diff --git a/boards/calliope-mini/Makefile.include b/boards/calliope-mini/Makefile.include
index 35575ba53e..a7deba75d0 100644
--- a/boards/calliope-mini/Makefile.include
+++ b/boards/calliope-mini/Makefile.include
@@ -10,12 +10,12 @@ PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.usbmodem*)))
 PROGRAMMER ?= fscopy
 
 ifeq (fscopy,$(PROGRAMMER))
-  export FFLAGS = $(HEXFILE)
-  export DEBUGGER_FLAGS =
+  FFLAGS = $(HEXFILE)
+  DEBUGGER_FLAGS =
 
-  export FLASHER = $(RIOTBOARD)/$(BOARD)/dist/flash.sh
-  export DEBUGGER =
-  export DEBUGSERVER =
+  FLASHER = $(RIOTBOARD)/$(BOARD)/dist/flash.sh
+  DEBUGGER =
+  DEBUGSERVER =
 else ifeq (openocd,$(PROGRAMMER))
   DEBUG_ADAPTER = dap
 else ifeq (pyocd,$(PROGRAMMER))
diff --git a/boards/cc2538dk/Makefile.include b/boards/cc2538dk/Makefile.include
index 58e495ad87..91b36cbcc5 100644
--- a/boards/cc2538dk/Makefile.include
+++ b/boards/cc2538dk/Makefile.include
@@ -15,24 +15,24 @@ include $(RIOTMAKE)/tools/serial.inc.mk
 include $(RIOTMAKE)/tools/renode.inc.mk
 
 # debugger config
-export DEBUGGER = $(RIOTBOARD)/$(BOARD)/dist/debug.sh
-export DEBUGSERVER = JLinkGDBServer -device CC2538SF53
-export RESET = $(RIOTBOARD)/$(BOARD)/dist/reset.sh
+DEBUGGER = $(RIOTBOARD)/$(BOARD)/dist/debug.sh
+DEBUGSERVER = JLinkGDBServer -device CC2538SF53
+RESET = $(RIOTBOARD)/$(BOARD)/dist/reset.sh
 
 # Define the flash-tool and default port:
 export PROGRAMMER ?= cc2538-bsl
 
 ifeq ($(PROGRAMMER),cc2538-bsl)
-  export FLASHER = $(RIOTTOOLS)/cc2538-bsl/cc2538-bsl.py
-  export FFLAGS  = -p "$(PORT)" -e -w -v $(FLASHFILE)
+  FLASHER = $(RIOTTOOLS)/cc2538-bsl/cc2538-bsl.py
+  FFLAGS  = -p "$(PORT)" -e -w -v $(FLASHFILE)
 else ifeq ($(PROGRAMMER),jlink)
-  export FLASHER = $(RIOTBOARD)/$(BOARD)/dist/flash.sh
-  export FFLAGS  = $(BINDIR) $(FLASHFILE)
+  FLASHER = $(RIOTBOARD)/$(BOARD)/dist/flash.sh
+  FFLAGS  = $(BINDIR) $(FLASHFILE)
 endif
 
 OFLAGS = --gap-fill 0xff
 FLASHFILE ?= $(BINFILE)
-export DEBUGGER_FLAGS = $(BINDIR) $(ELFFILE)
-export RESET_FLAGS = $(BINDIR)
+DEBUGGER_FLAGS = $(BINDIR) $(ELFFILE)
+RESET_FLAGS = $(BINDIR)
 
 export OBJDUMPFLAGS += --disassemble --source --disassembler-options=force-thumb
diff --git a/boards/chronos/Makefile.include b/boards/chronos/Makefile.include
index 12321d761c..c13f7c5b8f 100644
--- a/boards/chronos/Makefile.include
+++ b/boards/chronos/Makefile.include
@@ -3,8 +3,8 @@ export CPU = cc430
 export CPU_MODEL = cc430f6137
 
 # flasher configuration
-export FLASHER = mspdebug
-export FFLAGS = rf2500 "prog $(HEXFILE)"
+FLASHER = mspdebug
+FFLAGS = rf2500 "prog $(HEXFILE)"
 
 INCLUDES += -I$(RIOTBOARD)/$(BOARD)/drivers/include
 
diff --git a/boards/common/esp32/Makefile.include b/boards/common/esp32/Makefile.include
index 2ce4a3dbea..0fb3fb3c25 100644
--- a/boards/common/esp32/Makefile.include
+++ b/boards/common/esp32/Makefile.include
@@ -8,4 +8,4 @@ PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.SLAB_USBtoUART*)))
 include $(RIOTMAKE)/tools/serial.inc.mk
 
 # reset tool configuration
-export RESET = esptool.py --before default_reset run
+RESET = esptool.py --before default_reset run
diff --git a/boards/common/esp8266/Makefile.include b/boards/common/esp8266/Makefile.include
index 5460a7fd32..4c60974b9a 100644
--- a/boards/common/esp8266/Makefile.include
+++ b/boards/common/esp8266/Makefile.include
@@ -8,4 +8,4 @@ PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.SLAB_USBtoUART*)))
 include $(RIOTMAKE)/tools/serial.inc.mk
 
 # reset tool configuration
-export RESET = esptool.py --before default_reset run
+RESET = esptool.py --before default_reset run
diff --git a/boards/common/msb-430/Makefile.include b/boards/common/msb-430/Makefile.include
index 5c054c4c66..58be9005a8 100644
--- a/boards/common/msb-430/Makefile.include
+++ b/boards/common/msb-430/Makefile.include
@@ -10,18 +10,18 @@ include $(RIOTMAKE)/tools/serial.inc.mk
 
 # setup flash tool
 export PROGRAMMER ?= olimex
-export MSPDEBUGFLAGS += -j $(PROGRAMMER)
+MSPDEBUGFLAGS += -j $(PROGRAMMER)
 ifeq ($(strip $(PROGRAMMER)),uif)
-  export MSPDEBUGFLAGS += -d $(PORT)
+  MSPDEBUGFLAGS += -d $(PORT)
 endif
-export FLASHER ?= mspdebug
-export FFLAGS = $(MSPDEBUGFLAGS) "prog $(HEXFILE)"
+FLASHER ?= mspdebug
+FFLAGS = $(MSPDEBUGFLAGS) "prog $(HEXFILE)"
 
