diff --git a/bare-arm/Makefile b/bare-arm/Makefile
index 0e9f1f7c39e930e5ef7268b7db171e7b318f0f0f..ace508ebd8996bedfe9ee1f1def329e790b622db 100644
--- a/bare-arm/Makefile
+++ b/bare-arm/Makefile
@@ -8,8 +8,12 @@ include ../py/py.mk
 
 CROSS_COMPILE = arm-none-eabi-
 
+INC =  -I.
+INC += -I$(PY_SRC)
+INC += -I$(BUILD)/includes
+
 CFLAGS_CORTEX_M4 = -mthumb -mtune=cortex-m4 -mabi=aapcs-linux -mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -mfloat-abi=hard -fsingle-precision-constant -Wdouble-promotion
-CFLAGS = -I. -I$(PY_SRC) -Wall -Werror -ansi -std=gnu99 $(CFLAGS_CORTEX_M4) $(COPT)
+CFLAGS = $(INC) -Wall -Werror -ansi -std=gnu99 $(CFLAGS_CORTEX_M4) $(COPT)
 
 #Debugging/Optimization
 ifeq ($(DEBUG), 1)
diff --git a/py/mkrules.mk b/py/mkrules.mk
index 08ba8fc416e80c081311509a9f1ca1040d2a5c6f..63a98a8ec6af520dcb6c7f29ff8d9d677fabd0f5 100644
--- a/py/mkrules.mk
+++ b/py/mkrules.mk
@@ -59,10 +59,16 @@ $(BUILD)/%.pp: %.c
 # object directories (but only for existance), and the object directories
 # will be created if they don't exist.
 OBJ_DIRS = $(sort $(dir $(OBJ)))
-$(OBJ): $(PY_BUILD)/qstrdefs.generated.h | $(OBJ_DIRS)
+$(OBJ): $(HEADER_PY_BUILD)/qstrdefs.generated.h | $(OBJ_DIRS)
 $(OBJ_DIRS):
 	$(MKDIR) -p $@
 
+$(HEADER_BUILD):
+	$(MKDIR) -p $@
+
+$(HEADER_PY_BUILD):
+	$(MKDIR) -p $@
+
 ifneq ($(PROG),)
 # Build a standalone executable (unix and unix-cpy do this)
 
diff --git a/py/py.mk b/py/py.mk
index 1bd536718e99505256165c4d7a203463d244c824..01a5fd1c2bb0d850e551ea301051271ed5e9aed8 100644
--- a/py/py.mk
+++ b/py/py.mk
@@ -1,8 +1,13 @@
 # where py object files go (they have a name prefix to prevent filename clashes)
 PY_BUILD = $(BUILD)/py
 
-# file containing qstr defs for the core Python bit
+# where autogenerated header files go
+HEADER_BUILD = $(BUILD)/includes/build
+
+# where autogenerated py header files go
+HEADER_PY_BUILD = $(HEADER_BUILD)/py
 
+# file containing qstr defs for the core Python bit
 PY_QSTR_DEFS = $(PY_SRC)/qstrdefs.h
 
 # py object files
@@ -100,26 +105,25 @@ PY_O = $(addprefix $(PY_BUILD)/, $(PY_O_BASENAME))
 FORCE:
 .PHONY: FORCE
 
-$(PY_BUILD)/py-version.h: FORCE
+$(HEADER_PY_BUILD)/py-version.h: FORCE
 	$(Q)$(PY_SRC)/py-version.sh > $@.tmp
 	$(Q)if [ -f "$@" ] && cmp -s $@ $@.tmp; then rm $@.tmp; else echo "Generating $@"; mv $@.tmp $@; fi
 
