diff --git a/ports/atmel-samd/boards/aloriumtech_evo_m51/mpconfigboard.mk b/ports/atmel-samd/boards/aloriumtech_evo_m51/mpconfigboard.mk
index 3b5b05020d..a46a36a811 100644
--- a/ports/atmel-samd/boards/aloriumtech_evo_m51/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/aloriumtech_evo_m51/mpconfigboard.mk
@@ -13,3 +13,4 @@ EXTERNAL_FLASH_DEVICES = GD25Q16C
 LONGINT_IMPL = MPZ
 
 CIRCUITPY_PS2IO = 1
+CIRCUITPY_SYNTHIO = 0
diff --git a/ports/atmel-samd/boards/circuitbrains_deluxe_m4/mpconfigboard.mk b/ports/atmel-samd/boards/circuitbrains_deluxe_m4/mpconfigboard.mk
index a96326c3b1..1346c73756 100755
--- a/ports/atmel-samd/boards/circuitbrains_deluxe_m4/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/circuitbrains_deluxe_m4/mpconfigboard.mk
@@ -11,3 +11,4 @@ EXTERNAL_FLASH_DEVICES = "W25Q64JVxQ, S25FL064L"
 LONGINT_IMPL = MPZ
 
 CIRCUITPY_PS2IO = 1
+CIRCUITPY_SYNTHIO = 0
diff --git a/ports/atmel-samd/boards/datalore_ip_m4/mpconfigboard.mk b/ports/atmel-samd/boards/datalore_ip_m4/mpconfigboard.mk
index b07f86c160..5aba5a76f6 100644
--- a/ports/atmel-samd/boards/datalore_ip_m4/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/datalore_ip_m4/mpconfigboard.mk
@@ -9,3 +9,4 @@ CHIP_FAMILY = samd51
 QSPI_FLASH_FILESYSTEM = 1
 EXTERNAL_FLASH_DEVICES = "GD25Q16C, W25Q16JVxQ, W25Q16JVxM"
 LONGINT_IMPL = MPZ
+CIRCUITPY_SYNTHIO = 0
diff --git a/ports/atmel-samd/boards/hallowing_m4_express/mpconfigboard.mk b/ports/atmel-samd/boards/hallowing_m4_express/mpconfigboard.mk
index 51fccc56e5..3924186d4b 100644
--- a/ports/atmel-samd/boards/hallowing_m4_express/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/hallowing_m4_express/mpconfigboard.mk
@@ -9,3 +9,4 @@ CHIP_FAMILY = samd51
 QSPI_FLASH_FILESYSTEM = 1
 EXTERNAL_FLASH_DEVICES = "GD25Q64C,W25Q64JVxQ"
 LONGINT_IMPL = MPZ
+CIRCUITPY_SYNTHIO = 0
diff --git a/ports/atmel-samd/boards/monster_m4sk/mpconfigboard.mk b/ports/atmel-samd/boards/monster_m4sk/mpconfigboard.mk
index 56dab1d788..87efe005f3 100644
--- a/ports/atmel-samd/boards/monster_m4sk/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/monster_m4sk/mpconfigboard.mk
@@ -9,3 +9,4 @@ CHIP_FAMILY = samd51
 QSPI_FLASH_FILESYSTEM = 1
 EXTERNAL_FLASH_DEVICES = "GD25Q64C,W25Q64JVxQ"
 LONGINT_IMPL = MPZ
+CIRCUITPY_SYNTHIO = 0
diff --git a/ports/atmel-samd/boards/openbook_m4/mpconfigboard.mk b/ports/atmel-samd/boards/openbook_m4/mpconfigboard.mk
index c46ed6a9fd..e624b8b94e 100644
--- a/ports/atmel-samd/boards/openbook_m4/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/openbook_m4/mpconfigboard.mk
@@ -11,3 +11,4 @@ EXTERNAL_FLASH_DEVICES = GD25Q16C
 LONGINT_IMPL = MPZ
 
 CIRCUITPY_KEYPAD = 1
+CIRCUITPY_SYNTHIO = 0
diff --git a/ports/atmel-samd/boards/seeeduino_wio_terminal/mpconfigboard.mk b/ports/atmel-samd/boards/seeeduino_wio_terminal/mpconfigboard.mk
index fefc78addc..3441e601b8 100644
--- a/ports/atmel-samd/boards/seeeduino_wio_terminal/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/seeeduino_wio_terminal/mpconfigboard.mk
@@ -9,3 +9,4 @@ CHIP_FAMILY = samd51
 QSPI_FLASH_FILESYSTEM = 1
 EXTERNAL_FLASH_DEVICES = "W25Q32JVxQ"
 LONGINT_IMPL = MPZ
+CIRCUITPY_SYNTHIO = 0
diff --git a/ports/atmel-samd/boards/silicognition-m4-shim/mpconfigboard.mk b/ports/atmel-samd/boards/silicognition-m4-shim/mpconfigboard.mk
index 58411aa03e..d7a12fc21c 100644
--- a/ports/atmel-samd/boards/silicognition-m4-shim/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/silicognition-m4-shim/mpconfigboard.mk
@@ -9,3 +9,4 @@ CHIP_FAMILY = samd51
 QSPI_FLASH_FILESYSTEM = 1
 EXTERNAL_FLASH_DEVICES = GD25Q16C
 LONGINT_IMPL = MPZ
+CIRCUITPY_SYNTHIO = 0
diff --git a/ports/atmel-samd/boards/uartlogger2/mpconfigboard.mk b/ports/atmel-samd/boards/uartlogger2/mpconfigboard.mk
index 87619b5783..edacd59a1b 100644
--- a/ports/atmel-samd/boards/uartlogger2/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/uartlogger2/mpconfigboard.mk
@@ -9,3 +9,4 @@ CHIP_FAMILY = samd51
 QSPI_FLASH_FILESYSTEM = 1
 EXTERNAL_FLASH_DEVICES = "W25Q32JVxQ"
 LONGINT_IMPL = MPZ
+CIRCUITPY_SYNTHIO = 0
diff --git a/ports/stm/boards/thunderpack_v12/mpconfigboard.mk b/ports/stm/boards/thunderpack_v12/mpconfigboard.mk
index 526415ca30..51d0429327 100644
--- a/ports/stm/boards/thunderpack_v12/mpconfigboard.mk
+++ b/ports/stm/boards/thunderpack_v12/mpconfigboard.mk
@@ -11,9 +11,10 @@ LONGINT_IMPL = NONE
 SPI_FLASH_FILESYSTEM = 1
 EXTERNAL_FLASH_DEVICES = GD25Q16C
 
-CIRCUITPY_NVM = 1
 CIRCUITPY_BITMAPTOOLS = 0
 CIRCUITPY_BLEIO_HCI = 0
+CIRCUITPY_NVM = 1
+CIRCUITPY_SYNTHIO = 0
 CIRCUITPY_ZLIB = 0
 
 MCU_SERIES = F4