diff --git a/README.md b/README.md
index c661200..bfca190 100644
--- a/README.md
+++ b/README.md
@@ -65,6 +65,8 @@ cmm question [-t OTAGS]... [-k ATAGS]... [-x XTAGS]... [-o OUTTAGS]... [-A AI_ID
 * `-O, --overwrite`: Overwrite existing messages when repeating them
 * `-s, --source-text FILE`: Add content of a file to the query
 * `-S, --source-code FILE`: Add source code file content to the chat history
+* `-l, --location {cache,db,all}`: Use given location when building the chat history (default: 'db')
+* `-g, --glob GLOB`: Filter message files using the given glob pattern
 
 #### Hist
 
@@ -83,6 +85,8 @@ cmm hist [--print | --convert FORMAT] [-t OTAGS]... [-k ATAGS]... [-x XTAGS]...
 * `-S, --source-code-only`: Only print embedded source code
 * `-A, --answer SUBSTRING`: Filter for answer substring
 * `-Q, --question SUBSTRING`: Filter for question substring
+* `-l, --location {cache,db,all}`: Use given location when building the chat history (default: 'db')
+* `-g, --glob GLOB`: Filter message files using the given glob pattern
 
 #### Tags
 
diff --git a/chatmastermind/chat.py b/chatmastermind/chat.py
index 1cc21ba..41a69bd 100644
--- a/chatmastermind/chat.py
+++ b/chatmastermind/chat.py
@@ -6,7 +6,8 @@ from pathlib import Path
 from pprint import PrettyPrinter
 from pydoc import pager
 from dataclasses import dataclass
-from typing import TypeVar, Type, Optional, Any, Callable, Literal, Union
+from enum import Enum
+from typing import TypeVar, Type, Optional, Any, Callable, Union
 from .configuration import default_config_file
 from .message import Message, MessageFilter, MessageError, MessageFormat, message_in, message_valid_formats
 from .tags import Tag
@@ -16,10 +17,17 @@ ChatDBInst = TypeVar('ChatDBInst', bound='ChatDB')
 
 db_next_file = '.next'
 ignored_files = [db_next_file, default_config_file]
-msg_location = Literal['mem', 'disk', 'cache', 'db', 'all']
 msg_suffix = Message.file_suffix_write
 
 
+class msg_location(Enum):
+    MEM = 'mem'
+    DISK = 'disk'
+    CACHE = 'cache'
+    DB = 'db'
+    ALL = 'all'
+
+
 class ChatError(Exception):
     pass
 
@@ -44,12 +52,12 @@ def read_dir(dir_path: Path,
     Parameters:
     * 'dir_path': source directory
     * 'glob': if specified, files will be filtered using 'path.glob()',
-      otherwise it uses 'path.iterdir()'.
+      otherwise it reads all files with the default message suffix
     * 'mfilter': use with 'Message.from_file()' to filter messages
       when reading them.
     """
     messages: list[Message] = []
-    file_iter = dir_path.glob(glob) if glob else dir_path.iterdir()
+    file_iter = dir_path.glob(glob) if glob else dir_path.glob(f'*{msg_suffix}')
     for file_path in sorted(file_iter):
         if (file_path.is_file()
            and file_path.name not in ignored_files  # noqa: W503
@@ -287,7 +295,7 @@ class ChatDB(Chat):
     # a MessageFilter that all messages must match (if given)
     mfilter: Optional[MessageFilter] = None
     # the glob pattern for all messages
-    glob: Optional[str] = None
+    glob: str = f'*{msg_suffix}'
     # message format (for writing)
     mformat: MessageFormat = Message.default_format
 
@@ -303,20 +311,28 @@ class ChatDB(Chat):
     def from_dir(cls: Type[ChatDBInst],
                  cache_path: Path,
                  db_path: Path,
-                 glob: Optional[str] = None,
-                 mfilter: Optional[MessageFilter] = None) -> ChatDBInst:
+                 glob: str = f'*{msg_suffix}',
+                 mfilter: Optional[MessageFilter] = None,
+                 loc: msg_location = msg_location.DB) -> ChatDBInst:
         """
         Create a 'ChatDB' instance from the given directory structure.
         Reads all messages from 'db_path' into the local message list.
         Parameters:
         * 'cache_path': path to the directory for temporary messages
         * 'db_path': path to the directory for persistent messages
-        * 'glob': if specified, files will be filtered using 'path.glob()',
-          otherwise it uses 'path.iterdir()'.
+        * 'glob': if specified, files will be filtered using 'path.glob()'
         * 'mfilter': use with 'Message.from_file()' to filter messages
           when reading them.
+        * 'loc': read messages from given location instead of 'db_path'
         """
-        messages = read_dir(db_path, glob, mfilter)
+        if loc == msg_location.MEM:
+            raise ChatError(f"Can't build ChatDB from message location '{loc}'")
+        messages: list[Message] = []
+        if loc in [msg_location.DB, msg_location.DISK, msg_location.ALL]:
+            messages.extend(read_dir(db_path, glob, mfilter))
+        if loc in [msg_location.CACHE, msg_location.DISK, msg_location.ALL]:
+            messages.extend(read_dir(cache_path, glob, mfilter))
+        messages.sort(key=lambda x: x.msg_id())
         return cls(messages, cache_path, db_path, mfilter, glob)
 
