diff --git a/basic/zflash.c b/basic/zflash.c
index a67fe44..aaa3674 100644
--- a/basic/zflash.c
+++ b/basic/zflash.c
@@ -106,7 +106,7 @@ bool zflash_flush(void) {
   HAL_FLASH_Unlock();  // 
   HAL_StatusTypeDef status;
   for (uint32_t i = 0; i < _rawsize; i++) {
-    status = HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, _flashadd + i * 4, _rawstartadd[i]);
+    status = HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, (uint32_t)_flashadd + i * 4, _rawstartadd[i]);
     if (status != HAL_OK) {
       ZLOGE("flash", "write error");
     }