diff --git a/embed/boardloader/main.c b/embed/boardloader/main.c
index e2d8fd39..a8a5f908 100644
--- a/embed/boardloader/main.c
+++ b/embed/boardloader/main.c
@@ -124,7 +124,7 @@ static secbool copy_sdcard(void)
 
     uint32_t buf[SDCARD_BLOCK_SIZE / sizeof(uint32_t)];
     for (int i = 0; i < (IMAGE_HEADER_SIZE + codelen) / SDCARD_BLOCK_SIZE; i++) {
-        sdcard_read_blocks((uint8_t *)buf, i, 1);
+        sdcard_read_blocks(buf, i, 1);
         for (int j = 0; j < SDCARD_BLOCK_SIZE / sizeof(uint32_t); j++) {
             if (sectrue != flash_write_word(BOOTLOADER_START + i * SDCARD_BLOCK_SIZE + j * sizeof(uint32_t), buf[j])) {
                 display_printf("copy failed\n");
diff --git a/embed/trezorhal/sdcard.c b/embed/trezorhal/sdcard.c
index dd5f0edb..c4606a63 100644
--- a/embed/trezorhal/sdcard.c
+++ b/embed/trezorhal/sdcard.c
@@ -150,7 +150,7 @@ static HAL_StatusTypeDef sdcard_wait_finished(SD_HandleTypeDef *sd, uint32_t tim
     return HAL_OK;
 }
 
-secbool sdcard_read_blocks(void *dest, uint32_t block_num, uint32_t num_blocks) {
+secbool sdcard_read_blocks(uint32_t *dest, uint32_t block_num, uint32_t num_blocks) {
     // check that SD card is initialised
     if (sd_handle.Instance == NULL) {
         return secfalse;
@@ -163,7 +163,7 @@ secbool sdcard_read_blocks(void *dest, uint32_t block_num, uint32_t num_blocks)
 
     HAL_StatusTypeDef err = HAL_OK;
 
-    err = HAL_SD_ReadBlocks(&sd_handle, dest, block_num, num_blocks, 60000);
+    err = HAL_SD_ReadBlocks(&sd_handle, (uint8_t *)dest, block_num, num_blocks, 60000);
     if (err == HAL_OK) {
         err = sdcard_wait_finished(&sd_handle, 60000);
     }
@@ -171,7 +171,7 @@ secbool sdcard_read_blocks(void *dest, uint32_t block_num, uint32_t num_blocks)
     return sectrue * (err == HAL_OK);
 }
 
-secbool sdcard_write_blocks(const void *src, uint32_t block_num, uint32_t num_blocks) {
+secbool sdcard_write_blocks(const uint32_t *src, uint32_t block_num, uint32_t num_blocks) {
     // check that SD card is initialised
     if (sd_handle.Instance == NULL) {
         return secfalse;
@@ -184,7 +184,7 @@ secbool sdcard_write_blocks(const void *src, uint32_t block_num, uint32_t num_bl
 
     HAL_StatusTypeDef err = HAL_OK;
 
-    err = HAL_SD_WriteBlocks(&sd_handle, (uint8_t*)src, block_num, num_blocks, 60000);
+    err = HAL_SD_WriteBlocks(&sd_handle, (uint8_t *)src, block_num, num_blocks, 60000);
     if (err == HAL_OK) {
         err = sdcard_wait_finished(&sd_handle, 60000);
     }
diff --git a/embed/trezorhal/sdcard.h b/embed/trezorhal/sdcard.h
index feaa823c..011180f7 100644
--- a/embed/trezorhal/sdcard.h
+++ b/embed/trezorhal/sdcard.h
@@ -37,7 +37,7 @@ secbool sdcard_is_present(void);
 secbool sdcard_power_on(void);
 secbool sdcard_power_off(void);
 uint64_t sdcard_get_capacity_in_bytes(void);
-secbool sdcard_read_blocks(void *dest, uint32_t block_num, uint32_t num_blocks);
-secbool sdcard_write_blocks(const void *src, uint32_t block_num, uint32_t num_blocks);
+secbool sdcard_read_blocks(uint32_t *dest, uint32_t block_num, uint32_t num_blocks);
+secbool sdcard_write_blocks(const uint32_t *src, uint32_t block_num, uint32_t num_blocks);
 
 #endif