     @classmethod
@@ -386,7 +402,7 @@ class ChatDB(Chat):
     def msg_gather(self,
                    loc: msg_location,
                    require_file_path: bool = False,
-                   glob: Optional[str] = None,
+                   glob: str = f'*{msg_suffix}',
                    mfilter: Optional[MessageFilter] = None) -> list[Message]:
         """
         Gather and return messages from the given locations:
@@ -399,14 +415,14 @@ class ChatDB(Chat):
         If 'require_file_path' is True, return only files with a valid file_path.
         """
         loc_messages: list[Message] = []
-        if loc in ['mem', 'all']:
+        if loc in [msg_location.MEM, msg_location.ALL]:
             if require_file_path:
                 loc_messages += [m for m in self.messages if (m.file_path is not None and (mfilter is None or m.match(mfilter)))]
             else:
                 loc_messages += [m for m in self.messages if (mfilter is None or m.match(mfilter))]
-        if loc in ['cache', 'disk', 'all']:
+        if loc in [msg_location.CACHE, msg_location.DISK, msg_location.ALL]:
             loc_messages += read_dir(self.cache_path, glob=glob, mfilter=mfilter)
-        if loc in ['db', 'disk', 'all']:
+        if loc in [msg_location.DB, msg_location.DISK, msg_location.ALL]:
             loc_messages += read_dir(self.db_path, glob=glob, mfilter=mfilter)
         # remove_duplicates and sort the list
         unique_messages: list[Message] = []
@@ -422,7 +438,7 @@ class ChatDB(Chat):
 
     def msg_find(self,
                  msg_names: list[str],
-                 loc: msg_location = 'mem',
+                 loc: msg_location = msg_location.MEM,
                  ) -> list[Message]:
         """
         Search and return the messages with the given names. Names can either be filenames
@@ -440,7 +456,7 @@ class ChatDB(Chat):
         return [m for m in loc_messages
                 if any((m.file_path and self.msg_name_matches(m.file_path, mn)) for mn in msg_names)]
 
-    def msg_remove(self, msg_names: list[str], loc: msg_location = 'mem') -> None:
+    def msg_remove(self, msg_names: list[str], loc: msg_location = msg_location.MEM) -> None:
         """
         Remove the messages with the given names. Names can either be filenames
         (with or without suffix), full paths or Message.msg_id(). Also deletes the
@@ -452,7 +468,7 @@ class ChatDB(Chat):
         * 'db'   : messages in the DB directory
         * 'all'  : all messages ('mem' + 'disk')
         """
-        if loc != 'mem':
+        if loc != msg_location.MEM:
             # delete the message files first
             rm_messages = self.msg_find(msg_names, loc=loc)
             for m in rm_messages:
@@ -463,7 +479,7 @@ class ChatDB(Chat):
 
     def msg_latest(self,
                    mfilter: Optional[MessageFilter] = None,
-                   loc: msg_location = 'mem') -> Optional[Message]:
+                   loc: msg_location = msg_location.MEM) -> Optional[Message]:
         """
         Return the last added message (according to the file ID) that matches the given filter.
         Only consider messages with a valid file_path (except if loc is 'mem').
@@ -492,7 +508,7 @@ class ChatDB(Chat):
                     and message.file_path.parent.samefile(self.cache_path)  # noqa: W503
                     and message.file_path.exists())  # noqa: W503
         else:
-            return len(self.msg_find([message], loc='cache')) > 0
+            return len(self.msg_find([message], loc=msg_location.CACHE)) > 0
 
     def msg_in_db(self, message: Union[Message, str]) -> bool:
         """
@@ -504,9 +520,9 @@ class ChatDB(Chat):
                     and message.file_path.parent.samefile(self.db_path)  # noqa: W503
                     and message.file_path.exists())  # noqa: W503
         else:
-            return len(self.msg_find([message], loc='db')) > 0
+            return len(self.msg_find([message], loc=msg_location.DB)) > 0
 
-    def cache_read(self, glob: Optional[str] = None, mfilter: Optional[MessageFilter] = None) -> None:
+    def cache_read(self, glob: str = f'*{msg_suffix}', mfilter: Optional[MessageFilter] = None) -> None:
         """
         Read messages from the cache directory. New ones are added to the internal list,
         existing ones are replaced. A message is determined as 'existing' if a message
@@ -549,7 +565,7 @@ class ChatDB(Chat):
         self.messages += messages
         self.msg_sort()
 