 # qstr data
 
-# Adding an order only dependency on $(PY_BUILD) causes $(PY_BUILD) to get
+# Adding an order only dependency on $(HEADER_PY_BUILD) causes $(HEADER_PY_BUILD) to get
 # created before we run the script to generate the .h
-$(PY_BUILD)/qstrdefs.generated.h: | $(PY_BUILD)/
-$(PY_BUILD)/qstrdefs.generated.h: $(PY_QSTR_DEFS) $(QSTR_DEFS) $(PY_SRC)/makeqstrdata.py mpconfigport.h $(PY_SRC)/mpconfig.h
+$(HEADER_PY_BUILD)/qstrdefs.generated.h: $(PY_QSTR_DEFS) $(QSTR_DEFS) $(PY_SRC)/makeqstrdata.py mpconfigport.h $(PY_SRC)/mpconfig.h | $(HEADER_PY_BUILD)
 	$(ECHO) "makeqstrdata $(PY_QSTR_DEFS) $(QSTR_DEFS)"
-	$(CPP) $(CFLAGS) $(PY_QSTR_DEFS) -o $(PY_BUILD)/qstrdefs.preprocessed.h
-	$(Q)$(PYTHON) $(PY_SRC)/makeqstrdata.py $(PY_BUILD)/qstrdefs.preprocessed.h $(QSTR_DEFS) > $@
+	$(CPP) $(CFLAGS) $(PY_QSTR_DEFS) -o $(HEADER_PY_BUILD)/qstrdefs.preprocessed.h
+	$(Q)$(PYTHON) $(PY_SRC)/makeqstrdata.py $(HEADER_PY_BUILD)/qstrdefs.preprocessed.h $(QSTR_DEFS) > $@
 
 # We don't know which source files actually need the generated.h (since
 # it is #included from str.h). The compiler generated dependencies will cause
 # the right .o's to get recompiled if the generated.h file changes. Adding
 # an order-only dependendency to all of the .o's will cause the generated .h
 # to get built before we try to compile any of them.
-$(PY_O): | $(PY_BUILD)/qstrdefs.generated.h $(PY_BUILD)/py-version.h
+$(PY_O): | $(HEADER_PY_BUILD)/qstrdefs.generated.h $(HEADER_PY_BUILD)/py-version.h
 
 # emitters
 
diff --git a/py/qstr.c b/py/qstr.c
index 990ff37727e39aaa7923c7d137674d8000aa7e6b..2b14065fa6fa0d60c017080cd4fd9450dd0214dc 100644
--- a/py/qstr.c
+++ b/py/qstr.c
@@ -60,7 +60,6 @@ const static qstr_pool_t const_pool = {
         (const byte*) "\0\0\0\0", // invalid/no qstr has empty data
         (const byte*) "\0\0\0\0", // empty qstr
 #define Q(id, str) str,
-// TODO having 'build/' here is a bit of a hack, should take config variable from Makefile
 #include "build/py/qstrdefs.generated.h"
 #undef Q
     },
diff --git a/py/qstr.h b/py/qstr.h
index 994c4180883bbd6c3ac3c3ba23a6a7bde19f2a57..6bcb1707fbdae89243c9db232995e8c820cf1203 100644
--- a/py/qstr.h
+++ b/py/qstr.h
@@ -8,7 +8,6 @@ enum {
     MP_QSTR_NULL = 0, // indicates invalid/no qstr
     MP_QSTR_ = 1, // the empty qstr
 #define Q(id, str) MP_QSTR_##id,
-// TODO having 'build/py.' here is a bit of a hack, should take config variable from Makefile
 #include "build/py/qstrdefs.generated.h"
 #undef Q
     MP_QSTR_number_of,
diff --git a/stm/Makefile b/stm/Makefile
index 25c79a27b22988bf882e425c434511d92903310b..384ecd6304ed31ff3ac7e7f83c2d1a04ba05f2e8 100644
--- a/stm/Makefile
+++ b/stm/Makefile
@@ -17,12 +17,19 @@ DFU=../tools/dfu.py
 
