Cleanup previous PR

Actually respect the fallback order when finding matching shortcuts
2026-06-08 22:28:24 +02:00 · 2026-03-26 09:30:14 +05:30
parent 3e5b3eb55d
commit 88ee80b327
8 changed files with 130 additions and 90 deletions
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -168,6 +168,8 @@ Detailed list of changes
 0.47.0 [future]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

+- For builtin key mappings automatically fallback to matching ASCII key when the pressed key has no matches and is a non-English character (:pull:`9671`)
+
 - :doc:`Remote control <remote-control>`: Expose :code:`session_name` in the output of ``kitten @ ls`` for each window (:iss:`9732`)

 - Fix thickness of diagonal lines in box drawing characters not the same as horizontal/vertical lines (:iss:`9719`)
@@ -184,6 +186,7 @@ Detailed list of changes

 - The :opt:`show_hyperlink_targets` option now allows specifying a keyboard modifier so that target URLs are only shown on hover when the modifier is pressed (:pull:`9741`)

+
 0.46.2 [2026-03-21]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

--- a/kitty/conf/generate.py
+++ b/kitty/conf/generate.py
@@ -173,6 +173,8 @@ def generate_class(defn: Definition, loc: str) -> tuple[str, str]:
            fmod = f'{loc}.options.utils'
        imports.add((fmod, ftype))
        return ftype
+    if loc == 'kitty':
+        imports.add(('kitty.options.utils', 'KeyFallbackType'))

    for aname, action in defn.actions.items():
        option_names.add(aname)
@@ -620,7 +622,7 @@ def gen_go_code(defn: Definition) -> str:
        a('KeyboardShortcuts: []*config.KeyAction{')
        for sc in keyboard_shortcuts:
            options, leftover = parse_options_for_map(sc.parseable_text)
-            allow_fallback = options.allow_fallback
+            allow_fallback = ','.join(x.value for x in options.allow_fallback)
            key_spec, action = leftover.split(None, 1)
            aname, _, aargs = action.partition(' ')
            aname = serialize_as_go_string(aname)
--- a/kitty/conf/types.py
+++ b/kitty/conf/types.py
@@ -445,7 +445,7 @@ class ShortcutMapping(Mapping):
        from kitty.options.utils import parse_options_for_map
        _, remainder = parse_options_for_map(raw_definition)
        parts = remainder.split(maxsplit=1)
-        self.key = parts[0] if parts else ''
+        self.key = parts[0]
        self.action_def = parts[1] if len(parts) > 1 else ''

    @property
--- a/kitty/keys.py
+++ b/kitty/keys.py
@@ -23,14 +23,14 @@ from .fast_data_types import (
    set_ignore_os_keyboard_processing,
 )
 from .options.types import Options
-from .options.utils import KeyboardMode, KeyDefinition, KeyMap, KeyMapOptions
+from .options.utils import KeyboardMode, KeyDefinition, KeyFallbackType, KeyMap, KeyMapOptions
 from .typing_compat import ScreenType

 if TYPE_CHECKING:
    from .window import Window

 mod_mask = GLFW_MOD_ALT | GLFW_MOD_CONTROL | GLFW_MOD_SHIFT | GLFW_MOD_SUPER | GLFW_MOD_META | GLFW_MOD_HYPER
-_global_shortcut_options = KeyMapOptions(allow_fallback='shifted,ascii')
+_global_shortcut_options = KeyMapOptions(allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate))