-    def cache_clear(self, glob: Optional[str] = None) -> None:
+    def cache_clear(self, glob: str = f'*{msg_suffix}') -> None:
         """
         Delete all message files from the cache dir and remove them from the internal list.
         """
@@ -569,11 +585,11 @@ class ChatDB(Chat):
         self.cache_write([message])
         # remove the old one (if any)
         if old_path:
-            self.msg_remove([str(old_path)], loc='db')
+            self.msg_remove([str(old_path)], loc=msg_location.DB)
         # (re)add it to the internal list
         self.msg_add([message])
 
-    def db_read(self, glob: Optional[str] = None, mfilter: Optional[MessageFilter] = None) -> None:
+    def db_read(self, glob: str = f'*{msg_suffix}', mfilter: Optional[MessageFilter] = None) -> None:
         """
         Read messages from the DB directory. New ones are added to the internal list,
         existing ones are replaced. A message is determined as 'existing' if a message
@@ -628,6 +644,6 @@ class ChatDB(Chat):
         self.db_write([message])
         # remove the old one (if any)
         if old_path:
-            self.msg_remove([str(old_path)], loc='cache')
+            self.msg_remove([str(old_path)], loc=msg_location.CACHE)
         # (re)add it to the internal list
         self.msg_add([message])
diff --git a/chatmastermind/commands/hist.py b/chatmastermind/commands/hist.py
index 8e68320..b065afb 100644
--- a/chatmastermind/commands/hist.py
+++ b/chatmastermind/commands/hist.py
@@ -2,7 +2,7 @@ import sys
 import argparse
 from pathlib import Path
 from ..configuration import Config
-from ..chat import ChatDB
+from ..chat import ChatDB, msg_location
 from ..message import MessageFilter, Message
 
 
@@ -15,9 +15,10 @@ def convert_messages(args: argparse.Namespace, config: Config) -> None:
     ('.txt', '.yaml') to the latest default message file suffix ('.msg').
     """
     chat = ChatDB.from_dir(Path(config.cache),
-                           Path(config.db))
+                           Path(config.db),
+                           glob='*')
     # read all known message files
-    msgs = chat.msg_gather(loc='disk', glob='*.*')
+    msgs = chat.msg_gather(loc=msg_location.DISK, glob='*.*')
     # make a set of all message IDs
     msg_ids = set([m.msg_id() for m in msgs])
     # set requested format and write all messages
@@ -29,14 +30,14 @@ def convert_messages(args: argparse.Namespace, config: Config) -> None:
             m.file_path = m.file_path.with_suffix('')
     chat.msg_write(msgs)
     # read all messages with the current default suffix
-    msgs = chat.msg_gather(loc='disk', glob=f'*{msg_suffix}')
+    msgs = chat.msg_gather(loc=msg_location.DISK, glob=f'*{msg_suffix}')
     # make sure we converted all of the original messages
     for mid in msg_ids:
         if not any(mid == m.msg_id() for m in msgs):
             print(f"Message '{mid}' has not been found after conversion. Aborting.")
             sys.exit(1)
     # delete messages with old suffixes
-    msgs = chat.msg_gather(loc='disk', glob='*.*')
+    msgs = chat.msg_gather(loc=msg_location.DISK, glob='*.*')
     for m in msgs:
         if m.file_path and m.file_path.suffix != msg_suffix:
             m.rm_file()
@@ -55,7 +56,9 @@ def print_chat(args: argparse.Namespace, config: Config) -> None:
                             answer_contains=args.answer)
     chat = ChatDB.from_dir(Path(config.cache),
                            Path(config.db),
-                           mfilter=mfilter)
+                           mfilter=mfilter,
+                           loc=msg_location(args.location),
+                           glob=args.glob)
     chat.print(args.source_code_only,
                args.with_metadata,
                paged=not args.no_paging,
diff --git a/chatmastermind/commands/print.py b/chatmastermind/commands/print.py
index d2a66a1..e1d66ca 100644
--- a/chatmastermind/commands/print.py
+++ b/chatmastermind/commands/print.py
@@ -3,7 +3,7 @@ import argparse
 from pathlib import Path
 from ..configuration import Config
 from ..message import Message, MessageError
-from ..chat import ChatDB
+from ..chat import ChatDB, msg_location
 
