diff --git a/src/dpy_cache/dpy_cache.py b/src/dpy_cache/dpy_cache.py
index 57b33f2..ab6573c 100644
--- a/src/dpy_cache/dpy_cache.py
+++ b/src/dpy_cache/dpy_cache.py
@@ -61,9 +61,10 @@ import discord
 log = logging.getLogger(__name__)
 
 MAX_ATTACHMENTS_PER_MESSAGE = 10
-# cache_url's body cap: discord's largest upload tier (500 MB, nitro), so nothing discord would
-# accept is refused; it bounds memory, it is not the bot's real (per-guild) upload limit
-MAX_CACHE_URL_BYTES = 500 * 1024 * 1024
+# cache_url's body cap: the largest upload a BOT can make (boost tier 3 guild,
+# discord.py Guild.filesize_limit 104857600; bots can't have nitro), so nothing discord would
+# accept from a bot is refused; it bounds memory, not the channel's own (tier) limit
+MAX_CACHE_URL_BYTES = 100 * 1024 * 1024
 
 FileContent = Union[bytes, bytearray, str, "os.PathLike[str]", discord.File]