diff --git a/components/drivers/sdio/mmcsd_core.c b/components/drivers/sdio/mmcsd_core.c
index 777f15f2bb..d11bcce3a8 100644
--- a/components/drivers/sdio/mmcsd_core.c
+++ b/components/drivers/sdio/mmcsd_core.c
@@ -175,7 +175,7 @@ rt_int32_t mmcsd_get_cid(struct rt_mmcsd_host *host, rt_uint32_t *cid)
 		return 0;
 	}
 
-	buf = (rt_uint8_t *)rt_malloc(16);
+	buf = (rt_uint32_t *)rt_malloc(16);
 	if (!buf) 
 	{
 		rt_kprintf("allocate memory failed\n");
@@ -248,7 +248,7 @@ rt_int32_t mmcsd_get_csd(struct rt_mmcsd_card *card, rt_uint32_t *csd)
 		return 0;
 	}
 
-	buf = (rt_uint8_t*)rt_malloc(16);
+	buf = (rt_uint32_t*)rt_malloc(16);
 	if (!buf) 
 	{
 		rt_kprintf("allocate memory failed\n");