 # setup debugger
-export DEBUGSERVER = $(FLASHER)
-export DEBUGSERVER_FLAGS = $(MSPDEBUGFLAGS) gdb
-export DEBUGGER = $(PREFIX)gdb
-export DEBUGGER_FLAGS = --tui --ex="target remote localhost:2000" --ex "monitor reset halt" --ex load -ex "monitor reset halt"  $(ELFFILE)
+DEBUGSERVER = $(FLASHER)
+DEBUGSERVER_FLAGS = $(MSPDEBUGFLAGS) gdb
+DEBUGGER = $(PREFIX)gdb
+DEBUGGER_FLAGS = --tui --ex="target remote localhost:2000" --ex "monitor reset halt" --ex load -ex "monitor reset halt"  $(ELFFILE)
 
 # export common msb-430 includes
 export INCLUDES += -I$(RIOTBOARD)/common/msb-430/include
diff --git a/boards/common/remote/Makefile.include b/boards/common/remote/Makefile.include
index aeccff4ca8..baa8250b4c 100644
--- a/boards/common/remote/Makefile.include
+++ b/boards/common/remote/Makefile.include
@@ -12,21 +12,21 @@ ifeq ($(PROGRAMMER),cc2538-bsl)
   else ifeq ($(OS),Darwin)
     PORT_BSL ?= $(PORT_DARWIN)
   endif
-  export RESET = $(RIOTTOOLS)/cc2538-bsl/cc2538-bsl.py -p "$(PORT_BSL)"
-  export FLASHER = $(RIOTTOOLS)/cc2538-bsl/cc2538-bsl.py
-  export FFLAGS  = -p "$(PORT_BSL)" -e -w -v -b 115200 $(FLASHFILE)
+  RESET = $(RIOTTOOLS)/cc2538-bsl/cc2538-bsl.py -p "$(PORT_BSL)"
+  FLASHER = $(RIOTTOOLS)/cc2538-bsl/cc2538-bsl.py
+  FFLAGS  = -p "$(PORT_BSL)" -e -w -v -b 115200 $(FLASHFILE)
 else ifeq ($(PROGRAMMER),jlink)
-  export FLASHER = $(RIOTBOARD)/common/remote/dist/flash.sh
-  export FFLAGS  = $(BINDIR) $(FLASHFILE)
-  export DEBUGGER = $(RIOTBOARD)/common/remote/dist/debug.sh
-  export DEBUGSERVER = JLinkGDBServer -device CC2538SF53
-  export RESET = $(RIOTBOARD)/common/remote/dist/reset.sh
-  export RESET_FLAGS = $(BINDIR)
+  FLASHER = $(RIOTBOARD)/common/remote/dist/flash.sh
+  FFLAGS  = $(BINDIR) $(FLASHFILE)
+  DEBUGGER = $(RIOTBOARD)/common/remote/dist/debug.sh
+  DEBUGSERVER = JLinkGDBServer -device CC2538SF53
+  RESET = $(RIOTBOARD)/common/remote/dist/reset.sh
+  RESET_FLAGS = $(BINDIR)
 endif
 
 OFLAGS = --gap-fill 0xff
 FLASHFILE ?= $(BINFILE)
-export DEBUGGER_FLAGS = $(BINDIR) $(ELFFILE)
+DEBUGGER_FLAGS = $(BINDIR) $(ELFFILE)
 export OBJDUMPFLAGS += --disassemble --source --disassembler-options=force-thumb
 
 # include common remote includes
diff --git a/boards/common/stm32f103c8/Makefile.include b/boards/common/stm32f103c8/Makefile.include
index 40997dc0ce..120700b236 100644
--- a/boards/common/stm32f103c8/Makefile.include
+++ b/boards/common/stm32f103c8/Makefile.include
@@ -23,14 +23,14 @@ include $(RIOTMAKE)/tools/serial.inc.mk
 # (ground) GPIO B1.
 ifeq ($(PROGRAMMER),dfu-util)
   export ROM_OFFSET ?= 0x2000 # Skip the space needed by the embedded bootloader
-  export FLASHER = dfu-util
-  export DEBUGGER = # no debugger
-  export RESET = # dfu-util has no support for resetting the device
+  FLASHER = dfu-util
+  DEBUGGER = # no debugger
+  RESET = # dfu-util has no support for resetting the device
 
   HEXFILE = $(BINFILE)
-  export FFLAGS = -d 1eaf:0003 -a 2 -D "$(HEXFILE)"
+  FFLAGS = -d 1eaf:0003 -a 2 -D "$(HEXFILE)"
   # for older bootloader versions use this:
-  #export FFLAGS = -d 1d50:6017 -s 0x08002000:leave -D "$(HEXFILE)"
+  # FFLAGS = -d 1d50:6017 -s 0x08002000:leave -D "$(HEXFILE)"
 else
 
   # this board uses openocd by default
diff --git a/boards/common/wsn430/Makefile.include b/boards/common/wsn430/Makefile.include
index 8987fe0958..9853cc8cf0 100644
--- a/boards/common/wsn430/Makefile.include
+++ b/boards/common/wsn430/Makefile.include
@@ -13,8 +13,8 @@ PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.SLAB_USBtoUART*)))
 include $(RIOTMAKE)/tools/serial.inc.mk
 
 # configure the flash tool
-export FLASHER = mspdebug
-export FFLAGS = -d $(PORT) -j uif "prog $(HEXFILE)"
+FLASHER = mspdebug
+FFLAGS = -d $(PORT) -j uif "prog $(HEXFILE)"
 
 # Use the HEXFILE when using iot-lab.single.inc.mk
 IOTLAB_FLASHFILE = $(HEXFILE)
diff --git a/boards/f4vi1/Makefile.include b/boards/f4vi1/Makefile.include
index 4ac58f2318..8ac44da078 100644
--- a/boards/f4vi1/Makefile.include
+++ b/boards/f4vi1/Makefile.include
@@ -13,11 +13,11 @@ PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.SLAB_USBtoUART*)))
 include $(RIOTMAKE)/tools/serial.inc.mk
 
 # st-flash
-export FLASHER = st-flash
-export DEBUGGER = $(RIOTBOARD)/$(BOARD)/dist/debug.sh
-export DEBUGSERVER = st-util
+FLASHER = st-flash
+DEBUGGER = $(RIOTBOARD)/$(BOARD)/dist/debug.sh
+DEBUGSERVER = st-util
 
 # define st-flash parameters
 HEXFILE = $(BINFILE)
-export FFLAGS = write $(HEXFILE) 0x8000000
-export DEBUGGER_FLAGS = $(RIOTBOARD)/$(BOARD)/dist/gdb.conf $(ELFFILE)
+FFLAGS = write $(HEXFILE) 0x8000000
+DEBUGGER_FLAGS = $(RIOTBOARD)/$(BOARD)/dist/gdb.conf $(ELFFILE)
diff --git a/boards/hifive1/Makefile.include b/boards/hifive1/Makefile.include
index a3abd6fe0d..258cc562e9 100644
--- a/boards/hifive1/Makefile.include
+++ b/boards/hifive1/Makefile.include
@@ -17,4 +17,4 @@ export OPENOCD_CMD_RESET_RUN=-c _reset
 include $(RIOTMAKE)/tools/openocd.inc.mk
 
 # use our own openocd script to flash since HiFive1 has reset problems.
-export FLASHER = $(RIOTBASE)/boards/hifive1/dist/flasher.sh
+FLASHER = $(RIOTBASE)/boards/hifive1/dist/flasher.sh
diff --git a/boards/mbed_lpc1768/Makefile.include b/boards/mbed_lpc1768/Makefile.include
index e5511e48d7..41c33bcd87 100644
--- a/boards/mbed_lpc1768/Makefile.include
+++ b/boards/mbed_lpc1768/Makefile.include
@@ -1,13 +1,13 @@
 # define the cpu used by the mbed_lpx1768 board
 export CPU = lpc1768
 
-export FLASHER = $(RIOTBOARD)/$(BOARD)/dist/flash.sh
-export DEBUGGER =
-export DEBUGSERVER =
+FLASHER = $(RIOTBOARD)/$(BOARD)/dist/flash.sh
+DEBUGGER =
+DEBUGSERVER =
 
 HEXFILE = $(BINFILE)
-export FFLAGS = $(HEXFILE)
-export DEBUGGER_FLAGS =
+FFLAGS = $(HEXFILE)
+DEBUGGER_FLAGS =
 
 # define the default port depending on the host OS
 PORT_LINUX ?= /dev/ttyACM0
diff --git a/boards/microbit/Makefile.include b/boards/microbit/Makefile.include
index 3436b5f801..496edb3d1b 100644
--- a/boards/microbit/Makefile.include
+++ b/boards/microbit/Makefile.include
@@ -10,12 +10,12 @@ PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.SLAB_USBtoUART*)))
 PROGRAMMER ?= fscopy
 
 ifeq (fscopy,$(PROGRAMMER))
-  export FFLAGS = $(HEXFILE)
-  export DEBUGGER_FLAGS =
+  FFLAGS = $(HEXFILE)
+  DEBUGGER_FLAGS =
 
-  export FLASHER = $(RIOTBOARD)/$(BOARD)/dist/flash.sh
-  export DEBUGGER =
-  export DEBUGSERVER =
+  FLASHER = $(RIOTBOARD)/$(BOARD)/dist/flash.sh
+  DEBUGGER =
+  DEBUGSERVER =
 else ifeq (openocd,$(PROGRAMMER))
   # this board uses a daplink adapter by default
   DEBUG_ADAPTER = dap
diff --git a/boards/native/Makefile.include b/boards/native/Makefile.include
index 91b4c84b1f..9ee94c3eb3 100644
--- a/boards/native/Makefile.include
+++ b/boards/native/Makefile.include
@@ -35,13 +35,13 @@ else
 endif
 
 ifeq ($(shell uname -s),Darwin)
-  export DEBUGGER ?= lldb
+  DEBUGGER ?= lldb
 else
-  export DEBUGGER ?= gdb
+  DEBUGGER ?= gdb
 endif
 
 TERMPROG ?= $(ELFFILE)
-export FLASHER = true
+FLASHER = true
 export VALGRIND ?= valgrind
 export CGANNOTATE ?= cg_annotate
 export GPROF ?= gprof
@@ -104,9 +104,9 @@ TERMFLAGS := $(PORT) $(TERMFLAGS)
 
 export ASFLAGS =
 ifeq ($(shell basename $(DEBUGGER)),lldb)
-  export DEBUGGER_FLAGS = -- $(ELFFILE) $(TERMFLAGS)
+  DEBUGGER_FLAGS = -- $(ELFFILE) $(TERMFLAGS)
 else
-  export DEBUGGER_FLAGS = -q --args $(ELFFILE) $(TERMFLAGS)
+  DEBUGGER_FLAGS = -q --args $(ELFFILE) $(TERMFLAGS)
 endif
 term-valgrind: export VALGRIND_FLAGS ?= \
 	--leak-check=full \
diff --git a/boards/nz32-sc151/Makefile.include b/boards/nz32-sc151/Makefile.include
index ad09aecc57..2e780acaee 100644
--- a/boards/nz32-sc151/Makefile.include
+++ b/boards/nz32-sc151/Makefile.include
@@ -9,12 +9,12 @@ PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.SLAB_USBtoUART*)))
 # set the default id
 export ID ?= 0483:df11
 
-export FLASHER = dfu-util
-export DEBUGGER = # dfu-util has no debugger
-export RESET = # dfu-util has no support for resetting the device
+FLASHER = dfu-util
+DEBUGGER = # dfu-util has no debugger
+RESET = # dfu-util has no support for resetting the device
 
 HEXFILE = $(BINFILE)
-export FFLAGS = -d $(ID) -a 0 -s 0x08000000:leave -D "$(HEXFILE)"
+FFLAGS = -d $(ID) -a 0 -s 0x08000000:leave -D "$(HEXFILE)"
 