 
 def print_message(message: Message, args: argparse.Namespace) -> None:
@@ -38,7 +38,7 @@ def print_cmd(args: argparse.Namespace, config: Config) -> None:
     # print latest message
     elif args.latest:
         chat = ChatDB.from_dir(Path(config.cache), Path(config.db))
-        latest = chat.msg_latest(loc='disk')
+        latest = chat.msg_latest(loc=msg_location.DISK)
         if not latest:
             print("No message found!")
             sys.exit(1)
diff --git a/chatmastermind/commands/question.py b/chatmastermind/commands/question.py
index 4e7d8e0..cd31d54 100644
--- a/chatmastermind/commands/question.py
+++ b/chatmastermind/commands/question.py
@@ -4,7 +4,7 @@ from pathlib import Path
 from itertools import zip_longest
 from copy import deepcopy
 from ..configuration import Config
-from ..chat import ChatDB
+from ..chat import ChatDB, msg_location
 from ..message import Message, MessageFilter, MessageError, Question, source_code
 from ..ai_factory import create_ai
 from ..ai import AI, AIResponse
@@ -186,7 +186,9 @@ def question_cmd(args: argparse.Namespace, config: Config) -> None:
                             tags_not=args.exclude_tags)
     chat = ChatDB.from_dir(cache_path=Path(config.cache),
                            db_path=Path(config.db),
-                           mfilter=mfilter)
+                           mfilter=mfilter,
+                           glob=args.glob,
+                           loc=msg_location(args.location))
     # if it's a new question, create and store it immediately
     if args.ask or args.create:
         message = create_message(chat, args)
@@ -202,14 +204,14 @@ def question_cmd(args: argparse.Namespace, config: Config) -> None:
         repeat_msgs: list[Message] = []
         # repeat latest message
         if len(args.repeat) == 0:
-            lmessage = chat.msg_latest(loc='cache')
+            lmessage = chat.msg_latest(loc=msg_location.CACHE)
             if lmessage is None:
                 print("No message found to repeat!")
                 sys.exit(1)
             repeat_msgs.append(lmessage)
         # repeat given message(s)
         else:
-            repeat_msgs = chat.msg_find(args.repeat, loc='disk')
+            repeat_msgs = chat.msg_find(args.repeat, loc=msg_location.DISK)
         repeat_messages(repeat_msgs, chat, args, config)
     # === PROCESS ===
     elif args.process is not None:
diff --git a/chatmastermind/main.py b/chatmastermind/main.py
index ff74d6c..3fba60f 100755
--- a/chatmastermind/main.py
+++ b/chatmastermind/main.py
@@ -14,6 +14,7 @@ from .commands.tags import tags_cmd
 from .commands.config import config_cmd
 from .commands.hist import hist_cmd
 from .commands.print import print_cmd
+from .chat import msg_location
 
 
 def tags_completer(prefix: str, parsed_args: Any, **kwargs: Any) -> list[str]:
@@ -65,6 +66,11 @@ def create_parser() -> argparse.ArgumentParser:
     question_group.add_argument('-c', '--create', nargs='+', help='Create a question', metavar='QUESTION')
     question_group.add_argument('-r', '--repeat', nargs='*', help='Repeat a question', metavar='MESSAGE')
     question_group.add_argument('-p', '--process', nargs='*', help='Process existing questions', metavar='MESSAGE')
+    question_cmd_parser.add_argument('-l', '--location',
+                                     choices=[x.value for x in msg_location if x not in [msg_location.MEM, msg_location.DISK]],
+                                     default='db',
+                                     help='Use given location when building the chat history (default: \'db\')')
+    question_cmd_parser.add_argument('-g', '--glob', help='Filter message files using the given glob pattern')
     question_cmd_parser.add_argument('-O', '--overwrite', help='Overwrite existing messages when repeating them',
                                      action='store_true')
     question_cmd_parser.add_argument('-s', '--source-text', nargs='+', help='Add content of a file to the query', metavar='FILE')
@@ -87,6 +93,11 @@ def create_parser() -> argparse.ArgumentParser:
     hist_cmd_parser.add_argument('-Q', '--question', help='Print only questions with given substring', metavar='SUBSTRING')
     hist_cmd_parser.add_argument('-d', '--tight', help='Print without message separators', action='store_true')
     hist_cmd_parser.add_argument('-P', '--no-paging', help='Print without paging', action='store_true')
+    hist_cmd_parser.add_argument('-l', '--location',
+                                 choices=[x.value for x in msg_location if x not in [msg_location.MEM, msg_location.DISK]],
+                                 default='db',
+                                 help='Use given location when building the chat history (default: \'db\')')
+    hist_cmd_parser.add_argument('-g', '--glob', help='Filter message files using the given glob pattern')
 