 def keyboard_mode_name(screen: ScreenType) -> str:
@@ -43,24 +43,37 @@ def keyboard_mode_name(screen: ScreenType) -> str:
 def get_shortcut(keymap: KeyMap, ev: KeyEvent) -> list[KeyDefinition] | None:
    mods = ev.mods & mod_mask
    ans = keymap.get(SingleKey(mods, False, ev.key))
-    if ans is None and ev.shifted_key and mods & GLFW_MOD_SHIFT:
-        candidate = keymap.get(SingleKey(mods & (~GLFW_MOD_SHIFT), False, ev.shifted_key))
-        if candidate:
-            filtered = [d for d in candidate if 'shifted' in d.options.allow_fallback]
-            if filtered:
-                ans = filtered
-    if ans is None and ev.alternate_key and 127 < ev.key < 0xE000:
-        candidate = keymap.get(SingleKey(mods, False, ev.alternate_key))
-        if candidate:
-            filtered = [d for d in candidate if 'ascii' in d.options.allow_fallback]
-            if filtered:
-                ans = filtered
+    if ans is None:
+        priority_map: dict[int, int] = {}
+        items: list[KeyDefinition] = []
+
+        def add(q: list[KeyDefinition] | None, ft: KeyFallbackType) -> None:
+            if q:
+                for d in q:
+                    prio = -1
+                    for i, x in enumerate(d.options.allow_fallback):
+                        if x is ft:
+                            prio = i
+                            break
+                    key = id(d)
+                    if -1 < prio < priority_map.get(key, 100000):
+                        if key not in priority_map:
+                            items.append(d)
+                        priority_map[key] = prio
+        if ev.shifted_key and mods & GLFW_MOD_SHIFT:
+            add(keymap.get(SingleKey(mods & (~GLFW_MOD_SHIFT), False, ev.shifted_key)), KeyFallbackType.shifted)
+        if ev.alternate_key and 127 < ev.key < 0xE000:
+            add(keymap.get(SingleKey(mods, False, ev.alternate_key)), KeyFallbackType.alternate)
+        if items:
+            ans = sorted(items, key=lambda x: priority_map[id(x)])
+
    if ans is None:
        ans = keymap.get(SingleKey(mods, True, ev.native_key))
    return ans


 def shortcut_matches(s: SingleKey, ev: KeyEvent) -> bool:
+    ' used only for testing '
    mods = ev.mods & mod_mask
    smods = s.mods & mod_mask
    if s.is_native:
--- a/kitty/options/types.py
+++ b/kitty/options/types.py
@@ -11,8 +11,8 @@ import kitty.fast_data_types
 from kitty.fonts import FontSpec
 import kitty.fonts
 from kitty.options.utils import (
-    AliasMap, KeyDefinition, KeyMapOptions, KeyboardModeMap, MouseHideWait, MouseMap, MouseMapping,
-    NotifyOnCmdFinish, TabBarMarginHeight
+    AliasMap, KeyDefinition, KeyFallbackType, KeyMapOptions, KeyboardModeMap, MouseHideWait, MouseMap,
+    MouseMapping, NotifyOnCmdFinish, TabBarMarginHeight
 )
 import kitty.options.utils
 from kitty.types import FloatEdges
@@ -848,23 +848,23 @@ defaults.watcher = {}

