diff --git a/pyobs/application.py b/pyobs/application.py
index 3a6eb09e..408ecff4 100644
--- a/pyobs/application.py
+++ b/pyobs/application.py
@@ -6,7 +6,7 @@
 import threading
 from io import StringIO
 from logging.handlers import TimedRotatingFileHandler
-from typing import Optional, Any, Dict
+from typing import Optional, Any, Dict, List
 import yaml
 
 from pyobs.object import get_object, get_class_from_string
@@ -35,7 +35,7 @@ def __init__(self, config: str, log_file: Optional[str] = None, log_level: str =
 
         # formatter for logging, and list of logging handlers
         formatter = logging.Formatter("%(asctime)s [%(levelname)s] %(filename)s:%(lineno)d %(message)s")
-        handlers = []
+        handlers: List[logging.Handler] = []
 
         # create stdout logging handler
         stream_handler = logging.StreamHandler()
@@ -110,7 +110,7 @@ def run(self) -> None:
         log.info("Closing loop...")
         self._loop.close()
 
-    def _signal_handler(self, sig) -> None:
+    def _signal_handler(self, sig: int) -> None:
         """React to signals and quit module."""
 
         # stop loop
diff --git a/pyobs/cli/pyobs.py b/pyobs/cli/pyobs.py
index fe99ce24..dd1513ea 100755
--- a/pyobs/cli/pyobs.py
+++ b/pyobs/cli/pyobs.py
@@ -1,11 +1,14 @@
 import argparse
 import os
-from typing import Type, Any
+from typing import Type, Any, Optional, TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from pyobs.application import Application
 
 from pyobs import version
 
 
-def init_cli():
+def init_cli() -> argparse.ArgumentParser:
     # init argument parsing
     # for all command line parameters we set the default to an environment variable,
     # so they can also be specified that way
@@ -30,7 +33,7 @@ def init_cli():
     return parser
 
 
-def parse_cli(parser: argparse.ArgumentParser):
+def parse_cli(parser: argparse.ArgumentParser) -> dict[str, Any]:
     from pyobs.utils.time import Time
 
     # parse args
@@ -50,7 +53,7 @@ def parse_cli(parser: argparse.ArgumentParser):
     return vars(args)
 
 
-def start_daemon(app_class, pid_file=None, **kwargs: Any) -> None:
+def start_daemon(app_class: Type["Application"], pid_file: str, **kwargs: Any) -> None:
     """Start process as a daemon.
 
     Args:
@@ -70,7 +73,7 @@ def start_daemon(app_class, pid_file=None, **kwargs: Any) -> None:
         run(app_class, **kwargs)
 
 
-def run(app_class: Type, **kwargs: Any) -> None:
+def run(app_class: Type["Application"], **kwargs: Any) -> None:
     """Run a pyobs application with the given options.
 
     Args:
diff --git a/pyobs/cli/pyobsw.py b/pyobs/cli/pyobsw.py
index 815d726b..a9c9748c 100644
--- a/pyobs/cli/pyobsw.py
+++ b/pyobs/cli/pyobsw.py
@@ -1,7 +1,7 @@
 from .pyobs import init_cli, parse_cli, run
 
 
-def main():
+def main() -> None:
     from pyobs.application import GuiApplication
 
     # init argument parsing and parse it