diff --git a/bot.py b/bot.py
index 6f84e52..68cc4ed 100755
--- a/bot.py
+++ b/bot.py
@@ -74,9 +74,11 @@ class BotClient(discord.Client):
     async def on_command(self, message: discord.Message):
         match message.content.split(" "):
             case ["%calc", *args]:
-                reply = await self._calculate(args)
-                if reply:
-                    await message.reply(content=reply.strip())
+                try:
+                    calc = await self._calculate(args)
+                    await message.reply(content=calc.strip())
+                except Exception as e:
+                    await message.reply(content="```\n" + str(e) + "\n```")
             case _:
                 _log.info(f"Unrecognised command {command}")
 
@@ -86,7 +88,7 @@ class BotClient(discord.Client):
         )
         if proc.returncode != 0:
             _log.error(f"running calculator: {proc.stderr}")
-        return proc.stdout
+        return proc.stdout.decode()
 
     def is_replay(self, message: discord.Message) -> bool:
         if re.match("https://replay.pokemonshowdown.com/dl-.*", message.content):