttymxc0"