diff --git a/nrf5/Makefile b/nrf5/Makefile
index c8d852f6ad..7aa0dd52a7 100644
--- a/nrf5/Makefile
+++ b/nrf5/Makefile
@@ -63,7 +63,7 @@ INC += -I./hal/$(MCU_VARIANT)
 INC += -I./drivers/display
 INC += -I../lib/mp-readline
 
-NRF_DEFINES = -D$(MCU_VARIANT_UPPER)
+NRF_DEFINES += -D$(MCU_VARIANT_UPPER)
 NRF_DEFINES += -DCONFIG_GPIO_AS_PINRESET
 
 CFLAGS_CORTEX_M = -mthumb -mabi=aapcs -fsingle-precision-constant -Wdouble-promotion
@@ -159,7 +159,7 @@ DRIVERS_SRC_C += $(addprefix drivers/,\
 #ifeq ($(SD), )
 
 SRC_C += \
-	device/$(MCU_VARIANT)/system_$(MCU_VARIANT).c \
+	device/$(MCU_VARIANT)/system_$(MCU_SUB_VARIANT).c \
 
 SRC_S = \
 	device/$(MCU_VARIANT)/startup_$(MCU_VARIANT).s \
diff --git a/nrf5/boards/microbit/mpconfigboard.mk b/nrf5/boards/microbit/mpconfigboard.mk
index c8a0f0caea..f959edab50 100644
--- a/nrf5/boards/microbit/mpconfigboard.mk
+++ b/nrf5/boards/microbit/mpconfigboard.mk
@@ -1,5 +1,5 @@
 MCU_SERIES = m0
 MCU_VARIANT = nrf51
-LD_FILE = boards/nrf51822_aa.ld
+MCU_SUB_VARIANT = nrf51822
+LD_FILE = boards/$(MCU_SUB_VARIANT)_aa.ld
 FLASHER = pyocd
-
diff --git a/nrf5/boards/pca10000/mpconfigboard.mk b/nrf5/boards/pca10000/mpconfigboard.mk
index d2a566aea8..523653ede0 100644
--- a/nrf5/boards/pca10000/mpconfigboard.mk
+++ b/nrf5/boards/pca10000/mpconfigboard.mk
@@ -1,4 +1,5 @@
 MCU_SERIES = m0
 MCU_VARIANT = nrf51
-LD_FILE = boards/nrf51822_aa.ld
+MCU_SUB_VARIANT = nrf51822
+LD_FILE = boards/$(MCU_SUB_VARIANT)_aa.ld
 
diff --git a/nrf5/boards/pca10001/mpconfigboard.mk b/nrf5/boards/pca10001/mpconfigboard.mk
index 40a74fd176..269fdc95af 100644
--- a/nrf5/boards/pca10001/mpconfigboard.mk
+++ b/nrf5/boards/pca10001/mpconfigboard.mk
@@ -1,3 +1,4 @@
 MCU_SERIES = m0
 MCU_VARIANT = nrf51
-LD_FILE = boards/nrf51822_aa.ld
+MCU_SUB_VARIANT = nrf51822
+LD_FILE = boards/$(MCU_SUB_VARIANT)_aa.ld
diff --git a/nrf5/boards/pca10028/mpconfigboard.mk b/nrf5/boards/pca10028/mpconfigboard.mk
index ac92424ec7..01b6bcf7e1 100644
--- a/nrf5/boards/pca10028/mpconfigboard.mk
+++ b/nrf5/boards/pca10028/mpconfigboard.mk
@@ -1,4 +1,4 @@
 MCU_SERIES = m0
 MCU_VARIANT = nrf51
-LD_FILE = boards/nrf51822_ac.ld
-
+MCU_SUB_VARIANT = nrf51822
+LD_FILE = boards/$(MCU_SUB_VARIANT)_ac.ld
diff --git a/nrf5/boards/pca10031/mpconfigboard.mk b/nrf5/boards/pca10031/mpconfigboard.mk
index 72a21aa76f..01b6bcf7e1 100644
--- a/nrf5/boards/pca10031/mpconfigboard.mk
+++ b/nrf5/boards/pca10031/mpconfigboard.mk
@@ -1,3 +1,4 @@
 MCU_SERIES = m0
 MCU_VARIANT = nrf51
-LD_FILE = boards/nrf51822_ac.ld
+MCU_SUB_VARIANT = nrf51822
+LD_FILE = boards/$(MCU_SUB_VARIANT)_ac.ld
diff --git a/nrf5/boards/pca10040/mpconfigboard.mk b/nrf5/boards/pca10040/mpconfigboard.mk
index 3b6af95f75..62fce4c795 100644
--- a/nrf5/boards/pca10040/mpconfigboard.mk
+++ b/nrf5/boards/pca10040/mpconfigboard.mk
@@ -1,4 +1,6 @@
 MCU_SERIES = m4
 MCU_VARIANT = nrf52
-LD_FILE = boards/nrf52832_aa.ld
+MCU_SUB_VARIANT = nrf52832
+LD_FILE = boards/$(MCU_SUB_VARIANT)_aa.ld
 
+NRF_DEFINES += -DNRF52832_XXAA
diff --git a/nrf5/boards/pca10056/mpconfigboard.mk b/nrf5/boards/pca10056/mpconfigboard.mk
index 2e273dabc7..15a88ed091 100644
--- a/nrf5/boards/pca10056/mpconfigboard.mk
+++ b/nrf5/boards/pca10056/mpconfigboard.mk
@@ -1,4 +1,6 @@
 MCU_SERIES = m4
 MCU_VARIANT = nrf52
-LD_FILE = boards/nrf52840_aa.ld
+MCU_SUB_VARIANT = nrf52840
+LD_FILE = boards/$(MCU_SUB_VARIANT)_aa.ld
 
+NRF_DEFINES += -DNRF52840_XXAA