 defaults.map = [
    # copy_to_clipboard
-    KeyDefinition(trigger=SingleKey(mods=256, key=99), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='copy_to_clipboard'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=99), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='copy_to_clipboard'),
    # paste_from_clipboard
-    KeyDefinition(trigger=SingleKey(mods=256, key=118), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='paste_from_clipboard'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=118), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='paste_from_clipboard'),
    # paste_from_selection
-    KeyDefinition(trigger=SingleKey(mods=256, key=115), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='paste_from_selection'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=115), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='paste_from_selection'),
    # paste_from_selection
    KeyDefinition(trigger=SingleKey(mods=1, key=57348), definition='paste_from_selection'),
    # pass_selection_to_program
-    KeyDefinition(trigger=SingleKey(mods=256, key=111), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='pass_selection_to_program'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=111), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='pass_selection_to_program'),
    # scroll_line_up
    KeyDefinition(trigger=SingleKey(mods=256, key=57352), definition='scroll_line_up'),
    # scroll_line_up
-    KeyDefinition(trigger=SingleKey(mods=256, key=107), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='scroll_line_up'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=107), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='scroll_line_up'),
    # scroll_line_down
    KeyDefinition(trigger=SingleKey(mods=256, key=57353), definition='scroll_line_down'),
    # scroll_line_down
-    KeyDefinition(trigger=SingleKey(mods=256, key=106), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='scroll_line_down'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=106), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='scroll_line_down'),
    # scroll_page_up
    KeyDefinition(trigger=SingleKey(mods=256, key=57354), definition='scroll_page_up'),
    # scroll_page_down
@@ -874,33 +874,33 @@ defaults.map = [
    # scroll_end
    KeyDefinition(trigger=SingleKey(mods=256, key=57357), definition='scroll_end'),
    # scroll_to_previous_prompt
-    KeyDefinition(trigger=SingleKey(mods=256, key=122), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='scroll_to_prompt -1'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=122), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='scroll_to_prompt -1'),
    # scroll_to_next_prompt
-    KeyDefinition(trigger=SingleKey(mods=256, key=120), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='scroll_to_prompt 1'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=120), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='scroll_to_prompt 1'),
    # show_scrollback
-    KeyDefinition(trigger=SingleKey(mods=256, key=104), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='show_scrollback'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=104), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='show_scrollback'),
    # show_last_command_output
-    KeyDefinition(trigger=SingleKey(mods=256, key=103), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='show_last_command_output'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=103), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='show_last_command_output'),
    # search_scrollback
    KeyDefinition(trigger=SingleKey(mods=256, key=47), definition='search_scrollback'),
    # new_window
    KeyDefinition(trigger=SingleKey(mods=256, key=57345), definition='new_window'),
    # new_os_window
-    KeyDefinition(trigger=SingleKey(mods=256, key=110), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='new_os_window'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=110), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='new_os_window'),
    # close_window
-    KeyDefinition(trigger=SingleKey(mods=256, key=119), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='close_window'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=119), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='close_window'),
    # next_window
    KeyDefinition(trigger=SingleKey(mods=256, key=93), definition='next_window'),
    # previous_window
    KeyDefinition(trigger=SingleKey(mods=256, key=91), definition='previous_window'),
    # move_window_forward
-    KeyDefinition(trigger=SingleKey(mods=256, key=102), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='move_window_forward'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=102), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='move_window_forward'),
    # move_window_backward
-    KeyDefinition(trigger=SingleKey(mods=256, key=98), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='move_window_backward'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=98), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='move_window_backward'),
    # move_window_to_top
    KeyDefinition(trigger=SingleKey(mods=256, key=96), definition='move_window_to_top'),
    # start_resizing_window
-    KeyDefinition(trigger=SingleKey(mods=256, key=114), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='start_resizing_window'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=114), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='start_resizing_window'),
    # first_window
    KeyDefinition(trigger=SingleKey(mods=256, key=49), definition='first_window'),
    # second_window
@@ -934,17 +934,17 @@ defaults.map = [
    # previous_tab
    KeyDefinition(trigger=SingleKey(mods=5, key=57346), definition='previous_tab'),
    # new_tab
-    KeyDefinition(trigger=SingleKey(mods=256, key=116), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='new_tab'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=116), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='new_tab'),
    # close_tab
-    KeyDefinition(trigger=SingleKey(mods=256, key=113), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='close_tab'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=113), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='close_tab'),
    # move_tab_forward
    KeyDefinition(trigger=SingleKey(mods=256, key=46), definition='move_tab_forward'),
    # move_tab_backward
    KeyDefinition(trigger=SingleKey(mods=256, key=44), definition='move_tab_backward'),
    # set_tab_title
-    KeyDefinition(trigger=SingleKey(mods=258, key=116), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='set_tab_title'),
+    KeyDefinition(trigger=SingleKey(mods=258, key=116), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='set_tab_title'),
    # next_layout
-    KeyDefinition(trigger=SingleKey(mods=256, key=108), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='next_layout'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=108), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='next_layout'),
    # increase_font_size
    KeyDefinition(trigger=SingleKey(mods=256, key=61), definition='change_font_size all +2.0'),
    # increase_font_size
@@ -958,25 +958,25 @@ defaults.map = [
    # reset_font_size
    KeyDefinition(trigger=SingleKey(mods=256, key=57347), definition='change_font_size all 0'),
    # open_url
-    KeyDefinition(trigger=SingleKey(mods=256, key=101), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='open_url_with_hints'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=101), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='open_url_with_hints'),
    # insert_selected_path
-    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=102),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='kitten hints --type path --program -'),
+    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=102),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='kitten hints --type path --program -'),
    # open_selected_path
-    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(mods=1, key=102),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='kitten hints --type path'),
+    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(mods=1, key=102),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='kitten hints --type path'),
    # insert_chosen_file
-    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=99),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='kitten choose-files'),
+    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=99),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='kitten choose-files'),
    # insert_chosen_directory
-    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=100),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='kitten choose-files --mode=dir'),
+    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=100),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='kitten choose-files --mode=dir'),
    # insert_selected_line
-    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=108),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='kitten hints --type line --program -'),
+    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=108),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='kitten hints --type line --program -'),
    # insert_selected_word
-    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=119),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='kitten hints --type word --program -'),
+    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=119),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='kitten hints --type word --program -'),
    # insert_selected_hash
-    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=104),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='kitten hints --type hash --program -'),
+    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=104),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='kitten hints --type hash --program -'),
    # goto_file_line
-    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=110),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='kitten hints --type linenum'),
+    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=110),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='kitten hints --type linenum'),
    # open_selected_hyperlink
-    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=121),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='kitten hints --type hyperlink'),
+    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=112), rest=(SingleKey(key=121),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='kitten hints --type hyperlink'),
    # show_kitty_doc
    KeyDefinition(trigger=SingleKey(mods=256, key=57364), definition='show_kitty_doc overview'),
    # command_palette
@@ -986,19 +986,19 @@ defaults.map = [
    # toggle_maximized
    KeyDefinition(trigger=SingleKey(mods=256, key=57373), definition='toggle_maximized'),
    # input_unicode_character
-    KeyDefinition(trigger=SingleKey(mods=256, key=117), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='kitten unicode_input'),
+    KeyDefinition(trigger=SingleKey(mods=256, key=117), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='kitten unicode_input'),
    # edit_config_file
    KeyDefinition(trigger=SingleKey(mods=256, key=57365), definition='edit_config_file'),
    # kitty_shell
    KeyDefinition(trigger=SingleKey(mods=256, key=57344), definition='kitty_shell window'),
    # increase_background_opacity
-    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=97), rest=(SingleKey(key=109),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='set_background_opacity +0.1'),
+    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=97), rest=(SingleKey(key=109),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='set_background_opacity +0.1'),
    # decrease_background_opacity
-    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=97), rest=(SingleKey(key=108),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='set_background_opacity -0.1'),
+    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=97), rest=(SingleKey(key=108),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='set_background_opacity -0.1'),
    # full_background_opacity
-    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=97), rest=(SingleKey(key=49),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='set_background_opacity 1'),
+    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=97), rest=(SingleKey(key=49),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='set_background_opacity 1'),
    # reset_background_opacity
-    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=97), rest=(SingleKey(key=100),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='set_background_opacity default'),
+    KeyDefinition(is_sequence=True, trigger=SingleKey(mods=256, key=97), rest=(SingleKey(key=100),), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='set_background_opacity default'),
    # reset_terminal
    KeyDefinition(trigger=SingleKey(mods=256, key=57349), definition='clear_terminal reset active'),
    # reload_config_file
@@ -1008,8 +1008,8 @@ defaults.map = [
 ]

