diff --git a/bare-arm/Makefile b/bare-arm/Makefile
index ace508ebd8996bedfe9ee1f1def329e790b622db..f9c9fb9a3141854803a662d1b74f58b1e358cc72 100644
--- a/bare-arm/Makefile
+++ b/bare-arm/Makefile
@@ -10,7 +10,7 @@ CROSS_COMPILE = arm-none-eabi-
 
 INC =  -I.
 INC += -I$(PY_SRC)
-INC += -I$(BUILD)/includes
+INC += -I$(BUILD)
 
 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 = $(INC) -Wall -Werror -ansi -std=gnu99 $(CFLAGS_CORTEX_M4) $(COPT)
diff --git a/py/mkrules.mk b/py/mkrules.mk
index 63a98a8ec6af520dcb6c7f29ff8d9d677fabd0f5..9592d6c590454d751e9af496b57ea5dc48d6563d 100644
--- a/py/mkrules.mk
+++ b/py/mkrules.mk
@@ -51,24 +51,21 @@ $(BUILD)/%.pp: %.c
 
 # The following rule uses | to create an order only prereuisite. Order only
 # prerequisites only get built if they don't exist. They don't cause timestamp
-# checkng to be performed.
+# checking to be performed.
 #
 # $(sort $(var)) removes duplicates
 #
 # The net effect of this, is it causes the objects to depend on the
-# object directories (but only for existance), and the object directories
+# object directories (but only for existence), and the object directories
 # will be created if they don't exist.
 OBJ_DIRS = $(sort $(dir $(OBJ)))
-$(OBJ): $(HEADER_PY_BUILD)/qstrdefs.generated.h | $(OBJ_DIRS)
+$(OBJ): $(HEADER_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 01a5fd1c2bb0d850e551ea301051271ed5e9aed8..dd6ddd0b35cca7c3906a7536f8a7af5fb21b2358 100644
--- a/py/py.mk
+++ b/py/py.mk
@@ -2,10 +2,7 @@
 PY_BUILD = $(BUILD)/py
 
 # where autogenerated header files go
-HEADER_BUILD = $(BUILD)/includes/build
-
-# where autogenerated py header files go
-HEADER_PY_BUILD = $(HEADER_BUILD)/py
+HEADER_BUILD = $(BUILD)/genhdr
 
 # file containing qstr defs for the core Python bit
 PY_QSTR_DEFS = $(PY_SRC)/qstrdefs.h
@@ -105,25 +102,26 @@ PY_O = $(addprefix $(PY_BUILD)/, $(PY_O_BASENAME))
 FORCE:
 .PHONY: FORCE
 
-$(HEADER_PY_BUILD)/py-version.h: FORCE
+$(HEADER_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 $(HEADER_PY_BUILD) causes $(HEADER_PY_BUILD) to get
+# Adding an order only dependency on $(HEADER_BUILD) causes $(HEADER_BUILD) to get
 # created before we run the script to generate the .h
-$(HEADER_PY_BUILD)/qstrdefs.generated.h: $(PY_QSTR_DEFS) $(QSTR_DEFS) $(PY_SRC)/makeqstrdata.py mpconfigport.h $(PY_SRC)/mpconfig.h | $(HEADER_PY_BUILD)
+$(HEADER_BUILD)/qstrdefs.generated.h: $(PY_QSTR_DEFS) $(QSTR_DEFS) $(PY_SRC)/makeqstrdata.py mpconfigport.h $(PY_SRC)/mpconfig.h | $(HEADER_BUILD)
+	$(ECHO) "CPP $<"
+	$(Q)$(CPP) $(CFLAGS) $(PY_QSTR_DEFS) -o $(HEADER_BUILD)/qstrdefs.preprocessed.h
 	$(ECHO) "makeqstrdata $(PY_QSTR_DEFS) $(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) > $@
+	$(Q)$(PYTHON) $(PY_SRC)/makeqstrdata.py $(HEADER_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): | $(HEADER_PY_BUILD)/qstrdefs.generated.h $(HEADER_PY_BUILD)/py-version.h
+$(PY_O): | $(HEADER_BUILD)/qstrdefs.generated.h $(HEADER_BUILD)/py-version.h
 