 # setup serial terminal
 include $(RIOTMAKE)/tools/serial.inc.mk
diff --git a/boards/opencm904/Makefile.include b/boards/opencm904/Makefile.include
index 8ce69924a1..3f04b4aec5 100644
--- a/boards/opencm904/Makefile.include
+++ b/boards/opencm904/Makefile.include
@@ -3,13 +3,13 @@ export CPU = stm32f1
 export CPU_MODEL = stm32f103cb
 
 # custom flasher to use with the bootloader
-export FLASHER = $(RIOTBOARD)/$(BOARD)/dist/robotis-loader.py
-export DEBUGGER =
-export DEBUGSERVER =
+FLASHER = $(RIOTBOARD)/$(BOARD)/dist/robotis-loader.py
+DEBUGGER =
+DEBUGSERVER =
 
 HEXFILE = $(BINFILE)
-export FFLAGS = $(PORT) $(HEXFILE)
-export DEBUGGER_FLAGS =
+FFLAGS = $(PORT) $(HEXFILE)
+DEBUGGER_FLAGS =
 
 # define the default port depending on the host OS
 PORT_LINUX ?= /dev/ttyACM0
diff --git a/boards/openmote-b/Makefile.include b/boards/openmote-b/Makefile.include
index 43124605aa..49978e45ce 100644
--- a/boards/openmote-b/Makefile.include
+++ b/boards/openmote-b/Makefile.include
@@ -16,19 +16,19 @@ ifeq ($(PROGRAMMER),cc2538-bsl)
   else ifeq ($(OS),Darwin)
     PORT_BSL ?= $(PORT_DARWIN)
   endif
-  export FLASHER = $(RIOTBASE)/dist/tools/cc2538-bsl/cc2538-bsl.py
-  export FFLAGS  = -p "$(PORT_BSL)" --bootloader-invert-lines -e -w -v -b 460800 $(FLASHFILE)
+  FLASHER = $(RIOTBASE)/dist/tools/cc2538-bsl/cc2538-bsl.py
+  FFLAGS  = -p "$(PORT_BSL)" --bootloader-invert-lines -e -w -v -b 460800 $(FLASHFILE)
 else ifeq ($(PROGRAMMER),jlink)
-  export FLASHER = $(RIOTBOARD)/$(BOARD)/dist/flash.sh
-  export FFLAGS  = $(BINDIR) $(FLASHFILE)
-  export DEBUGGER = $(RIOTBOARD)/$(BOARD)/dist/debug.sh
-  export DEBUGSERVER = JLinkGDBServer -device CC2538SF53
-  export RESET = $(RIOTBOARD)/$(BOARD)/dist/reset.sh
+  FLASHER = $(RIOTBOARD)/$(BOARD)/dist/flash.sh
+  FFLAGS  = $(BINDIR) $(FLASHFILE)
+  DEBUGGER = $(RIOTBOARD)/$(BOARD)/dist/debug.sh
+  DEBUGSERVER = JLinkGDBServer -device CC2538SF53
+  RESET = $(RIOTBOARD)/$(BOARD)/dist/reset.sh
 endif
 
 FLASHFILE ?= $(BINFILE)
-export DEBUGGER_FLAGS = $(BINDIR) $(ELFFILE)
-export RESET_FLAGS = $(BINDIR)
+DEBUGGER_FLAGS = $(BINDIR) $(ELFFILE)
+RESET_FLAGS = $(BINDIR)
 export OBJDUMPFLAGS += --disassemble --source --disassembler-options=force-thumb
 
 # setup serial terminal
diff --git a/boards/openmote-cc2538/Makefile.include b/boards/openmote-cc2538/Makefile.include
index 5c7c30b6f0..d77f06b787 100644
--- a/boards/openmote-cc2538/Makefile.include
+++ b/boards/openmote-cc2538/Makefile.include
@@ -18,8 +18,8 @@ ifeq ($(PROGRAMMER),jlink)
   include $(RIOTMAKE)/tools/jlink.inc.mk
 else
   FLASHFILE ?= $(BINFILE)
-  export FLASHER = $(RIOTTOOLS)/cc2538-bsl/cc2538-bsl.py
-  export FFLAGS  = -p "$(PORT)" -e -w -v -b 460800 $(FLASHFILE)
+  FLASHER = $(RIOTTOOLS)/cc2538-bsl/cc2538-bsl.py
+  FFLAGS  = -p "$(PORT)" -e -w -v -b 460800 $(FLASHFILE)
 endif
 
 # setup serial terminal
diff --git a/boards/spark-core/Makefile.include b/boards/spark-core/Makefile.include
index cd71cdea80..6203e36a80 100644
--- a/boards/spark-core/Makefile.include
+++ b/boards/spark-core/Makefile.include
@@ -7,12 +7,12 @@ PORT_LINUX ?= /dev/ttyUSB0
 PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.SLAB_USBtoUART*)))
 include $(RIOTMAKE)/tools/serial.inc.mk
 
-export FLASHER = dfu-util
-export DEBUGGER = # spark core has no debugger
-export RESET = # dfu-util has no support for resetting the device
+FLASHER = dfu-util
+DEBUGGER = # spark core has no debugger
+RESET = # dfu-util has no support for resetting the device
 
 HEXFILE = $(BINFILE)
-export FFLAGS = -d 1d50:607f -a 0 -s 0x08005000:leave -D "$(HEXFILE)"
+FFLAGS = -d 1d50:607f -a 0 -s 0x08005000:leave -D "$(HEXFILE)"
 
 # Skip the space needed by the embedded bootloader
 export ROM_OFFSET ?= 0x5000
diff --git a/boards/telosb/Makefile.include b/boards/telosb/Makefile.include
index 1133e7fd73..f3a088913f 100644
--- a/boards/telosb/Makefile.include
+++ b/boards/telosb/Makefile.include
@@ -10,5 +10,5 @@ export BAUD ?= 9600
 include $(RIOTMAKE)/tools/serial.inc.mk
 