     # 'tags' command parser
     tags_cmd_parser = cmdparser.add_parser('tags',
diff --git a/tests/test_chat.py b/tests/test_chat.py
index 802616d..7f68113 100644
--- a/tests/test_chat.py
+++ b/tests/test_chat.py
@@ -7,7 +7,7 @@ from io import StringIO
 from unittest.mock import patch
 from chatmastermind.tags import TagLine
 from chatmastermind.message import Message, Question, Answer, Tag, MessageFilter
-from chatmastermind.chat import Chat, ChatDB, ChatError
+from chatmastermind.chat import Chat, ChatDB, ChatError, msg_location
 
 
 msg_suffix: str = Message.file_suffix_write
@@ -240,7 +240,8 @@ class TestChatDB(TestChatBase):
         msg_to_file_force_suffix(duplicate_message)
         with self.assertRaises(ChatError) as cm:
             ChatDB.from_dir(pathlib.Path(self.cache_path.name),
-                            pathlib.Path(self.db_path.name))
+                            pathlib.Path(self.db_path.name),
+                            glob='*')
         self.assertEqual(str(cm.exception), "Validation failed")
 
     def test_file_path_ID_exists(self) -> None:
@@ -595,92 +596,92 @@ class TestChatDB(TestChatBase):
         chat_db = ChatDB.from_dir(pathlib.Path(self.cache_path.name),
                                   pathlib.Path(self.db_path.name))
         # search for a DB file in memory
-        self.assertEqual(chat_db.msg_find([str(self.message1.file_path)], loc='mem'), [self.message1])
-        self.assertEqual(chat_db.msg_find([self.message1.msg_id()], loc='mem'), [self.message1])
-        self.assertEqual(chat_db.msg_find(['0001.msg'], loc='mem'), [self.message1])
-        self.assertEqual(chat_db.msg_find(['0001'], loc='mem'), [self.message1])
+        self.assertEqual(chat_db.msg_find([str(self.message1.file_path)], loc=msg_location.MEM), [self.message1])
+        self.assertEqual(chat_db.msg_find([self.message1.msg_id()], loc=msg_location.MEM), [self.message1])
+        self.assertEqual(chat_db.msg_find(['0001.msg'], loc=msg_location.MEM), [self.message1])
+        self.assertEqual(chat_db.msg_find(['0001'], loc=msg_location.MEM), [self.message1])
         # and on disk
-        self.assertEqual(chat_db.msg_find([str(self.message2.file_path)], loc='db'), [self.message2])
-        self.assertEqual(chat_db.msg_find([self.message2.msg_id()], loc='db'), [self.message2])
-        self.assertEqual(chat_db.msg_find(['0002.msg'], loc='db'), [self.message2])
-        self.assertEqual(chat_db.msg_find(['0002'], loc='db'), [self.message2])
+        self.assertEqual(chat_db.msg_find([str(self.message2.file_path)], loc=msg_location.DB), [self.message2])
+        self.assertEqual(chat_db.msg_find([self.message2.msg_id()], loc=msg_location.DB), [self.message2])
+        self.assertEqual(chat_db.msg_find(['0002.msg'], loc=msg_location.DB), [self.message2])
+        self.assertEqual(chat_db.msg_find(['0002'], loc=msg_location.DB), [self.message2])
         # now search the cache -> expect empty result
-        self.assertEqual(chat_db.msg_find([str(self.message3.file_path)], loc='cache'), [])
-        self.assertEqual(chat_db.msg_find([self.message3.msg_id()], loc='cache'), [])
-        self.assertEqual(chat_db.msg_find(['0003.msg'], loc='cache'), [])
-        self.assertEqual(chat_db.msg_find(['0003'], loc='cache'), [])
+        self.assertEqual(chat_db.msg_find([str(self.message3.file_path)], loc=msg_location.CACHE), [])
+        self.assertEqual(chat_db.msg_find([self.message3.msg_id()], loc=msg_location.CACHE), [])
+        self.assertEqual(chat_db.msg_find(['0003.msg'], loc=msg_location.CACHE), [])
+        self.assertEqual(chat_db.msg_find(['0003'], loc=msg_location.CACHE), [])
         # search for multiple messages
         # -> search one twice, expect result to be unique
         search_names = ['0001', '0002.msg', self.message3.msg_id(), str(self.message3.file_path)]
         expected_result = [self.message1, self.message2, self.message3]
-        result = chat_db.msg_find(search_names, loc='all')
+        result = chat_db.msg_find(search_names, loc=msg_location.ALL)
         self.assert_messages_equal(result, expected_result)
 
