diff --git a/components/dfs/filesystems/elmfat/dfs_elm.c b/components/dfs/filesystems/elmfat/dfs_elm.c
index 750a1cdc14c2fe71f743e8f431daed2e5b9439c8..4a69b6a64f4be801f1b55d3ebaad3f311b73e922 100644
--- a/components/dfs/filesystems/elmfat/dfs_elm.c
+++ b/components/dfs/filesystems/elmfat/dfs_elm.c
@@ -182,7 +182,7 @@ int dfs_elm_mkfs(rt_device_t dev_id)
 {
 #define FSM_STATUS_INIT            0
 #define FSM_STATUS_USE_TEMP_DRIVER 1
-    FATFS *fat;
+    FATFS *fat = RT_NULL;
     int flag;
     FRESULT result;
     int index;