 # flash tool configuration
-export FLASHER = $(RIOTTOOLS)/goodfet/goodfet.bsl
-export FFLAGS = --telosb -c $(PORT) -r -e -I -p $(HEXFILE)
+FLASHER = $(RIOTTOOLS)/goodfet/goodfet.bsl
+FFLAGS = --telosb -c $(PORT) -r -e -I -p $(HEXFILE)
diff --git a/boards/z1/Makefile.include b/boards/z1/Makefile.include
index 2f64e0af73..7d99332157 100644
--- a/boards/z1/Makefile.include
+++ b/boards/z1/Makefile.include
@@ -9,5 +9,5 @@ PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.SLAB_USBtoUART*)))
 include $(RIOTMAKE)/tools/serial.inc.mk
 
 # setup flash tool
-export FLASHER = $(RIOTTOOLS)/goodfet/goodfet.bsl
-export FFLAGS = --z1 -I -c $(PORT) -r -e -p $(HEXFILE)
+FLASHER = $(RIOTTOOLS)/goodfet/goodfet.bsl
+FFLAGS = --z1 -I -c $(PORT) -r -e -p $(HEXFILE)
diff --git a/cpu/esp32/Makefile.include b/cpu/esp32/Makefile.include
index 79beae95be..2194541f16 100644
--- a/cpu/esp32/Makefile.include
+++ b/cpu/esp32/Makefile.include
@@ -145,40 +145,40 @@ LINKFLAGS += -Wl,--warn-unresolved-symbols
 FLASH_MODE ?= dout  # FIX configuration, DO NOT CHANGE
 FLASH_FREQ  = 40m   # FIX configuration, DO NOT CHANGE
 FLASH_SIZE ?= 2MB
-export PREFLASHER = $(ESPTOOL)
-export PREFFLAGS  = --chip esp32 elf2image
-export PREFFLAGS += -fm $(FLASH_MODE) -fs $(FLASH_SIZE) -ff $(FLASH_FREQ)
-export PREFFLAGS += -o $(ELFFILE).bin $(ELFFILE);
-export PREFFLAGS += echo "" > $(BINDIR)/partitions.csv;
-export PREFFLAGS += echo "nvs, data, nvs, 0x9000, 0x6000" >> $(BINDIR)/partitions.csv;
-export PREFFLAGS += echo "phy_init, data, phy, 0xf000, 0x1000" >> $(BINDIR)/partitions.csv;
-export PREFFLAGS += echo -n "factory, app, factory, 0x10000, " >> $(BINDIR)/partitions.csv;
-export PREFFLAGS += ls -l $(ELFFILE).bin | awk '{ print $$5 }' >> $(BINDIR)/partitions.csv;
+PREFLASHER = $(ESPTOOL)
+PREFFLAGS  = --chip esp32 elf2image
+PREFFLAGS += -fm $(FLASH_MODE) -fs $(FLASH_SIZE) -ff $(FLASH_FREQ)
+PREFFLAGS += -o $(ELFFILE).bin $(ELFFILE);
+PREFFLAGS += echo "" > $(BINDIR)/partitions.csv;
+PREFFLAGS += echo "nvs, data, nvs, 0x9000, 0x6000" >> $(BINDIR)/partitions.csv;
+PREFFLAGS += echo "phy_init, data, phy, 0xf000, 0x1000" >> $(BINDIR)/partitions.csv;
+PREFFLAGS += echo -n "factory, app, factory, 0x10000, " >> $(BINDIR)/partitions.csv;
+PREFFLAGS += ls -l $(ELFFILE).bin | awk '{ print $$5 }' >> $(BINDIR)/partitions.csv;
 
-export PREFFLAGS += python $(RIOTCPU)/$(CPU)/gen_esp32part.py --disable-sha256sum
-export PREFFLAGS += --verify $(BINDIR)/partitions.csv $(BINDIR)/partitions.bin
-export FLASHDEPS  = preflash
+PREFFLAGS += python $(RIOTCPU)/$(CPU)/gen_esp32part.py --disable-sha256sum
+PREFFLAGS += --verify $(BINDIR)/partitions.csv $(BINDIR)/partitions.bin
+FLASHDEPS  = preflash
 
 # flasher configuration
 ifeq ($(QEMU), 1)
-    export FLASHER = dd
-    export FFLAGS += if=/dev/zero bs=1M count=4  | tr "\\000" "\\377" > tmp.bin && cat tmp.bin |
-    export FFLAGS += head -c $$((0x1000)) |
-    export FFLAGS += cat - $(RIOTCPU)/$(CPU)/bin/bootloader.bin tmp.bin |
-    export FFLAGS += head -c $$((0x8000)) |
-    export FFLAGS += cat - $(BINDIR)/partitions.bin tmp.bin |
-    export FFLAGS += head -c $$((0x10000)) |
-    export FFLAGS += cat - $(ELFFILE).bin tmp.bin |
-    export FFLAGS += head -c $$((0x400000)) > $(BINDIR)/esp32flash.bin && rm tmp.bin &&
-    export FFLAGS += cp $(RIOTCPU)/$(CPU)/bin/rom_0x3ff90000_0x00010000.bin $(BINDIR)/rom1.bin &&
-    export FFLAGS += cp $(RIOTCPU)/$(CPU)/bin/rom_0x40000000_0x000c2000.bin $(BINDIR)/rom.bin
+    FLASHER = dd
+    FFLAGS += if=/dev/zero bs=1M count=4  | tr "\\000" "\\377" > tmp.bin && cat tmp.bin |
+    FFLAGS += head -c $$((0x1000)) |
+    FFLAGS += cat - $(RIOTCPU)/$(CPU)/bin/bootloader.bin tmp.bin |
+    FFLAGS += head -c $$((0x8000)) |
+    FFLAGS += cat - $(BINDIR)/partitions.bin tmp.bin |
+    FFLAGS += head -c $$((0x10000)) |
+    FFLAGS += cat - $(ELFFILE).bin tmp.bin |
+    FFLAGS += head -c $$((0x400000)) > $(BINDIR)/esp32flash.bin && rm tmp.bin &&
+    FFLAGS += cp $(RIOTCPU)/$(CPU)/bin/rom_0x3ff90000_0x00010000.bin $(BINDIR)/rom1.bin &&
+    FFLAGS += cp $(RIOTCPU)/$(CPU)/bin/rom_0x40000000_0x000c2000.bin $(BINDIR)/rom.bin
 else
     export PROGRAMMER_SPEED ?= 460800
-    export FLASHER = $(ESPTOOL)
-    export FFLAGS += --chip esp32 -p $(PORT) -b $(PROGRAMMER_SPEED)
-    export FFLAGS += --before default_reset --after hard_reset write_flash
-    export FFLAGS += -z -fm $(FLASH_MODE) -fs detect -ff $(FLASH_FREQ)
-    export FFLAGS += 0x1000 $(RIOTCPU)/$(CPU)/bin/bootloader.bin
-    export FFLAGS += 0x8000 $(BINDIR)/partitions.bin
-    export FFLAGS += 0x10000 $(ELFFILE).bin
+    FLASHER = $(ESPTOOL)
+    FFLAGS += --chip esp32 -p $(PORT) -b $(PROGRAMMER_SPEED)
+    FFLAGS += --before default_reset --after hard_reset write_flash
+    FFLAGS += -z -fm $(FLASH_MODE) -fs detect -ff $(FLASH_FREQ)
+    FFLAGS += 0x1000 $(RIOTCPU)/$(CPU)/bin/bootloader.bin
+    FFLAGS += 0x8000 $(BINDIR)/partitions.bin
+    FFLAGS += 0x10000 $(ELFFILE).bin
 endif
diff --git a/cpu/esp8266/Makefile.include b/cpu/esp8266/Makefile.include
index e90a4eb6b5..01d2885d2c 100644
--- a/cpu/esp8266/Makefile.include
+++ b/cpu/esp8266/Makefile.include
@@ -131,22 +131,22 @@ LINKFLAGS += -Wl,--warn-unresolved-symbols
 
