diff --git a/fs/exfat/nls.c b/fs/exfat/nls.c
index 8243d94ceaf4..a52f3494eb20 100644
--- a/fs/exfat/nls.c
+++ b/fs/exfat/nls.c
@@ -616,7 +616,7 @@ static int exfat_nls_to_ucs2(struct super_block *sb,
 		unilen++;
 	}
 
-	if (p_cstring[i] != '\0')
+	if (p_cstring[min(i, len - 1)] != '\0')
 		lossy |= NLS_NAME_OVERLEN;
 
 	*uniname = '\0';