 if is_macos:
-    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=99), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='copy_or_noop'))
-    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=118), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='paste_from_clipboard'))
+    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=99), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='copy_or_noop'))
+    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=118), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='paste_from_clipboard'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=10, key=57354), definition='scroll_line_up'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=57352), definition='scroll_line_up'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=10, key=57355), definition='scroll_line_down'))
@@ -1018,11 +1018,11 @@ if is_macos:
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=57355), definition='scroll_page_down'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=57356), definition='scroll_home'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=57357), definition='scroll_end'))
-    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=102), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='search_scrollback'))
+    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=102), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='search_scrollback'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=57345), definition='new_window'))
-    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=110), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='new_os_window'))
-    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=9, key=100), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='close_window'))
-    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=114), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='start_resizing_window'))
+    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=110), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='new_os_window'))
+    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=9, key=100), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='close_window'))
+    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=114), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='start_resizing_window'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=49), definition='first_window'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=50), definition='second_window'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=51), definition='third_window'))
@@ -1034,18 +1034,18 @@ if is_macos:
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=57), definition='ninth_window'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=9, key=93), definition='next_tab'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=9, key=91), definition='previous_tab'))
-    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=116), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='new_tab'))
-    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=119), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='close_tab'))
-    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=9, key=119), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='close_os_window'))
-    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=9, key=105), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='set_tab_title'))
+    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=116), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='new_tab'))
+    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=119), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='close_tab'))
+    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=9, key=119), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='close_os_window'))
+    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=9, key=105), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='set_tab_title'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=43), definition='change_font_size all +2.0'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=61), definition='change_font_size all +2.0'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=9, key=61), definition='change_font_size all +2.0'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=45), definition='change_font_size all -2.0'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=9, key=45), definition='change_font_size all -2.0'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=48), definition='change_font_size all 0'))
-    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=12, key=102), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='toggle_fullscreen'))
-    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=10, key=115), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback='ascii,shifted'), definition='toggle_macos_secure_keyboard_entry'))
+    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=12, key=102), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='toggle_fullscreen'))
+    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=10, key=115), options=KeyMapOptions(when_focus_on='', new_mode='', mode='', on_unknown='beep', on_action='keep', timeout=None, allow_fallback=(KeyFallbackType.shifted, KeyFallbackType.alternate)), definition='toggle_macos_secure_keyboard_entry'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=8, key=96), definition='macos_cycle_through_os_windows'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=9, key=96), definition='macos_cycle_through_os_windows_backwards'))
    defaults.map.append(KeyDefinition(trigger=SingleKey(mods=12, key=32), definition='kitten unicode_input'))
--- a/kitty/options/utils.py
+++ b/kitty/options/utils.py
@@ -1292,7 +1292,7 @@ class LiteralField(Generic[T]):
        val = obj.__dict__.get(self._name)
        if val is None or isinstance(val, LiteralField):
            return self._vals[0]
-        return val
+        return cast(T, val)