 # configure preflasher to convert .elf to .bin before flashing
 FLASH_SIZE = -fs 8m
-export PREFLASHER ?= esptool.py
-export PREFFLAGS  ?= elf2image $(FLASH_SIZE) $(ELFFILE)
-export FLASHDEPS  ?= preflash
+PREFLASHER ?= esptool.py
+PREFFLAGS  ?= elf2image $(FLASH_SIZE) $(ELFFILE)
+FLASHDEPS  ?= preflash
 
 # flasher configuration
 ifeq ($(QEMU), 1)
-    export FLASHER = cat
-    export FFLAGS += $(ELFFILE)-0x00000.bin /dev/zero | head -c $$((0x10000)) | cat -
-    export FFLAGS += $(ELFFILE)-0x10000.bin /dev/zero | head -c $$((0xfc000)) | cat -
-    export FFLAGS += $(RIOTCPU)/$(CPU)/bin/esp_init_data_default.bin > $(ELFFILE).bin
+    FLASHER = cat
+    FFLAGS += $(ELFFILE)-0x00000.bin /dev/zero | head -c $$((0x10000)) | cat -
+    FFLAGS += $(ELFFILE)-0x10000.bin /dev/zero | head -c $$((0xfc000)) | cat -
+    FFLAGS += $(RIOTCPU)/$(CPU)/bin/esp_init_data_default.bin > $(ELFFILE).bin
 else
     FLASH_MODE ?= dout
     export PROGRAMMER_SPEED ?= 460800
-    export FLASHER = esptool.py
-    export FFLAGS += -p $(PORT) -b $(PROGRAMMER_SPEED) write_flash
-    export FFLAGS += -fm $(FLASH_MODE)
-    export FFLAGS += 0 $(ELFFILE)-0x00000.bin
-    export FFLAGS += 0x10000 $(ELFFILE)-0x10000.bin; esptool.py -p $(PORT) run
+    FLASHER = esptool.py
+    FFLAGS += -p $(PORT) -b $(PROGRAMMER_SPEED) write_flash
+    FFLAGS += -fm $(FLASH_MODE)
+    FFLAGS += 0 $(ELFFILE)-0x00000.bin
+    FFLAGS += 0x10000 $(ELFFILE)-0x10000.bin; esptool.py -p $(PORT) run
 endif
diff --git a/dist/tools/buildsystem_sanity_check/check.sh b/dist/tools/buildsystem_sanity_check/check.sh
index 52f6c85fad..7704287551 100755
--- a/dist/tools/buildsystem_sanity_check/check.sh
+++ b/dist/tools/buildsystem_sanity_check/check.sh
@@ -50,6 +50,13 @@ check_not_parsing_features() {
 UNEXPORTED_VARIABLES=()
 UNEXPORTED_VARIABLES+=('FLASHFILE')
 UNEXPORTED_VARIABLES+=('TERMPROG' 'TERMFLAGS')
+UNEXPORTED_VARIABLES+=('FLASHER' 'FFLAGS')
+UNEXPORTED_VARIABLES+=('RESET' 'RESETFLAGS')
+UNEXPORTED_VARIABLES+=('DEBUGGER' 'DEBUGGER_FLAGS')
+UNEXPORTED_VARIABLES+=('DEBUGSERVER' 'DEBUGSERVER_FLAGS')
+UNEXPORTED_VARIABLES+=('PREFLASHER' 'PREFFLAGS' 'FLASHDEPS')
+
+EXPORTED_VARIABLES_ONLY_IN_VARS=()
 check_not_exporting_variables() {
     local patterns=()
     local pathspec=()
@@ -58,13 +65,22 @@ check_not_exporting_variables() {
         patterns+=(-e "export[[:blank:]]\+${variable}")
     done
 
-    pathspec+=('*')
+    git -C "${RIOTBASE}" grep "${patterns[@]}"
 
-    # Ignore `makefiles/vars.inc.mk` as it currently is the only place that
-    # should export common variables.
+    # Some variables may still be exported in 'makefiles/vars.inc.mk' as the
+    # only place that should export commont variables
+    pathspec+=('*')
     pathspec+=(':!makefiles/vars.inc.mk')
 
