diff --git a/storage/filesystem/fat/ChaN/ff.cpp b/storage/filesystem/fat/ChaN/ff.cpp
index 70e2d3f239f..53b23a71700 100644
--- a/storage/filesystem/fat/ChaN/ff.cpp
+++ b/storage/filesystem/fat/ChaN/ff.cpp
@@ -537,7 +537,7 @@ static WCHAR LfnBuf[FF_MAX_LFN + 1];		/* LFN working buffer */
 #elif FF_USE_LFN == 3 	/* LFN enabled with dynamic working buffer on the heap */
 #if FF_FS_EXFAT
 #define DEF_NAMBUF		WCHAR *lfn;	/* Pointer to LFN working buffer and directory entry block scratchpad buffer */
-#define INIT_NAMBUF(fs)	{ lfn = ff_memalloc((FF_MAX_LFN+1)*2 + MAXDIRB(FF_MAX_LFN)); if (!lfn) LEAVE_FF(fs, FR_NOT_ENOUGH_CORE); (fs)->lfnbuf = lfn; (fs)->dirbuf = (BYTE*)(lfn+FF_MAX_LFN+1); }
+#define INIT_NAMBUF(fs)	{ lfn = (WCHAR *)(ff_memalloc((FF_MAX_LFN+1)*2 + MAXDIRB(FF_MAX_LFN))); if (!lfn) LEAVE_FF(fs, FR_NOT_ENOUGH_CORE); (fs)->lfnbuf = lfn; (fs)->dirbuf = (BYTE*)(lfn+FF_MAX_LFN+1); }
 #define FREE_NAMBUF()	ff_memfree(lfn)
 #else
 #define DEF_NAMBUF		WCHAR *lfn;	/* Pointer to LFN working buffer */
@@ -555,6 +555,7 @@ static WCHAR LfnBuf[FF_MAX_LFN + 1];		/* LFN working buffer */
 
 
 
+
 /*--------------------------------*/
 /* Code conversion tables         */
 /*--------------------------------*/