    def __set__(self, obj: object, value: str) -> None:
        if value not in self._vals:
@@ -1304,6 +1304,14 @@ OnUnknown = Literal['beep', 'end', 'ignore', 'passthrough']
 OnAction = Literal['keep', 'end']


+class KeyFallbackType(enum.Enum):
+    shifted = 'shifted'
+    alternate = 'alternate'
+
+    def __repr__(self) -> str:
+        return f'KeyFallbackType.{self.value}'
+
+
@dataclass(frozen=True)
 class KeyMapOptions:
    when_focus_on: str = ''
@@ -1312,7 +1320,7 @@ class KeyMapOptions:
    on_unknown: LiteralField[OnUnknown] = LiteralField[OnUnknown](get_args(OnUnknown))
    on_action: LiteralField[OnAction] = LiteralField[OnAction](get_args(OnAction))
    timeout: float | None = None
-    allow_fallback: str = 'shifted'
+    allow_fallback: tuple[KeyFallbackType, ...] = (KeyFallbackType.shifted,)


 default_key_map_options = KeyMapOptions()
@@ -1385,17 +1393,19 @@ key_map_option_converters: defaultdict[str, Callable[[str], Any]] = defaultdict(
 key_map_option_converters['timeout'] = float


-_allowed_fallback_values = frozenset(('shifted', 'ascii'))
-
-
-def _convert_allow_fallback(val: str) -> str:
-    if not val or val == 'none':
-        return ''
-    parts = tuple(x.strip() for x in val.split(','))
-    invalid = set(parts) - _allowed_fallback_values
-    if invalid:
-        raise ValueError(f'allow_fallback values must be a subset of {_allowed_fallback_values}, got: {invalid}')
-    return ','.join(parts)
+def _convert_allow_fallback(val: str) -> tuple[KeyFallbackType, ...]:
+    match val:
+        case '' | 'none':
+            return ()
+        case 'shifted,ascii':
+            return (KeyFallbackType.shifted, KeyFallbackType.alternate)
+        case 'ascii,shifted':
+            return (KeyFallbackType.alternate, KeyFallbackType.shifted)
+        case 'shifted':
+            return (KeyFallbackType.shifted,)
+        case 'ascii':
+            return (KeyFallbackType.alternate,)
+    raise ValueError(f'allow_fallback values must be a subset of shifted, ascii, got: {val}')


 key_map_option_converters['allow_fallback'] = _convert_allow_fallback
--- a/kitty_tests/keys.py
+++ b/kitty_tests/keys.py
@@ -6,6 +6,7 @@ from functools import partial
 import kitty.fast_data_types as defines
 from kitty.key_encoding import EventType, KeyEvent, decode_key_event, encode_key_event
 from kitty.keys import Mappings
+from kitty.options.utils import KeyFallbackType

 from . import BaseTest

@@ -680,7 +681,7 @@ class TestKeys(BaseTest):

    def test_get_shortcut_per_mapping_fallback(self):
        from kitty.keys import get_shortcut
-        from kitty.options.utils import KeyDefinition, KeyMapOptions
+        from kitty.options.utils import KeyDefinition, KeyMapOptions, _convert_allow_fallback

        ctrl = defines.GLFW_MOD_CONTROL
        shift = defines.GLFW_MOD_SHIFT
@@ -688,8 +689,7 @@ class TestKeys(BaseTest):
        latin_c = ord('c')

        def make_kd(definition='test_action', allow_fallback='shifted'):
-            opts = KeyMapOptions()
-            object.__setattr__(opts, 'allow_fallback', allow_fallback)
+            opts = KeyMapOptions(allow_fallback=_convert_allow_fallback(allow_fallback))
            return KeyDefinition(definition=definition, options=opts)