-    git -C "${RIOTBASE}" grep "${patterns[@]}" -- "${pathspec[@]}"
+    patterns=()
+    for variable in "${EXPORTED_VARIABLES_ONLY_IN_VARS[@]}"; do
+        patterns+=(-e "export[[:blank:]]\+${variable}")
+    done
+
+    # Only run if there are patterns, otherwise it matches everything
+    if [ ${#patterns[@]} -ne 0 ]; then
+        git -C "${RIOTBASE}" grep "${patterns[@]}" -- "${pathspec[@]}"
+    fi
 }
 
 
diff --git a/makefiles/tools/bossa.inc.mk b/makefiles/tools/bossa.inc.mk
index b98eee54da..b755a9053a 100644
--- a/makefiles/tools/bossa.inc.mk
+++ b/makefiles/tools/bossa.inc.mk
@@ -1,5 +1,5 @@
-export FLASHER ?= $(RIOTTOOLS)/bossa/bossac
-export FFLAGS  ?= -p $(PORT) -e -i -w -v -b -R $(HEXFILE)
+FLASHER ?= $(RIOTTOOLS)/bossa/bossac
+FFLAGS  ?= -p $(PORT) -e -i -w -v -b -R $(HEXFILE)
 
 HEXFILE = $(BINFILE)
 
diff --git a/makefiles/tools/jlink.inc.mk b/makefiles/tools/jlink.inc.mk
index 61abdd1290..b7f04be2fc 100644
--- a/makefiles/tools/jlink.inc.mk
+++ b/makefiles/tools/jlink.inc.mk
@@ -1,11 +1,11 @@
-export FLASHER = $(RIOTTOOLS)/jlink/jlink.sh
-export DEBUGGER = $(RIOTTOOLS)/jlink/jlink.sh
-export DEBUGSERVER = $(RIOTTOOLS)/jlink/jlink.sh
-export RESET = $(RIOTTOOLS)/jlink/jlink.sh
+FLASHER = $(RIOTTOOLS)/jlink/jlink.sh
+DEBUGGER = $(RIOTTOOLS)/jlink/jlink.sh
+DEBUGSERVER = $(RIOTTOOLS)/jlink/jlink.sh
+RESET = $(RIOTTOOLS)/jlink/jlink.sh
 
 FLASHFILE ?= $(BINFILE)
 
-export FFLAGS ?= flash $(FLASHFILE)
-export DEBUGGER_FLAGS ?= debug $(ELFFILE)
-export DEBUGSERVER_FLAGS ?= debug-server
-export RESET_FLAGS ?= reset
+FFLAGS ?= flash $(FLASHFILE)
+DEBUGGER_FLAGS ?= debug $(ELFFILE)
+DEBUGSERVER_FLAGS ?= debug-server
+RESET_FLAGS ?= reset
diff --git a/makefiles/tools/openocd.inc.mk b/makefiles/tools/openocd.inc.mk
index 74709c59e4..b478ab2711 100644
--- a/makefiles/tools/openocd.inc.mk
+++ b/makefiles/tools/openocd.inc.mk
@@ -1,13 +1,13 @@
-export FLASHER ?= $(RIOTTOOLS)/openocd/openocd.sh
-export DEBUGGER = $(RIOTTOOLS)/openocd/openocd.sh
-export DEBUGSERVER = $(RIOTTOOLS)/openocd/openocd.sh
-export RESET ?= $(RIOTTOOLS)/openocd/openocd.sh
+FLASHER ?= $(RIOTTOOLS)/openocd/openocd.sh
+DEBUGGER = $(RIOTTOOLS)/openocd/openocd.sh
+DEBUGSERVER = $(RIOTTOOLS)/openocd/openocd.sh
+RESET ?= $(RIOTTOOLS)/openocd/openocd.sh
 
 FLASHFILE ?= $(ELFFILE)
-export FFLAGS ?= flash $(FLASHFILE)
-export DEBUGGER_FLAGS ?= debug $(ELFFILE)
-export DEBUGSERVER_FLAGS ?= debug-server
-export RESET_FLAGS ?= reset
+FFLAGS ?= flash $(FLASHFILE)
+DEBUGGER_FLAGS ?= debug $(ELFFILE)
+DEBUGSERVER_FLAGS ?= debug-server
+RESET_FLAGS ?= reset
 
 ifneq (,$(DEBUG_ADAPTER))
   include $(RIOTMAKE)/tools/openocd-adapters/$(DEBUG_ADAPTER).inc.mk
diff --git a/makefiles/tools/pyocd.inc.mk b/makefiles/tools/pyocd.inc.mk
index 998a1eff1b..f8ba7c6547 100644
--- a/makefiles/tools/pyocd.inc.mk
+++ b/makefiles/tools/pyocd.inc.mk
@@ -1,10 +1,10 @@
-export FLASHER ?= $(RIOTBASE)/dist/tools/pyocd/pyocd.sh
-export DEBUGGER = $(RIOTBASE)/dist/tools/pyocd/pyocd.sh
-export DEBUGSERVER = $(RIOTBASE)/dist/tools/pyocd/pyocd.sh
-export RESET ?= $(RIOTBASE)/dist/tools/pyocd/pyocd.sh
+FLASHER ?= $(RIOTBASE)/dist/tools/pyocd/pyocd.sh
+DEBUGGER = $(RIOTBASE)/dist/tools/pyocd/pyocd.sh
+DEBUGSERVER = $(RIOTBASE)/dist/tools/pyocd/pyocd.sh
+RESET ?= $(RIOTBASE)/dist/tools/pyocd/pyocd.sh
 