     def test_msg_latest(self) -> None:
         chat_db = ChatDB.from_dir(pathlib.Path(self.cache_path.name),
                                   pathlib.Path(self.db_path.name))
-        self.assertEqual(chat_db.msg_latest(loc='mem'), self.message4)
-        self.assertEqual(chat_db.msg_latest(loc='db'), self.message4)
-        self.assertEqual(chat_db.msg_latest(loc='disk'), self.message4)
-        self.assertEqual(chat_db.msg_latest(loc='all'), self.message4)
+        self.assertEqual(chat_db.msg_latest(loc=msg_location.MEM), self.message4)
+        self.assertEqual(chat_db.msg_latest(loc=msg_location.DB), self.message4)
+        self.assertEqual(chat_db.msg_latest(loc=msg_location.DISK), self.message4)
+        self.assertEqual(chat_db.msg_latest(loc=msg_location.ALL), self.message4)
         # the cache is currently empty:
-        self.assertIsNone(chat_db.msg_latest(loc='cache'))
+        self.assertIsNone(chat_db.msg_latest(loc=msg_location.CACHE))
         # add new messages to the cache dir
         new_message = Message(question=Question("New Question"),
                               answer=Answer("New Answer"))
         chat_db.cache_add([new_message])
-        self.assertEqual(chat_db.msg_latest(loc='cache'), new_message)
-        self.assertEqual(chat_db.msg_latest(loc='mem'), new_message)
-        self.assertEqual(chat_db.msg_latest(loc='disk'), new_message)
-        self.assertEqual(chat_db.msg_latest(loc='all'), new_message)
+        self.assertEqual(chat_db.msg_latest(loc=msg_location.CACHE), new_message)
+        self.assertEqual(chat_db.msg_latest(loc=msg_location.MEM), new_message)
+        self.assertEqual(chat_db.msg_latest(loc=msg_location.DISK), new_message)
+        self.assertEqual(chat_db.msg_latest(loc=msg_location.ALL), new_message)
         # the DB does not contain the new message
-        self.assertEqual(chat_db.msg_latest(loc='db'), self.message4)
+        self.assertEqual(chat_db.msg_latest(loc=msg_location.DB), self.message4)
 
     def test_msg_gather(self) -> None:
         chat_db = ChatDB.from_dir(pathlib.Path(self.cache_path.name),
                                   pathlib.Path(self.db_path.name))
         all_messages = [self.message1, self.message2, self.message3, self.message4]
-        self.assert_messages_equal(chat_db.msg_gather(loc='all'), all_messages)
-        self.assert_messages_equal(chat_db.msg_gather(loc='db'), all_messages)
-        self.assert_messages_equal(chat_db.msg_gather(loc='mem'), all_messages)
-        self.assert_messages_equal(chat_db.msg_gather(loc='disk'), all_messages)
-        self.assert_messages_equal(chat_db.msg_gather(loc='cache'), [])
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.ALL), all_messages)
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.DB), all_messages)
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.MEM), all_messages)
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.DISK), all_messages)
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.CACHE), [])
         # add a new message, but only to the internal list
         new_message = Message(Question("What?"))
         all_messages_mem = all_messages + [new_message]
         chat_db.msg_add([new_message])
-        self.assert_messages_equal(chat_db.msg_gather(loc='mem'), all_messages_mem)
-        self.assert_messages_equal(chat_db.msg_gather(loc='all'), all_messages_mem)
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.MEM), all_messages_mem)
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.ALL), all_messages_mem)
         # the nr. of messages on disk did not change -> expect old result
-        self.assert_messages_equal(chat_db.msg_gather(loc='db'), all_messages)
-        self.assert_messages_equal(chat_db.msg_gather(loc='disk'), all_messages)
-        self.assert_messages_equal(chat_db.msg_gather(loc='cache'), [])
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.DB), all_messages)
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.DISK), all_messages)
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.CACHE), [])
         # test with MessageFilter
-        self.assert_messages_equal(chat_db.msg_gather(loc='all', mfilter=MessageFilter(tags_or={Tag('tag1')})),
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.ALL, mfilter=MessageFilter(tags_or={Tag('tag1')})),
                                    [self.message1])
-        self.assert_messages_equal(chat_db.msg_gather(loc='disk', mfilter=MessageFilter(tags_or={Tag('tag2')})),
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.DISK, mfilter=MessageFilter(tags_or={Tag('tag2')})),
                                    [self.message2])
-        self.assert_messages_equal(chat_db.msg_gather(loc='cache', mfilter=MessageFilter(tags_or={Tag('tag3')})),
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.CACHE, mfilter=MessageFilter(tags_or={Tag('tag3')})),
                                    [])
-        self.assert_messages_equal(chat_db.msg_gather(loc='mem', mfilter=MessageFilter(question_contains="What")),
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.MEM, mfilter=MessageFilter(question_contains="What")),
                                    [new_message])
 
