diff --git a/dist/Makefile b/dist/Makefile
index 9f1ec8720f..305b3b947f 100644
--- a/dist/Makefile
+++ b/dist/Makefile
@@ -41,7 +41,7 @@ QUIET ?= 1
 
 #DISABLE_MODULE += core_msg
 
-#export INCLUDES += -Iapplication_include
+#INCLUDES += -Iapplication_include
 
 # Specify custom dependencies for your application here ...
 # APPDEPS = app_data.h config.h
diff --git a/makefiles/arch/cortexm.inc.mk b/makefiles/arch/cortexm.inc.mk
index da254390f4..b55d5f4fa5 100644
--- a/makefiles/arch/cortexm.inc.mk
+++ b/makefiles/arch/cortexm.inc.mk
@@ -2,12 +2,12 @@
 export TARGET_ARCH ?= arm-none-eabi
 
 # define build specific options
-export CFLAGS_CPU   = -mcpu=$(MCPU) -mlittle-endian -mthumb $(CFLAGS_FPU)
+CFLAGS_CPU   = -mcpu=$(MCPU) -mlittle-endian -mthumb $(CFLAGS_FPU)
 
 ifneq (llvm,$(TOOLCHAIN))
 # Clang (observed with v3.7) does not understand  -mno-thumb-interwork, only add if
 # not building with LLVM
-export CFLAGS      += -mno-thumb-interwork
+CFLAGS      += -mno-thumb-interwork
 
 # work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85606
 ifneq (,$(filter cortex-m0%,$(CPU_ARCH)))
@@ -15,13 +15,13 @@ ifneq (,$(filter cortex-m0%,$(CPU_ARCH)))
 endif
 endif
 
-export CFLAGS_LINK  = -ffunction-sections -fdata-sections -fno-builtin -fshort-enums
-export CFLAGS_DBG  ?= -ggdb -g3
-export CFLAGS_OPT  ?= -Os
+CFLAGS_LINK  = -ffunction-sections -fdata-sections -fno-builtin -fshort-enums
+CFLAGS_DBG  ?= -ggdb -g3
+CFLAGS_OPT  ?= -Os
 
-export CFLAGS += $(CFLAGS_CPU) $(CFLAGS_LINK) $(CFLAGS_DBG) $(CFLAGS_OPT)
+CFLAGS += $(CFLAGS_CPU) $(CFLAGS_LINK) $(CFLAGS_DBG) $(CFLAGS_OPT)
 
-export ASFLAGS += $(CFLAGS_CPU) $(CFLAGS_DBG)
+ASFLAGS += $(CFLAGS_CPU) $(CFLAGS_DBG)
 export LINKFLAGS += -L$(RIOTCPU)/$(CPU)/ldscripts -L$(RIOTCPU)/cortexm_common/ldscripts
 export LINKER_SCRIPT ?= $(CPU_MODEL).ld
 export LINKFLAGS += -T$(LINKER_SCRIPT) -Wl,--fatal-warnings
@@ -81,24 +81,23 @@ endif
 endif
 endif
 
-# export the CPU model and architecture
 MODEL = $(shell echo $(CPU_MODEL) | tr 'a-z' 'A-Z')
-export CFLAGS += -DCPU_MODEL_$(MODEL)
+CFLAGS += -DCPU_MODEL_$(MODEL)
 ARCH = $(shell echo $(CPU_ARCH) | tr 'a-z-' 'A-Z_')
-export CFLAGS += -DCPU_ARCH_$(ARCH)
+CFLAGS += -DCPU_ARCH_$(ARCH)
 