 export OFLAGS ?= -O ihex
-export FFLAGS ?= flash $(HEXFILE)
-export DEBUGGER_FLAGS ?= debug $(ELFFILE)
-export DEBUGSERVER_FLAGS ?= debug-server
-export RESET_FLAGS ?= reset
+FFLAGS ?= flash $(HEXFILE)
+DEBUGGER_FLAGS ?= debug $(ELFFILE)
+DEBUGSERVER_FLAGS ?= debug-server
+RESET_FLAGS ?= reset
diff --git a/makefiles/tools/uniflash.inc.mk b/makefiles/tools/uniflash.inc.mk
index f2aebbd17c..91f315754c 100644
--- a/makefiles/tools/uniflash.inc.mk
+++ b/makefiles/tools/uniflash.inc.mk
@@ -4,27 +4,27 @@ FLASHFILE ?= $(ELFFILE)
 export UNIFLASH_PATH ?= "UNIFLASH_PATH unconfigured"
 # check which uniflash version is available, either 4.x or 3.x
 ifneq ("$(wildcard $(UNIFLASH_PATH)/dslite.sh)","")
-  export FLASHER ?= $(UNIFLASH_PATH)/dslite.sh
-  export FFLAGS  = --config $(RIOTBOARD)/$(BOARD)/dist/$(CPU_MODEL)_$(XDEBUGGER).ccxml $(FLASHFILE)
+  FLASHER ?= $(UNIFLASH_PATH)/dslite.sh
+  FFLAGS  = --config $(RIOTBOARD)/$(BOARD)/dist/$(CPU_MODEL)_$(XDEBUGGER).ccxml $(FLASHFILE)
   # configure uniflash for resetting target
   # xds110reset path changed in version UniFlash v4.4.0
   # Try to detect the newest one and fallback to only 'xds110reset'
   _XDS110RESET_4_0_4_3 ?= $(UNIFLASH_PATH)/simplelink/gen2/bin/xds110reset
   _XDS110RESET ?= $(UNIFLASH_PATH)/simplelink/imagecreator/bin/xds110reset
   XDS110RESET ?= $(firstword $(wildcard $(_XDS110RESET) $(_XDS110RESET_4_0_4_3)) xds110reset)
-  export RESET = $(XDS110RESET)
-  export RESET_FLAGS
+  RESET = $(XDS110RESET)
+  RESET_FLAGS
 else
-  export FLASHER = $(UNIFLASH_PATH)/uniflash.sh
-  export FFLAGS  = -ccxml $(RIOTBOARD)/$(BOARD)/dist/$(CPU_MODEL)_$(XDEBUGGER).ccxml -program $(FLASHFILE)
+  FLASHER = $(UNIFLASH_PATH)/uniflash.sh
+  FFLAGS  = -ccxml $(RIOTBOARD)/$(BOARD)/dist/$(CPU_MODEL)_$(XDEBUGGER).ccxml -program $(FLASHFILE)
   # configure uniflash for resetting target
-  export RESET = $(UNIFLASH_PATH)/uniflash.sh
-  export RESET_FLAGS = -ccxml $(RIOTBOARD)/$(BOARD)/dist/$(CPU_MODEL)_$(XDEBUGGER).ccxml -reset
+  RESET = $(UNIFLASH_PATH)/uniflash.sh
+  RESET_FLAGS = -ccxml $(RIOTBOARD)/$(BOARD)/dist/$(CPU_MODEL)_$(XDEBUGGER).ccxml -reset
 endif
 # configure the debug server
-export DEBUGSERVER = $(UNIFLASH_PATH)/ccs_base/common/uscif/gdb_agent_console
-export DEBUGSERVER_FLAGS = -p 3333 $(RIOTBOARD)/$(BOARD)/dist/$(CPU_MODEL)_$(XDEBUGGER).dat
+DEBUGSERVER = $(UNIFLASH_PATH)/ccs_base/common/uscif/gdb_agent_console
+DEBUGSERVER_FLAGS = -p 3333 $(RIOTBOARD)/$(BOARD)/dist/$(CPU_MODEL)_$(XDEBUGGER).dat
 
 # configure the debugging tool
-export DEBUGGER = $(PREFIX)gdb
-export DEBUGGER_FLAGS = -x $(RIOTBOARD)/$(BOARD)/dist/$(CPU_MODEL)_gdb.conf $(ELFFILE)
+DEBUGGER = $(PREFIX)gdb
+DEBUGGER_FLAGS = -x $(RIOTBOARD)/$(BOARD)/dist/$(CPU_MODEL)_gdb.conf $(ELFFILE)
diff --git a/makefiles/vars.inc.mk b/makefiles/vars.inc.mk
index bff4d74f52..f2c5ac9ed0 100644
--- a/makefiles/vars.inc.mk
+++ b/makefiles/vars.inc.mk
@@ -69,8 +69,8 @@ export WERROR                # Treat all compiler warnings as errors if set to 1
 
 export GITCACHE              # path to git-cache executable
 export GIT_CACHE_DIR         # path to git-cache cache directory
-export FLASHER               # The command to call on "make flash".
-export FFLAGS                # The parameters to supply to FLASHER.
+# FLASHER                    # The command to call on "make flash".
+# FFLAGS                     # The parameters to supply to FLASHER.
 export FLASH_ADDR            # Define an offset to flash code into ROM memory.
 # TERMPROG                   # The command to call on "make term".
 # TERMFLAGS                  # Additional parameters to supply to TERMPROG.
@@ -78,12 +78,12 @@ export PORT                  # The port to connect the TERMPROG to.
 export ELFFILE               # The unstripped result of the compilation.
 export HEXFILE               # The stripped result of the compilation.
 # FLASHFILE                  # The output file used for flashing (transition phase: only if defined)
-export DEBUGGER              # The command to call on "make debug", usually a script starting the GDB front-end.
-export DEBUGGER_FLAGS        # The parameters to supply to DEBUGGER.
-export DEBUGSERVER           # The command to call on "make debug-server", usually a script starting the GDB server.
-export DEBUGSERVER_FLAGS     # The parameters to supply to DEBUGSERVER.
-export RESET                 # The command to call on "make reset", this command resets/reboots the target.
-export RESET_FLAGS           # The parameters to supply to RESET.
+# DEBUGGER                   # The command to call on "make debug", usually a script starting the GDB front-end.
+# DEBUGGER_FLAGS             # The parameters to supply to DEBUGGER.
+# DEBUGSERVER                # The command to call on "make debug-server", usually a script starting the GDB server.
+# DEBUGSERVER_FLAGS          # The parameters to supply to DEBUGSERVER.
+# RESET                      # The command to call on "make reset", this command resets/reboots the target.
+# RESET_FLAGS                # The parameters to supply to RESET.
 
 export CCACHE_BASEDIR        # ccache basedir, allows multiple riot build
                              # directories to share a ccache directory