diff --git a/boards/common/nrf52/Makefile.include b/boards/common/nrf52/Makefile.include
index d0fa753cd2..bc9c85d141 100644
--- a/boards/common/nrf52/Makefile.include
+++ b/boards/common/nrf52/Makefile.include
@@ -18,7 +18,7 @@ ifeq (jlink,$(PROGRAMMER))
 
   # special options when using SoftDevice
   ifneq (,$(filter nordic_softdevice_ble,$(USEPKG)))
-    export JLINK_PRE_FLASH := loadfile $(BINDIR)/softdevice.hex
+    JLINK_PRE_FLASH = loadfile $(BINDIR)/softdevice.hex
     FLASH_ADDR = 0x1f000
     LINKER_SCRIPT ?= $(RIOTCPU)/$(CPU)/ldscripts/$(CPU_MODEL)_sd.ld
     # murdock: softdevice.hex file is used for flashing
diff --git a/boards/slstk3401a/Makefile.include b/boards/slstk3401a/Makefile.include
index b6a443535b..52633b1c80 100644
--- a/boards/slstk3401a/Makefile.include
+++ b/boards/slstk3401a/Makefile.include
@@ -6,7 +6,7 @@ PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.usbmodem*)))
 include $(RIOTMAKE)/tools/serial.inc.mk
 
 # setup JLink for flashing
-export JLINK_PRE_FLASH = r
+JLINK_PRE_FLASH = r
 
 # include board common
 include $(RIOTBOARD)/common/silabs/Makefile.include
diff --git a/boards/slstk3402a/Makefile.include b/boards/slstk3402a/Makefile.include
index b6a443535b..52633b1c80 100644
--- a/boards/slstk3402a/Makefile.include
+++ b/boards/slstk3402a/Makefile.include
@@ -6,7 +6,7 @@ PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.usbmodem*)))
 include $(RIOTMAKE)/tools/serial.inc.mk
 
 # setup JLink for flashing
-export JLINK_PRE_FLASH = r
+JLINK_PRE_FLASH = r
 
 # include board common
 include $(RIOTBOARD)/common/silabs/Makefile.include
diff --git a/boards/sltb001a/Makefile.include b/boards/sltb001a/Makefile.include
index 4124f8b61f..49293f93e7 100644
--- a/boards/sltb001a/Makefile.include
+++ b/boards/sltb001a/Makefile.include
@@ -7,7 +7,7 @@ include $(RIOTMAKE)/tools/serial.inc.mk
 
 # setup JLink for flashing
 JLINK_DEVICE = EFR32MG1PxxxF256
-export JLINK_PRE_FLASH = r
+JLINK_PRE_FLASH = r
 
 # include board common
 include $(RIOTBOARD)/common/silabs/Makefile.include