 # set the compiler specific CPU and FPU options
 ifneq (,$(filter $(CPU_ARCH),cortex-m4f cortex-m7))
     ifneq (,$(filter cortexm_fpu,$(DISABLE_MODULE)))
-        export CFLAGS_FPU ?= -mfloat-abi=soft
+        CFLAGS_FPU ?= -mfloat-abi=soft
     else
         USEMODULE += cortexm_fpu
         # clang assumes there is an FPU
         ifneq (llvm,$(TOOLCHAIN))
             ifeq ($(CPU_ARCH),cortex-m7)
-                export CFLAGS_FPU ?= -mfloat-abi=hard -mfpu=fpv5-d16
+                CFLAGS_FPU ?= -mfloat-abi=hard -mfpu=fpv5-d16
             else
-                export CFLAGS_FPU ?= -mfloat-abi=hard -mfpu=fpv4-sp-d16
+                CFLAGS_FPU ?= -mfloat-abi=hard -mfpu=fpv4-sp-d16
             endif
         endif
     endif
@@ -116,19 +115,19 @@ endif
 ifneq (,$(filter cmsis-dsp,$(USEPKG)))
 # definition needed to use cmsis-dsp headers
 ifeq ($(CPU_ARCH),cortex-m0)
-export CFLAGS += -DARM_MATH_CM0
+CFLAGS += -DARM_MATH_CM0
 else ifeq ($(CPU_ARCH),cortex-m0plus)
-export CFLAGS += -DARM_MATH_CM0PLUS
+CFLAGS += -DARM_MATH_CM0PLUS
 else ifeq ($(CPU_ARCH),cortex-m3)
-export CFLAGS += -DARM_MATH_CM3
+CFLAGS += -DARM_MATH_CM3
 else ifeq ($(CPU_ARCH),cortex-m4)
-export CFLAGS += -DARM_MATH_CM4
+CFLAGS += -DARM_MATH_CM4
 else ifeq ($(CPU_ARCH),cortex-m4f)
-export CFLAGS += -DARM_MATH_CM4
+CFLAGS += -DARM_MATH_CM4
 else ifeq ($(CPU_ARCH),cortex-m7)
-export CFLAGS += -DARM_MATH_CM7
+CFLAGS += -DARM_MATH_CM7
 else ifeq ($(CPU_ARCH),cortex-m23)
-export CFLAGS += -DARM_MATH_CM23
+CFLAGS += -DARM_MATH_CM23
 endif
 endif
 
diff --git a/makefiles/arch/mips.inc.mk b/makefiles/arch/mips.inc.mk
index cda818cfe7..5ff6935539 100644
--- a/makefiles/arch/mips.inc.mk
+++ b/makefiles/arch/mips.inc.mk
@@ -33,34 +33,34 @@ endif
 # https://cygwin.com/git/gitweb.cgi?p=newlib-cygwin.git;a=commitdiff;h=81c17949f0419d1c4fee421c60987ea1149522ae
 # Otherwise we get an error about a missing declaration of strnlen in some parts.
 ifeq (, $(filter -std=%, $(CFLAGS)))
-  export CFLAGS += -std=gnu99
+  CFLAGS += -std=gnu99
 endif
-export CFLAGS_CPU   = -EL -mabi=$(ABI)
-export CFLAGS_LINK  = -ffunction-sections -fno-builtin -fshort-enums -fdata-sections
-export CFLAGS_DBG   = -g3
-export CFLAGS_OPT   = -Os
+CFLAGS_CPU   = -EL -mabi=$(ABI)
+CFLAGS_LINK  = -ffunction-sections -fno-builtin -fshort-enums -fdata-sections
+CFLAGS_DBG   = -g3
+CFLAGS_OPT   = -Os
 
-export CFLAGS += $(CFLAGS_CPU) $(CFLAGS_LINK) $(CFLAGS_OPT) $(CFLAGS_DBG)
+CFLAGS += $(CFLAGS_CPU) $(CFLAGS_LINK) $(CFLAGS_OPT) $(CFLAGS_DBG)
 
 ifeq ($(USE_HARD_FLOAT),1)
-    export CFLAGS += -mhard-float -DMIPS_HARD_FLOAT
+    CFLAGS += -mhard-float -DMIPS_HARD_FLOAT
 else
     #hard-float is the default so we must set soft-float
-    export CFLAGS += -msoft-float
+    CFLAGS += -msoft-float
     export LINKFLAGS += -msoft-float
 endif
 
 ifeq ($(USE_DSP),1)
-    export CFLAGS += -mdsp -DMIPS_DSP
+    CFLAGS += -mdsp -DMIPS_DSP
 endif
 
 ifeq ($(TOOLCHAIN),llvm)
 # The MIPS toolchain headers in assembly mode are not compatible with Clang
-export CCAS = $(PREFIX)gcc
-export CCASUWFLAGS += -target $(TARGET_ARCH)
+CCAS = $(PREFIX)gcc
+CCASUWFLAGS += -target $(TARGET_ARCH)
 endif
 
