diff --git a/docs/misc/bvid_desc.md b/docs/misc/bvid_desc.md
index bf14b86..97a6bd0 100644
--- a/docs/misc/bvid_desc.md
+++ b/docs/misc/bvid_desc.md
@@ -167,8 +167,8 @@ def av2bv(aid: int) -> str:
     bvid = [""] * 9
     tmp = (MAX_AID | aid) ^ XOR_CODE
     for i in range(CODE_LEN):
-        bvid[ENCODE_MAP[i]] = ALPHABET[int(tmp % BASE)]
-        tmp /= BASE
+        bvid[ENCODE_MAP[i]] = ALPHABET[tmp % BASE]
+        tmp //= BASE
     return PREFIX + "".join(bvid)
 
 def bv2av(bvid: str) -> int: