diff --git a/fs/Vfat.cpp b/fs/Vfat.cpp
index 38681c9..1803c4b 100644
--- a/fs/Vfat.cpp
+++ b/fs/Vfat.cpp
@@ -139,7 +139,7 @@
     flags |= (ro ? MS_RDONLY : 0);
     flags |= (remount ? MS_REMOUNT : 0);
 
-    sprintf(mountData,
+    snprintf(mountData, sizeof(mountData),
             "utf8,uid=%d,gid=%d,fmask=%o,dmask=%o,shortname=mixed",
             ownerUid, ownerGid, permMask, permMask);