-export ASFLAGS += $(CFLAGS_CPU) $(CFLAGS_OPT) $(CFLAGS_DBG)
+ASFLAGS += $(CFLAGS_CPU) $(CFLAGS_OPT) $(CFLAGS_DBG)
 
 export LINKFLAGS += $(MIPS_HAL_LDFLAGS)
 export LINKFLAGS += -L$(RIOTCPU)/$(CPU)/ldscripts
diff --git a/makefiles/arch/msp430.inc.mk b/makefiles/arch/msp430.inc.mk
index 1ebe522be8..59be092b98 100644
--- a/makefiles/arch/msp430.inc.mk
+++ b/makefiles/arch/msp430.inc.mk
@@ -5,14 +5,12 @@ export TARGET_ARCH ?= msp430
 CFLAGS_CPU   = -mmcu=$(CPU_MODEL)
 # default std set to gnu99 of not overwritten by user
 ifeq (, $(filter -std=%, $(CFLAGS)))
-  export CFLAGS += -std=gnu99
+  CFLAGS += -std=gnu99
 endif
 CFLAGS_LINK  = -ffunction-sections -fdata-sections
 CFLAGS_DBG  ?= -gdwarf-2
 CFLAGS_OPT  ?= -Os
-# export compiler flags
-export CFLAGS += $(CFLAGS_CPU) $(CFLAGS_LINK) $(CFLAGS_DBG) $(CFLAGS_OPT)
-# export assmebly flags
-export ASFLAGS += $(CFLAGS_CPU) --defsym $(CPU_MODEL)=1 $(CFLAGS_DBG)
+CFLAGS += $(CFLAGS_CPU) $(CFLAGS_LINK) $(CFLAGS_DBG) $(CFLAGS_OPT)
+ASFLAGS += $(CFLAGS_CPU) --defsym $(CPU_MODEL)=1 $(CFLAGS_DBG)
 # export linker flags
 export LINKFLAGS += $(CFLAGS_CPU) $(CFLAGS_DBG) $(CFLAGS_OPT) -Wl,--gc-sections -static -lgcc
diff --git a/makefiles/arch/riscv.inc.mk b/makefiles/arch/riscv.inc.mk
index 549e3d87f3..5b1dfd1d1d 100644
--- a/makefiles/arch/riscv.inc.mk
+++ b/makefiles/arch/riscv.inc.mk
@@ -11,9 +11,7 @@ export LINKFLAGS += -L$(RIOTCPU)/$(CPU)/ldscripts
 export LINKER_SCRIPT ?= $(CPU_MODEL).ld
 export LINKFLAGS += -T$(LINKER_SCRIPT)
 
-# export compiler flags
-export CFLAGS += $(CFLAGS_CPU) $(CFLAGS_DBG) $(CFLAGS_OPT) $(CFLAGS_LINK)
-# export assmebly flags
-export ASFLAGS += $(CFLAGS_CPU) $(CFLAGS_DBG)
+CFLAGS += $(CFLAGS_CPU) $(CFLAGS_DBG) $(CFLAGS_OPT) $(CFLAGS_LINK)
+ASFLAGS += $(CFLAGS_CPU) $(CFLAGS_DBG)
 # export linker flags
 export LINKFLAGS += $(CFLAGS_CPU) $(CFLAGS_LINK) $(CFLAGS_DBG) $(CFLAGS_OPT) -Wl,--gc-sections -static -lgcc