 # emitters
 
diff --git a/py/qstr.c b/py/qstr.c
index 2b14065fa6fa0d60c017080cd4fd9450dd0214dc..f9f63da3914094aeaa8a1fe26f2224ea2448fe72 100644
--- a/py/qstr.c
+++ b/py/qstr.c
@@ -60,7 +60,7 @@ 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,
-#include "build/py/qstrdefs.generated.h"
+#include "genhdr/qstrdefs.generated.h"
 #undef Q
     },
 };
diff --git a/py/qstr.h b/py/qstr.h
index 6bcb1707fbdae89243c9db232995e8c820cf1203..7cb6ae2e98d2f78e19511229106e9d2ec410c6f7 100644
--- a/py/qstr.h
+++ b/py/qstr.h
@@ -8,7 +8,7 @@ enum {
     MP_QSTR_NULL = 0, // indicates invalid/no qstr
     MP_QSTR_ = 1, // the empty qstr
 #define Q(id, str) MP_QSTR_##id,
-#include "build/py/qstrdefs.generated.h"
+#include "genhdr/qstrdefs.generated.h"
 #undef Q
     MP_QSTR_number_of,
 };
diff --git a/stm/Makefile b/stm/Makefile
index 384ecd6304ed31ff3ac7e7f83c2d1a04ba05f2e8..ab4d0ff3ff695cb6e14955aec776983749499be9 100644
--- a/stm/Makefile
+++ b/stm/Makefile
@@ -19,7 +19,7 @@ CROSS_COMPILE = arm-none-eabi-
 
 INC =  -I.
 INC += -I$(PY_SRC)
-INC += -I$(BUILD)/includes
+INC += -I$(BUILD)
 INC += -I$(CMSIS_DIR)
 INC += -I$(STMPERIPH_DIR)
 INC += -I$(STMUSB_DIR)
diff --git a/stmhal/Makefile b/stmhal/Makefile
index 27caaca0166106255683cdb9c05c04e1f1379f44..5501c4b8d9aca33d2e3cfba52fbf49c407b7c59a 100644
--- a/stmhal/Makefile
+++ b/stmhal/Makefile
@@ -18,7 +18,7 @@ CROSS_COMPILE = arm-none-eabi-
 
 INC =  -I.
 INC += -I$(PY_SRC)
-INC += -I$(BUILD)/includes
+INC += -I$(BUILD)
 INC += -I$(CMSIS_DIR)/inc
 INC += -I$(CMSIS_DIR)/devinc
 INC += -I$(HAL_DIR)/inc
diff --git a/stmhal/adc.c b/stmhal/adc.c
index dafa3f7bce4bd421cd5dc533b5df18457ee9b2e3..b0a7a0749add198a5da5f1afb1eb6bc25d62d19a 100644
--- a/stmhal/adc.c
+++ b/stmhal/adc.c
@@ -10,7 +10,7 @@
 #include "runtime.h"
 #include "adc.h"
 #include "pin.h"
-#include "build/pins.h"
+#include "genhdr/pins.h"
 #include "timer.h"
 
 // Usage Model:
diff --git a/stmhal/led.c b/stmhal/led.c
index 5c2d2c60a4fe0be018a64783c91aac7264e0dab5..52a787eedee5f2e8a17d47eb990a11b6f41fa3a0 100644
--- a/stmhal/led.c
+++ b/stmhal/led.c
@@ -10,7 +10,7 @@
 #include "timer.h"
 #include "led.h"
 #include "pin.h"
-#include "build/pins.h"
+#include "genhdr/pins.h"
 
 typedef struct _pyb_led_obj_t {
     mp_obj_base_t base;
diff --git a/stmhal/main.c b/stmhal/main.c
index 2d7e76172f0dc1c153378637098eae8f6650eebb..4fa5b2a436ff2ed30098174a8b86ac1d37145c71 100644
--- a/stmhal/main.c
+++ b/stmhal/main.c
@@ -134,7 +134,7 @@ static const char fresh_main_py[] =
 ;
 
 static const char fresh_pybcdc_inf[] =
-#include "build/pybcdc_inf.h"
+#include "genhdr/pybcdc_inf.h"
 ;
 
 static const char fresh_readme_txt[] =
diff --git a/stmhal/pyexec.c b/stmhal/pyexec.c
index 9821e6a92934d19383082d4bd5dcc5249aee6cb0..3f9482ec589749f682fe1de0f73f38c4160ffb1e 100644
--- a/stmhal/pyexec.c
+++ b/stmhal/pyexec.c
@@ -22,7 +22,7 @@
 #include "readline.h"
 #include "pyexec.h"
 #include "usb.h"
-#include "build/py/py-version.h"
+#include "genhdr/py-version.h"
 
 pyexec_mode_kind_t pyexec_mode_kind = PYEXEC_MODE_FRIENDLY_REPL;
 STATIC bool repl_display_debugging_info = 0;
diff --git a/stmhal/sdcard.c b/stmhal/sdcard.c
index 994eb26c2a306906745299a3107ef3b733064a2c..4c8e3d990bd27dbcb0a6d95bea1dbe9fb3b3895e 100644
--- a/stmhal/sdcard.c
+++ b/stmhal/sdcard.c
@@ -9,7 +9,7 @@
 #include "runtime.h"
 #include "sdcard.h"
 #include "pin.h"
-#include "build/pins.h"
+#include "genhdr/pins.h"
 