     def test_msg_move_and_gather(self) -> None:
         chat_db = ChatDB.from_dir(pathlib.Path(self.cache_path.name),
                                   pathlib.Path(self.db_path.name))
         all_messages = [self.message1, self.message2, self.message3, self.message4]
-        self.assert_messages_equal(chat_db.msg_gather(loc='db'), all_messages)
-        self.assert_messages_equal(chat_db.msg_gather(loc='cache'), [])
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.DB), all_messages)
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.CACHE), [])
         # move first message to the cache
         chat_db.cache_move(self.message1)
-        self.assert_messages_equal(chat_db.msg_gather(loc='cache'), [self.message1])
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.CACHE), [self.message1])
         self.assertEqual(self.message1.file_path.parent, pathlib.Path(self.cache_path.name))  # type: ignore [union-attr]
-        self.assert_messages_equal(chat_db.msg_gather(loc='db'), [self.message2, self.message3, self.message4])
-        self.assert_messages_equal(chat_db.msg_gather(loc='all'), all_messages)
-        self.assert_messages_equal(chat_db.msg_gather(loc='disk'), all_messages)
-        self.assert_messages_equal(chat_db.msg_gather(loc='mem'), all_messages)
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.DB), [self.message2, self.message3, self.message4])
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.ALL), all_messages)
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.DISK), all_messages)
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.MEM), all_messages)
         # now move first message back to the DB
         chat_db.db_move(self.message1)
-        self.assert_messages_equal(chat_db.msg_gather(loc='cache'), [])
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.CACHE), [])
         self.assertEqual(self.message1.file_path.parent, pathlib.Path(self.db_path.name))  # type: ignore [union-attr]
-        self.assert_messages_equal(chat_db.msg_gather(loc='db'), all_messages)
+        self.assert_messages_equal(chat_db.msg_gather(loc=msg_location.DB), all_messages)
diff --git a/tests/test_hist_cmd.py b/tests/test_hist_cmd.py
index cfd1c1f..2a8cbc1 100644
--- a/tests/test_hist_cmd.py
+++ b/tests/test_hist_cmd.py
@@ -4,7 +4,7 @@ import tempfile
 import yaml
 from pathlib import Path
 from chatmastermind.message import Message, Question
-from chatmastermind.chat import ChatDB, ChatError
+from chatmastermind.chat import ChatDB, ChatError, msg_location
 from chatmastermind.configuration import Config
 from chatmastermind.commands.hist import convert_messages
 
@@ -41,7 +41,7 @@ class TestConvertMessages(unittest.TestCase):
     def test_convert_messages(self) -> None:
         self.args.convert = 'yaml'
         convert_messages(self.args, self.config)
-        msgs = self.chat.msg_gather(loc='disk', glob='*.*')
+        msgs = self.chat.msg_gather(loc=msg_location.DISK, glob='*.*')
         # Check if the number of messages is the same as before
         self.assertEqual(len(msgs), len(self.messages))
         # Check if all messages have the requested suffix
diff --git a/tests/test_question_cmd.py b/tests/test_question_cmd.py
index be31b58..b809e4b 100644
--- a/tests/test_question_cmd.py
+++ b/tests/test_question_cmd.py
@@ -9,7 +9,7 @@ from chatmastermind.configuration import Config
 from chatmastermind.commands.question import create_message, question_cmd
 from chatmastermind.tags import Tag
 from chatmastermind.message import Message, Question, Answer
-from chatmastermind.chat import Chat, ChatDB
+from chatmastermind.chat import Chat, ChatDB, msg_location
 from chatmastermind.ai import AIError
 from .test_common import TestWithFakeAI
 
@@ -234,6 +234,8 @@ class TestQuestionCmd(TestWithFakeAI):
         # create a mock argparse.Namespace
         self.args = argparse.Namespace(
             ask=['What is the meaning of life?'],
+            glob=None,
+            location='db',
             num_answers=1,
             output_tags=['science'],
             AI='FakeAI',
@@ -279,7 +281,7 @@ class TestQuestionCmdAsk(TestQuestionCmd):
         # check for the expected message files
         chat = ChatDB.from_dir(Path(self.cache_dir.name),
                                Path(self.db_dir.name))
-        cached_msg = chat.msg_gather(loc='cache')
+        cached_msg = chat.msg_gather(loc=msg_location.CACHE)
         self.assertEqual(len(self.message_list(self.cache_dir)), 1)
         self.assert_msgs_equal_except_file_path(cached_msg, expected_responses)
 
@@ -337,7 +339,7 @@ class TestQuestionCmdAsk(TestQuestionCmd):
         # check for the expected message files
         chat = ChatDB.from_dir(Path(self.cache_dir.name),
                                Path(self.db_dir.name))
-        cached_msg = chat.msg_gather(loc='cache')
+        cached_msg = chat.msg_gather(loc=msg_location.CACHE)
         self.assertEqual(len(self.message_list(self.cache_dir)), 1)
         self.assert_msgs_equal_except_file_path(cached_msg, [expected_question])
 
@@ -375,7 +377,7 @@ class TestQuestionCmdRepeat(TestQuestionCmd):
         # we expect the original message + the one with the new response
         expected_responses = [message] + [expected_response]
         question_cmd(self.args, self.config)
-        cached_msg = chat.msg_gather(loc='cache')
+        cached_msg = chat.msg_gather(loc=msg_location.CACHE)
         print(self.message_list(self.cache_dir))
         self.assertEqual(len(self.message_list(self.cache_dir)), 2)
         self.assert_msgs_equal_except_file_path(cached_msg, expected_responses)
@@ -396,7 +398,7 @@ class TestQuestionCmdRepeat(TestQuestionCmd):
                           model=self.args.model,
                           file_path=Path(self.cache_dir.name) / f'0001{msg_suffix}')
         chat.msg_write([message])
-        cached_msg = chat.msg_gather(loc='cache')
+        cached_msg = chat.msg_gather(loc=msg_location.CACHE)
         assert cached_msg[0].file_path
         cached_msg_file_id = cached_msg[0].file_path.stem
 