 CROSS_COMPILE = arm-none-eabi-
 
+INC =  -I.
+INC += -I$(PY_SRC)
+INC += -I$(BUILD)/includes
+INC += -I$(CMSIS_DIR)
+INC += -I$(STMPERIPH_DIR)
+INC += -I$(STMUSB_DIR)
+INC += -I$(STMUSBD_DIR)
+INC += -I$(STMUSBH_DIR)
+INC += -I$(FATFS_DIR)
+#INC += -I$(CC3K_DIR)
+
 CFLAGS_CORTEX_M4 = -mthumb -mtune=cortex-m4 -mabi=aapcs-linux -mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -mfloat-abi=hard -fsingle-precision-constant -Wdouble-promotion
-CFLAGS = -I. -I$(PY_SRC) -I$(CMSIS_DIR) -I$(STMPERIPH_DIR) -I$(STMUSB_DIR) -Wall -Werror -ansi -std=gnu99 $(CFLAGS_CORTEX_M4) $(COPT)
-CFLAGS += -I$(STMUSBD_DIR)
-CFLAGS += -I$(STMUSBH_DIR)
-CFLAGS += -I$(FATFS_DIR)
-#CFLAGS += -I$(CC3K_DIR)
+CFLAGS = $(INC) -Wall -Werror -ansi -std=gnu99 $(CFLAGS_CORTEX_M4) $(COPT)
 
 BOARD ?= PYBOARD4
 ifeq ($(wildcard boards/$(BOARD)/.),)
diff --git a/stmhal/Makefile b/stmhal/Makefile
index ac0367024aee82e833a2625184578afbf58fee45..27caaca0166106255683cdb9c05c04e1f1379f44 100644
--- a/stmhal/Makefile
+++ b/stmhal/Makefile
@@ -18,6 +18,7 @@ CROSS_COMPILE = arm-none-eabi-
 
 INC =  -I.
 INC += -I$(PY_SRC)
+INC += -I$(BUILD)/includes
 INC += -I$(CMSIS_DIR)/inc
 INC += -I$(CMSIS_DIR)/devinc
 INC += -I$(HAL_DIR)/inc
@@ -208,28 +209,28 @@ BOARD_PINS = boards/$(BOARD)/pins.csv
 AF_FILE = boards/stm32f4xx-af.csv
 PREFIX_FILE = boards/stm32f4xx-prefix.c
 GEN_PINS_SRC = $(BUILD)/pins_$(BOARD).c
-GEN_PINS_HDR = $(BUILD)/pins.h
+GEN_PINS_HDR = $(HEADER_BUILD)/pins.h
 
 INSERT_USB_IDS = ../tools/insert-usb-ids.py
 FILE2H = ../tools/file2h.py
 
 USB_IDS_FILE = usbd_desc_cdc_msc.c
 CDCINF_TEMPLATE = pybcdc.inf_template
-GEN_CDCINF_FILE = $(BUILD)/pybcdc.inf
-GEN_CDCINF_HEADER = $(BUILD)/pybcdc_inf.h
+GEN_CDCINF_FILE = $(HEADER_BUILD)/pybcdc.inf
+GEN_CDCINF_HEADER = $(HEADER_BUILD)/pybcdc_inf.h
 
 # Making OBJ use an order-only depenedency on the generated pins.h file
 # has the side effect of making the pins.h file before we actually compile
 # any of the objects. The normal dependency generation will deal with the
 # case when pins.h is modified. But when it doesn't exist, we don't know
 # which source files might need it.
-$(OBJ): | $(BUILD)/pins.h
+$(OBJ): | $(HEADER_BUILD)/pins.h
 
 $(BUILD)/main.o: $(GEN_CDCINF_HEADER)
 
 # Use a pattern rule here so that make will only call make-pins.py once to make
 # both pins_$(BOARD).c and pins.h
-$(BUILD)/%_$(BOARD).c $(BUILD)/%.h: boards/$(BOARD)/%.csv $(MAKE_PINS) $(AF_FILE) $(PREFIX_FILE)
+$(BUILD)/%_$(BOARD).c $(HEADER_BUILD)/%.h: boards/$(BOARD)/%.csv $(MAKE_PINS) $(AF_FILE) $(PREFIX_FILE)
 	$(ECHO) "Create $@"
 	$(Q)$(PYTHON) $(MAKE_PINS) --board $(BOARD_PINS) --af $(AF_FILE) --prefix $(PREFIX_FILE) --hdr $(GEN_PINS_HDR) > $(GEN_PINS_SRC)
 
diff --git a/teensy/Makefile b/teensy/Makefile
index 5630103e34c05afd0bed2b6f1a9006e223f28ad7..bd01f7e2b1179fbb498d3059c6dc12915f2d8ccd 100644
--- a/teensy/Makefile
+++ b/teensy/Makefile
@@ -17,7 +17,13 @@ CROSS_COMPILE = $(COMPILER_PATH)/arm-none-eabi-
 
