diff --git a/platforms/nuttx/src/px4/stm/stm32_common/include/px4_arch/px4io_serial.h b/platforms/nuttx/src/px4/stm/stm32_common/include/px4_arch/px4io_serial.h
index f8888f4024..27c2dacefc 100644
--- a/platforms/nuttx/src/px4/stm/stm32_common/include/px4_arch/px4io_serial.h
+++ b/platforms/nuttx/src/px4/stm/stm32_common/include/px4_arch/px4io_serial.h
@@ -41,6 +41,7 @@
 
 #include <board_config.h>
 #include <px4_config.h>
+#include <px4_micro_hal.h>
 
 #include <perf/perf_counter.h>
 
@@ -164,6 +165,6 @@ private:
 	/**
 	 * IO Buffer storage
 	 */
-	static uint8_t _io_buffer_storage[] __attribute__((aligned(PX4IO_SERIAL_BUF_ALIGN)));
+	static uint8_t _io_buffer_storage[] __attribute__((aligned(PX4_ARCH_DCACHE_LINESIZE)));
 };
 
diff --git a/platforms/nuttx/src/px4/stm/stm32f4/include/px4_arch/micro_hal.h b/platforms/nuttx/src/px4/stm/stm32f4/include/px4_arch/micro_hal.h
index 2c06c7641c..c997c4f473 100644
--- a/platforms/nuttx/src/px4/stm/stm32f4/include/px4_arch/micro_hal.h
+++ b/platforms/nuttx/src/px4/stm/stm32f4/include/px4_arch/micro_hal.h
@@ -46,6 +46,7 @@ __BEGIN_DECLS
 # define PX4_BBSRAM_GETDESC_IOCTL STM32_BBSRAM_GETDESC_IOCTL
 #endif
 #define PX4_NUMBER_I2C_BUSES STM32_NI2C
+#define PX4_ARCH_DCACHE_LINESIZE 32
 
 __END_DECLS
 
diff --git a/platforms/nuttx/src/px4/stm/stm32f4/include/px4_arch/px4io_serial.h b/platforms/nuttx/src/px4/stm/stm32f4/include/px4_arch/px4io_serial.h
index 77564d2ad0..5898838ee4 100644
--- a/platforms/nuttx/src/px4/stm/stm32f4/include/px4_arch/px4io_serial.h
+++ b/platforms/nuttx/src/px4/stm/stm32f4/include/px4_arch/px4io_serial.h
@@ -33,6 +33,5 @@
 
 #pragma once
 
-#define PX4IO_SERIAL_BUF_ALIGN 4
 #include "../../../stm32_common/include/px4_arch/px4io_serial.h"
 
diff --git a/platforms/nuttx/src/px4/stm/stm32f7/include/px4_arch/micro_hal.h b/platforms/nuttx/src/px4/stm/stm32f7/include/px4_arch/micro_hal.h
index af9a595895..c7d0ca02e6 100644
--- a/platforms/nuttx/src/px4/stm/stm32f7/include/px4_arch/micro_hal.h
+++ b/platforms/nuttx/src/px4/stm/stm32f7/include/px4_arch/micro_hal.h
@@ -46,6 +46,7 @@ __BEGIN_DECLS
 #define PX4_BBSRAM_GETDESC_IOCTL STM32F7_BBSRAM_GETDESC_IOCTL
 #define PX4_FLASH_BASE  0x08000000
 #define PX4_NUMBER_I2C_BUSES STM32F7_NI2C
+#define PX4_ARCH_DCACHE_LINESIZE ARMV7M_DCACHE_LINESIZE
 
 void stm32_flash_lock(void);
 void stm32_flash_unlock(void);
diff --git a/platforms/nuttx/src/px4/stm/stm32f7/include/px4_arch/px4io_serial.h b/platforms/nuttx/src/px4/stm/stm32f7/include/px4_arch/px4io_serial.h
index 0e78048670..5898838ee4 100644
--- a/platforms/nuttx/src/px4/stm/stm32f7/include/px4_arch/px4io_serial.h
+++ b/platforms/nuttx/src/px4/stm/stm32f7/include/px4_arch/px4io_serial.h
@@ -33,6 +33,5 @@
 
 #pragma once
 
-#define PX4IO_SERIAL_BUF_ALIGN ARMV7M_DCACHE_LINESIZE
 #include "../../../stm32_common/include/px4_arch/px4io_serial.h"