@@ -412,7 +414,7 @@ class TestQuestionCmdRepeat(TestQuestionCmd):
                                     tags=message.tags,
                                     file_path=Path('<NOT COMPARED>'))
         question_cmd(self.args, self.config)
-        cached_msg = chat.msg_gather(loc='cache')
+        cached_msg = chat.msg_gather(loc=msg_location.CACHE)
         self.assertEqual(len(self.message_list(self.cache_dir)), 1)
         self.assert_msgs_equal_except_file_path(cached_msg, [expected_response])
         # also check that the file ID has not been changed
@@ -435,7 +437,7 @@ class TestQuestionCmdRepeat(TestQuestionCmd):
                           model=self.args.model,
                           file_path=Path(self.cache_dir.name) / f'0001{msg_suffix}')
         chat.msg_write([message])
-        cached_msg = chat.msg_gather(loc='cache')
+        cached_msg = chat.msg_gather(loc=msg_location.CACHE)
         assert cached_msg[0].file_path
         cached_msg_file_id = cached_msg[0].file_path.stem
 
@@ -452,7 +454,7 @@ class TestQuestionCmdRepeat(TestQuestionCmd):
                                     tags=message.tags,
                                     file_path=Path('<NOT COMPARED>'))
         question_cmd(self.args, self.config)
-        cached_msg = chat.msg_gather(loc='cache')
+        cached_msg = chat.msg_gather(loc=msg_location.CACHE)
         self.assertEqual(len(self.message_list(self.cache_dir)), 1)
         self.assert_msgs_equal_except_file_path(cached_msg, [expected_response])
         # also check that the file ID has not been changed
@@ -475,7 +477,7 @@ class TestQuestionCmdRepeat(TestQuestionCmd):
                           model=self.args.model,
                           file_path=Path(self.cache_dir.name) / f'0001{msg_suffix}')
         chat.msg_write([message])
-        cached_msg = chat.msg_gather(loc='cache')
+        cached_msg = chat.msg_gather(loc=msg_location.CACHE)
         assert cached_msg[0].file_path
 
         # repeat the last question with new arguments (without overwriting)
@@ -493,7 +495,7 @@ class TestQuestionCmdRepeat(TestQuestionCmd):
                                         tags={Tag('newtag')},
                                         file_path=Path('<NOT COMPARED>'))
         question_cmd(self.args, self.config)
-        cached_msg = chat.msg_gather(loc='cache')
+        cached_msg = chat.msg_gather(loc=msg_location.CACHE)
         self.assertEqual(len(self.message_list(self.cache_dir)), 2)
         self.assert_msgs_equal_except_file_path(cached_msg, [message] + [new_expected_response])
 
@@ -513,7 +515,7 @@ class TestQuestionCmdRepeat(TestQuestionCmd):
                           model=self.args.model,
                           file_path=Path(self.cache_dir.name) / f'0001{msg_suffix}')
         chat.msg_write([message])
-        cached_msg = chat.msg_gather(loc='cache')
+        cached_msg = chat.msg_gather(loc=msg_location.CACHE)
         assert cached_msg[0].file_path
 
         # repeat the last question with new arguments
@@ -530,7 +532,7 @@ class TestQuestionCmdRepeat(TestQuestionCmd):
                                         tags={Tag('newtag')},
                                         file_path=Path('<NOT COMPARED>'))
         question_cmd(self.args, self.config)
-        cached_msg = chat.msg_gather(loc='cache')
+        cached_msg = chat.msg_gather(loc=msg_location.CACHE)
         self.assertEqual(len(self.message_list(self.cache_dir)), 1)
         self.assert_msgs_equal_except_file_path(cached_msg, [new_expected_response])
 
@@ -586,8 +588,8 @@ class TestQuestionCmdRepeat(TestQuestionCmd):
         self.assertEqual(len(self.message_list(self.cache_dir)), 4)
         self.assertEqual(len(self.message_list(self.db_dir)), 1)
         expected_cache_messages = [expected_responses[0], message2, expected_responses[1], expected_responses[2]]
-        cached_msg = chat.msg_gather(loc='cache')
+        cached_msg = chat.msg_gather(loc=msg_location.CACHE)
         self.assert_msgs_equal_except_file_path(cached_msg, expected_cache_messages)
         # check that the DB message has not been modified at all
-        db_msg = chat.msg_gather(loc='db')
+        db_msg = chat.msg_gather(loc=msg_location.DB)
         self.assert_msgs_all_equal(db_msg, [message3])