 #if MICROPY_HW_HAS_SDCARD
 
diff --git a/stmhal/usrsw.c b/stmhal/usrsw.c
index 5133392ccd91ea3eb209010228f4fe5cced8ce29..0ab407cd96ff5256b4c77e780b7196821123d022 100644
--- a/stmhal/usrsw.c
+++ b/stmhal/usrsw.c
@@ -11,7 +11,7 @@
 #include "exti.h"
 #include "gpio.h"
 #include "pin.h"
-#include "build/pins.h"
+#include "genhdr/pins.h"
 
 // Usage Model:
 //
diff --git a/teensy/Makefile b/teensy/Makefile
index bd01f7e2b1179fbb498d3059c6dc12915f2d8ccd..00f3514724c9269670b5a33128b85eeb4050fda5 100644
--- a/teensy/Makefile
+++ b/teensy/Makefile
@@ -20,7 +20,7 @@ CFLAGS_CORTEX_M4 = -mthumb -mtune=cortex-m4 -mcpu=cortex-m4 -fsingle-precision-c
 
 INC =  -I.
 INC += -I$(PY_SRC)
-INC += -I$(BUILD)/includes
+INC += -I$(BUILD)
 INC += -I$(CORE_PATH)
 
 CFLAGS = $(INC) -Wall -ansi -std=gnu99 $(CFLAGS_CORTEX_M4)
diff --git a/unix-cpy/Makefile b/unix-cpy/Makefile
index 8db8c2069ab006841a64009dde233e72456352f5..0376932d6a012e0d5323790a10ff54ce5ed76d2f 100644
--- a/unix-cpy/Makefile
+++ b/unix-cpy/Makefile
@@ -8,7 +8,7 @@ include ../py/py.mk
 
 INC =  -I.
 INC += -I$(PY_SRC)
-INC += -I$(BUILD)/includes
+INC += -I$(BUILD)
 
 # compiler settings
 CFLAGS = $(INC) -Wall -Werror -ansi -std=gnu99 -DUNIX
diff --git a/unix/Makefile b/unix/Makefile
index 1a29363c91f2c5f85f48aa6d952192c8426fcb12..ec02ad5004cde74bf04cd7544bbc47ea24c3bf16 100644
--- a/unix/Makefile
+++ b/unix/Makefile
@@ -12,7 +12,7 @@ include ../py/py.mk
 
 INC =  -I.
 INC += -I$(PY_SRC)
-INC += -I$(BUILD)/includes
+INC += -I$(BUILD)
 
 # compiler settings
 CFLAGS = $(INC) -Wall -Werror -ansi -std=gnu99 -DUNIX $(CFLAGS_MOD) $(COPT)
diff --git a/unix/main.c b/unix/main.c
index e582244b394e8a5173b8d8f1f03a7d72977e5148..b9b8fe0b9fe9445155d08e906ffbd52df7dc9c15 100644
--- a/unix/main.c
+++ b/unix/main.c
@@ -22,7 +22,7 @@
 #include "runtime.h"
 #include "repl.h"
 #include "gc.h"
-#include "build/py/py-version.h"
+#include "genhdr/py-version.h"
 
 #if MICROPY_USE_READLINE
 #include <readline/readline.h>
diff --git a/windows/Makefile b/windows/Makefile
index ad4c82c128e7a0ed0a3d2c426053d89c40b3f5a9..651de7c7f12c3898a7cf9f054ebe884d8a66c1b9 100644
--- a/windows/Makefile
+++ b/windows/Makefile
@@ -11,7 +11,7 @@ include ../py/py.mk
 
 INC =  -I.
 INC += -I$(PY_SRC)
-INC += -I$(BUILD)/includes
+INC += -I$(BUILD)
 
 # compiler settings
 CFLAGS = $(INC) -Wall -Werror -ansi -std=gnu99 -DUNIX