 CFLAGS_TEENSY = -DF_CPU=96000000 -DUSB_SERIAL -D__MK20DX256__
 CFLAGS_CORTEX_M4 = -mthumb -mtune=cortex-m4 -mcpu=cortex-m4 -fsingle-precision-constant -Wdouble-promotion $(CFLAGS_TEENSY)
-CFLAGS = -I. -I$(PY_SRC) -I$(CORE_PATH) -Wall -ansi -std=gnu99 $(CFLAGS_CORTEX_M4)
+
+INC =  -I.
+INC += -I$(PY_SRC)
+INC += -I$(BUILD)/includes
+INC += -I$(CORE_PATH)
+
+CFLAGS = $(INC) -Wall -ansi -std=gnu99 $(CFLAGS_CORTEX_M4)
 LDFLAGS = -nostdlib -T mk20dx256.ld
 LIBS = -L $(COMPILER_PATH)/../lib/gcc/arm-none-eabi/4.7.2/thumb2 -lgcc
 
diff --git a/unix-cpy/Makefile b/unix-cpy/Makefile
index 985ef15854162c02f57586b8302d6230af4bc1f5..8db8c2069ab006841a64009dde233e72456352f5 100644
--- a/unix-cpy/Makefile
+++ b/unix-cpy/Makefile
@@ -6,8 +6,12 @@ PROG = cpy
 # include py core make definitions
 include ../py/py.mk
 
+INC =  -I.
+INC += -I$(PY_SRC)
+INC += -I$(BUILD)/includes
+
 # compiler settings
-CFLAGS = -I. -I$(PY_SRC) -Wall -Werror -ansi -std=gnu99 -DUNIX
+CFLAGS = $(INC) -Wall -Werror -ansi -std=gnu99 -DUNIX
 LDFLAGS = -lm
 
 # Debugging/Optimization
diff --git a/unix/Makefile b/unix/Makefile
index c9509b9f0de7c94fb0e7780a1c58e485ae1d4991..1a29363c91f2c5f85f48aa6d952192c8426fcb12 100644
--- a/unix/Makefile
+++ b/unix/Makefile
@@ -10,8 +10,12 @@ QSTR_DEFS = qstrdefsport.h
 # include py core make definitions
 include ../py/py.mk
 
+INC =  -I.
+INC += -I$(PY_SRC)
+INC += -I$(BUILD)/includes
+
 # compiler settings
-CFLAGS = -I. -I$(PY_SRC) -Wall -Werror -ansi -std=gnu99 -DUNIX $(CFLAGS_MOD) $(COPT)
+CFLAGS = $(INC) -Wall -Werror -ansi -std=gnu99 -DUNIX $(CFLAGS_MOD) $(COPT)
 
 UNAME_S := $(shell uname -s)
  ifeq ($(UNAME_S),Darwin)
diff --git a/windows/Makefile b/windows/Makefile
index 9bea574b6583ccba4a45afecfb1638decf24bf7c..ad4c82c128e7a0ed0a3d2c426053d89c40b3f5a9 100644
--- a/windows/Makefile
+++ b/windows/Makefile
@@ -9,8 +9,12 @@ QSTR_DEFS = ../unix/qstrdefsport.h
 # include py core make definitions
 include ../py/py.mk
 
+INC =  -I.
+INC += -I$(PY_SRC)
+INC += -I$(BUILD)/includes
+
 # compiler settings
-CFLAGS = -I. -I$(PY_SRC) -Wall -Werror -ansi -std=gnu99 -DUNIX
+CFLAGS = $(INC) -Wall -Werror -ansi -std=gnu99 -DUNIX
 LDFLAGS = -lm
 
 # Debugging/Optimization