diff --git a/ports/stm32/main.c b/ports/stm32/main.c
index 5c75355422..d24200ba0f 100644
--- a/ports/stm32/main.c
+++ b/ports/stm32/main.c
@@ -130,6 +130,7 @@ STATIC mp_obj_t pyb_main(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_a
 }
 MP_DEFINE_CONST_FUN_OBJ_KW(pyb_main_obj, 1, pyb_main);
 
+#if MICROPY_HW_ENABLE_STORAGE
 static const char fresh_boot_py[] =
 "# boot.py -- run on boot-up\r\n"
 "# can run arbitrary Python, but best to keep it minimal\r\n"
@@ -264,6 +265,7 @@ MP_NOINLINE STATIC bool init_flash_fs(uint reset_mode) {
 
     return true;
 }
+#endif
 
 #if MICROPY_HW_HAS_SDCARD
 STATIC bool init_sdcard_fs(void) {
@@ -512,7 +514,9 @@ void stm32_main(uint32_t reset_mode) {
     #if MICROPY_HW_HAS_SDCARD
     sdcard_init();
     #endif
+    #if MICROPY_HW_ENABLE_STORAGE
     storage_init();
+    #endif
     #if MICROPY_PY_LWIP
     // lwIP doesn't allow to reinitialise itself by subsequent calls to this function
     // because the system timeout list (next_timeout) is only ever reset by BSS clearing.
@@ -599,7 +603,10 @@ soft_reset:
 
     // Initialise the local flash filesystem.
     // Create it if needed, mount in on /flash, and set it as current dir.
-    bool mounted_flash = init_flash_fs(reset_mode);
+    bool mounted_flash = false;
+    #if MICROPY_HW_ENABLE_STORAGE
+    mounted_flash = init_flash_fs(reset_mode);
+    #endif
 
     bool mounted_sdcard = false;
     #if MICROPY_HW_HAS_SDCARD
@@ -727,8 +734,10 @@ soft_reset_exit:
 
     // soft reset
 
+    #if MICROPY_HW_ENABLE_STORAGE
     printf("PYB: sync filesystems\n");
     storage_flush();
+    #endif
 
     printf("PYB: soft reboot\n");
     #if MICROPY_PY_NETWORK
diff --git a/ports/stm32/modmachine.c b/ports/stm32/modmachine.c
index 73442719b5..ff1eaec95f 100644
--- a/ports/stm32/modmachine.c
+++ b/ports/stm32/modmachine.c
@@ -231,7 +231,9 @@ STATIC NORETURN mp_obj_t machine_bootloader(void) {
     #if MICROPY_HW_ENABLE_USB
     pyb_usb_dev_deinit();
     #endif
+    #if MICROPY_HW_ENABLE_STORAGE
     storage_flush();
+    #endif
 
     HAL_RCC_DeInit();
     HAL_DeInit();
diff --git a/ports/stm32/mpconfigboard_common.h b/ports/stm32/mpconfigboard_common.h
index 7449a68956..919598de44 100644
--- a/ports/stm32/mpconfigboard_common.h
+++ b/ports/stm32/mpconfigboard_common.h
@@ -169,6 +169,13 @@
 #define MICROPY_HW_BDEV_WRITEBLOCK flash_bdev_writeblock
 #endif
 
+// Enable the storage sub-system if a block device is defined
+#if defined(MICROPY_HW_BDEV_IOCTL)
+#define MICROPY_HW_ENABLE_STORAGE (1)
+#else
+#define MICROPY_HW_ENABLE_STORAGE (0)
+#endif
+
 // Enable hardware I2C if there are any peripherals defined
 #if defined(MICROPY_HW_I2C1_SCL) || defined(MICROPY_HW_I2C2_SCL) \
     || defined(MICROPY_HW_I2C3_SCL) || defined(MICROPY_HW_I2C4_SCL)
diff --git a/ports/stm32/spibdev.c b/ports/stm32/spibdev.c
index 91ec4df5e9..b73058c6ab 100644
--- a/ports/stm32/spibdev.c
+++ b/ports/stm32/spibdev.c
@@ -30,6 +30,8 @@
 #include "led.h"
 #include "storage.h"
 
+#if MICROPY_HW_ENABLE_STORAGE
+
 int32_t spi_bdev_ioctl(spi_bdev_t *bdev, uint32_t op, uint32_t arg) {
     switch (op) {
         case BDEV_IOCTL_INIT:
@@ -79,3 +81,5 @@ int spi_bdev_writeblocks(spi_bdev_t *bdev, const uint8_t *src, uint32_t block_nu
 
     return ret;
 }
+
+#endif
diff --git a/ports/stm32/stm32_it.c b/ports/stm32/stm32_it.c
index b7124de894..b051382875 100644
--- a/ports/stm32/stm32_it.c
+++ b/ports/stm32/stm32_it.c
@@ -310,9 +310,11 @@ void SysTick_Handler(void) {
     // be generalised in the future then a dispatch table can be used as
     // follows: ((void(*)(void))(systick_dispatch[uwTick & 0xf]))();
 
+    #if MICROPY_HW_ENABLE_STORAGE
     if (STORAGE_IDLE_TICK(uwTick)) {
         NVIC->STIR = FLASH_IRQn;
     }
+    #endif
 
     if (DMA_IDLE_ENABLED() && DMA_IDLE_TICK(uwTick)) {
         dma_idle_handler(uwTick);
@@ -459,8 +461,10 @@ void FLASH_IRQHandler(void) {
         HAL_FLASH_IRQHandler();
     }
     */
+    #if MICROPY_HW_ENABLE_STORAGE
     // This call the storage IRQ handler, to check if the flash cache needs flushing
     storage_irq_handler();
+    #endif
     IRQ_EXIT(FLASH_IRQn);
 }
 
diff --git a/ports/stm32/storage.c b/ports/stm32/storage.c
index 2ac54a4010..761db0b525 100644
--- a/ports/stm32/storage.c
+++ b/ports/stm32/storage.c
@@ -34,6 +34,8 @@
 #include "storage.h"
 #include "irq.h"
 
+#if MICROPY_HW_ENABLE_STORAGE
+
 #define FLASH_PART1_START_BLOCK (0x100)
 
 #if defined(MICROPY_HW_BDEV2_IOCTL)
@@ -284,3 +286,5 @@ void pyb_flash_init_vfs(fs_user_mount_t *vfs) {
     vfs->u.ioctl[0] = (mp_obj_t)&pyb_flash_ioctl_obj;
     vfs->u.ioctl[1] = (mp_obj_t)&pyb_flash_obj;
 }
+
+#endif