diff --git a/discord/ext/commands/bot.py b/discord/ext/commands/bot.py
index 79e15f0c..24502f84 100644
--- a/discord/ext/commands/bot.py
+++ b/discord/ext/commands/bot.py
@@ -148,6 +148,19 @@ def _unwrap_slash_groups(data: ApplicationCommandInteractionData) -> Tuple[str,
 
     return command_name, command_options
 
+def _quote_string_safe(string: str) -> str:
+    # we need to quote this string otherwise we may spill into
+    # other parameters and cause all kinds of trouble, as many
+    # quotes are supported and some may be in the option, we
+    # loop through all supported quotes and if neither open or
+    # close are in the string, we add them
+    for open, close in supported_quotes.items():
+        if open not in string and close not in string:
+            return f"{open}{string}{close}"
+
+    # all supported quotes are in the message and we cannot add any
+    # safely, very unlikely but still got to be covered
+    raise errors.UnexpectedQuoteError(string)
 
 class _DefaultRepr:
     def __repr__(self):
@@ -1177,12 +1190,15 @@ class BotBase(GroupMixin):
             prefix = prefix[0]
 
         # Add arguments to fake message content, in the right order
+        ignore_params: List[inspect.Parameter] = []
         message.content = f'{prefix}{command_name} '
         for name, param in command.clean_params.items():
             option = next((o for o in command_options if o['name'] == name), None) # type: ignore
             if option is None:
                 if param.default is param.empty and not command._is_typing_optional(param.annotation):
                     raise errors.MissingRequiredArgument(param)
+                else:
+                    ignore_params.append(param)
             elif (
                 option["type"] == 3
                 and param.kind != param.KEYWORD_ONLY
@@ -1190,28 +1206,13 @@ class BotBase(GroupMixin):
             ):
                 # String with space in without "consume rest"
                 option = cast(_ApplicationCommandInteractionDataOptionString, option)
-
-                # we need to quote this string otherwise we may spill into
-                # other parameters and cause all kinds of trouble, as many
-                # quotes are supported and some may be in the option, we
-                # loop through all supported quotes and if neither open or
-                # close are in the string, we add them
-                quoted = False
-                string = option['value']
-                for open, close in supported_quotes.items():
-                    if open not in string and close not in string:
-                        message.content += f"{open}{string}{close} "
-                        quoted = True
-                        break
-
-                # all supported quotes are in the message and we cannot add any
-                # safely, very unlikely but still got to be covered
-                if not quoted:
-                    raise errors.UnexpectedQuoteError(string)
+                quoted_string = _quote_string_safe(option['value'])
+                message.content += f'{quoted_string} '
             else:
                 message.content += f'{option.get("value", "")} '
 
         ctx = await self.get_context(message)
+        ctx._ignored_params = ignore_params
         ctx.interaction = interaction
         await self.invoke(ctx)
 
diff --git a/discord/ext/commands/context.py b/discord/ext/commands/context.py
index 8cc2afb6..73d8d8fb 100644
--- a/discord/ext/commands/context.py
+++ b/discord/ext/commands/context.py
@@ -154,6 +154,7 @@ class Context(discord.abc.Messageable, Generic[BotT]):
         self.subcommand_passed: Optional[str] = subcommand_passed
         self.command_failed: bool = command_failed
         self.current_parameter: Optional[inspect.Parameter] = current_parameter
+        self._ignored_params: List[inspect.Parameter] = []
         self._state: ConnectionState = self.message._state
 
     async def invoke(self, command: Command[CogT, P, T], /, *args: P.args, **kwargs: P.kwargs) -> T:
diff --git a/discord/ext/commands/core.py b/discord/ext/commands/core.py
index b23f8d16..30d11883 100644
--- a/discord/ext/commands/core.py
+++ b/discord/ext/commands/core.py
@@ -577,6 +577,10 @@ class Command(_BaseCommand, Generic[CogT, P, T]):
             ctx.bot.dispatch('command_error', ctx, error)
 
     async def transform(self, ctx: Context, param: inspect.Parameter) -> Any:
+        if param in ctx._ignored_params:
+            # in a slash command, we need a way to mark a param as default so ctx._ignored_params is used
+            return param.default if param.default is not param.empty else None
+
         required = param.default is param.empty
         converter = get_converter(param)
         consume_rest_is_special = param.kind == param.KEYWORD_ONLY and not self.rest_is_raw