diff --git a/kitty/actions.py b/kitty/actions.py
index b04f2648a..602ed9e3d 100644
--- a/kitty/actions.py
+++ b/kitty/actions.py
@@ -2,7 +2,7 @@
 # License: GPLv3 Copyright: 2021, Kovid Goyal <kovid at kovidgoyal.net>
 
 import inspect
-from typing import NamedTuple, cast
+from typing import Any, NamedTuple
 
 from .boss import Boss
 from .tabs import Tab
@@ -39,18 +39,19 @@ def get_all_actions() -> dict[ActionGroup, list[Action]]:
 
     ans: dict[ActionGroup, list[Action]] = {}
 
-    def is_action(x: object) -> bool:
+    def is_action(x: Any) -> bool:
         return isinstance(getattr(x, 'action_spec', None), ActionSpec)
 
-    def as_action(x: object) -> Action:
+    def as_action(x: Any) -> Action:
         spec: ActionSpec = getattr(x, 'action_spec')
         doc = inspect.cleandoc(spec.doc)
         lines = doc.splitlines()
         first = lines.pop(0)
         short_help = first
         long_help = '\n'.join(lines).strip()
-        assert spec.group in groups
-        return Action(getattr(x, '__name__'), cast(ActionGroup, spec.group), short_help, long_help)
+        if spec.group not in groups:
+            raise KeyError(f'Unknown action type: {spec.group}')
+        return Action(getattr(x, '__name__'), spec.group, short_help, long_help)
 
     seen = set()
     for cls in (Window, Tab, Boss):
diff --git a/kitty/open_actions.py b/kitty/open_actions.py
index 4cb78ed4b..715a40cd9 100644
--- a/kitty/open_actions.py
+++ b/kitty/open_actions.py
@@ -7,7 +7,7 @@ import posixpath
 import shlex
 from collections.abc import Iterable, Iterator
 from contextlib import suppress
-from typing import Any, NamedTuple, cast
+from typing import Any, NamedTuple
 from urllib.parse import ParseResult, unquote, urlparse
 
 from .conf.utils import KeyAction, to_cmdline_implementation
@@ -56,7 +56,7 @@ def parse(lines: Iterable[str]) -> Iterator[OpenAction]:
         elif key in ('mime', 'ext', 'protocol', 'file', 'path', 'url', 'fragment_matches'):
             if key != 'url':
                 rest = rest.lower()
-            match_criteria.append(MatchCriteria(cast(MatchType, key), rest))
+            match_criteria.append(MatchCriteria(key, rest))
         elif key == 'action_alias':
             try:
                 alias_name, alias_val = rest.split(maxsplit=1)