        # non-ASCII key + alternate_key + allow_fallback includes ascii → match
@@ -700,6 +700,18 @@ class TestKeys(BaseTest):
        self.assertIsNotNone(result)
        self.assertIs(result[0], kd_ascii)

+        # sorting by fallback order
+        kd1 = make_kd('ascii', allow_fallback='ascii,shifted')
+        kd2 = make_kd('shifted', allow_fallback='shifted,ascii')
+        keymap = {defines.SingleKey(ctrl, False, latin_c): [kd1, kd2]}
+        ev = defines.KeyEvent(cyrillic_s, 0, latin_c, ctrl)
+        result = get_shortcut(keymap, ev)
+        self.assertEqual(result, [kd1, kd2])
+        keymap = {defines.SingleKey(0, False, latin_c): [kd1, kd2]}
+        ev = defines.KeyEvent(ord('C'), latin_c, 0, shift)
+        result = get_shortcut(keymap, ev)
+        self.assertEqual(result, [kd2, kd1])
+
        # non-ASCII key + alternate_key + allow_fallback='shifted' (no ascii) → no ascii match
        kd_shifted_only = make_kd('copy', allow_fallback='shifted')
        keymap = {defines.SingleKey(ctrl, False, latin_c): [kd_shifted_only]}
@@ -842,34 +854,34 @@ class TestKeys(BaseTest):

        # default: no --allow-fallback → allow_fallback='shifted'
        kd = first_kd('ctrl+c copy_to_clipboard')
-        self.ae(kd.options.allow_fallback, 'shifted')
+        self.ae(kd.options.allow_fallback, (KeyFallbackType.shifted,))

        # --allow-fallback=shifted,ascii
        kd = first_kd('--allow-fallback=shifted,ascii ctrl+c copy_to_clipboard')
-        self.assertIn('shifted', kd.options.allow_fallback)
-        self.assertIn('ascii', kd.options.allow_fallback)
+        self.assertIn(KeyFallbackType.shifted, kd.options.allow_fallback)
+        self.assertIn(KeyFallbackType.alternate, kd.options.allow_fallback)

        # --allow-fallback=ascii (only ascii, no shifted)
        kd = first_kd('--allow-fallback=ascii ctrl+c copy_to_clipboard')
-        self.ae(kd.options.allow_fallback, 'ascii')
-        self.assertNotIn('shifted', kd.options.allow_fallback)
+        self.ae(kd.options.allow_fallback, (KeyFallbackType.alternate,))
+        self.assertNotIn(KeyFallbackType.shifted, kd.options.allow_fallback)

        # --allow-fallback=shifted (explicit, same as default)
        kd = first_kd('--allow-fallback=shifted ctrl+c copy_to_clipboard')
-        self.ae(kd.options.allow_fallback, 'shifted')
+        self.ae(kd.options.allow_fallback, (KeyFallbackType.shifted,))

        # invalid value raises
        self.assertRaises(ValueError, first_kd, '--allow-fallback=bogus ctrl+c copy_to_clipboard')

        # order normalization: ascii,shifted → sorted as ascii,shifted
        kd = first_kd('--allow-fallback=ascii,shifted ctrl+c copy_to_clipboard')
-        self.ae(kd.options.allow_fallback, 'ascii,shifted')
+        self.ae(kd.options.allow_fallback, (KeyFallbackType.alternate, KeyFallbackType.shifted))

        # --allow-fallback=none → empty string (no fallback)
        kd = first_kd('--allow-fallback=none ctrl+c copy_to_clipboard')
-        self.ae(kd.options.allow_fallback, '')
+        self.ae(kd.options.allow_fallback, ())

        # combined with other options
        kd = first_kd('--when-focus-on 1 --allow-fallback=ascii ctrl+c copy_to_clipboard')
-        self.ae(kd.options.allow_fallback, 'ascii')
+        self.ae(kd.options.allow_fallback, (KeyFallbackType.alternate,))
        self.ae(kd.options.when_focus_on, '1')
--- a/tools/config/utils.go
+++ b/tools/config/utils.go
@@ -259,7 +259,7 @@ func validateAllowFallback(value string) error {
 	if value == "" || value == "none" {
 		return nil
 	}
-	for _, part := range strings.Split(value, ",") {
+	for part := range strings.SplitSeq(value, ",") {
 		part = strings.TrimSpace(part)
 		if part != "shifted" && part != "ascii" {
 			return fmt.Errorf("Invalid allow-fallback value %#v, allowed values: shifted, ascii, none", part)