diff --git a/__main__.py b/__main__.py
index 870664f0b..51e4173b6 100644
--- a/__main__.py
+++ b/__main__.py
@@ -13,13 +13,13 @@ def icat(args):
 
 
 def list_fonts(args):
-    from kitty.fonts.list import main
-    main(args)
+    from kitty.fonts.list import main as list_main
+    list_main(args)
 
 
 def remote_control(args):
-    from kitty.remote_control import main
-    main(args)
+    from kitty.remote_control import main as rc_main
+    rc_main(args)
 
 
 def runpy(args):
@@ -35,8 +35,8 @@ def hold(args):
 
 
 def complete(args):
-    from kitty.complete import main
-    main(args[1:], entry_points, namespaced_entry_points)
+    from kitty.complete import main as complete_main
+    complete_main(args[1:], entry_points, namespaced_entry_points)
 
 
 def launch(args):
@@ -92,10 +92,10 @@ def setup_openssl_environment():
     if 'SSL_CERT_FILE' not in os.environ and 'SSL_CERT_DIR' not in os.environ:
         if os.access('/etc/pki/tls/certs/ca-bundle.crt', os.R_OK):
             os.environ['SSL_CERT_FILE'] = '/etc/pki/tls/certs/ca-bundle.crt'
-            sys.kitty_ssl_env_var = 'SSL_CERT_FILE'
+            setattr(sys, 'kitty_ssl_env_var', 'SSL_CERT_FILE')
         elif os.path.isdir('/etc/ssl/certs'):
             os.environ['SSL_CERT_DIR'] = '/etc/ssl/certs'
-            sys.kitty_ssl_env_var = 'SSL_CERT_DIR'
+            setattr(sys, 'kitty_ssl_env_var', 'SSL_CERT_DIR')
 
 
 def main():
@@ -109,8 +109,8 @@ def main():
         elif first_arg.startswith('+'):
             namespaced(['+', first_arg[1:]] + sys.argv[2:])
         else:
-            from kitty.main import main
-            main()
+            from kitty.main import main as kitty_main
+            kitty_main()
     else:
         func(sys.argv[1:])
 
diff --git a/gen-wcwidth.py b/gen-wcwidth.py
index 35a7945a3..fd2d5c3e4 100755
--- a/gen-wcwidth.py
+++ b/gen-wcwidth.py
@@ -12,7 +12,9 @@ from functools import partial
 from html.entities import html5
 from itertools import groupby
 from operator import itemgetter
-from typing import DefaultDict, Dict, Set
+from typing import (
+    DefaultDict, Dict, Generator, Iterable, List, Optional, Set, Tuple, Union
+)
 from urllib.request import urlopen
 
 os.chdir(os.path.dirname(os.path.abspath(__file__)))
@@ -44,8 +46,8 @@ def get_data(fname, folder='UCD'):
 
 # Map of class names to set of codepoints in class
 class_maps: Dict[str, Set[int]] = {}
-all_symbols = set()
-name_map = {}
+all_symbols: Set[int] = set()
+name_map: Dict[int, str] = {}
 word_search_map: DefaultDict[str, Set[int]] = defaultdict(set)
 zwj = 0x200d
 marks = set(emoji_skin_tone_modifiers) | {zwj}
@@ -60,7 +62,7 @@ def parse_ucd():
         if len(w) > 1:
             word_search_map[w.lower()].add(c)
 
-    first = None
+    first: Optional[int] = None
     for word, c in html5.items():
         if len(c) == 1:
             add_word(word.rstrip(';'), ord(c))
@@ -78,7 +80,7 @@ def parse_ucd():
         category = parts[2]
         s = class_maps.setdefault(category, set())
         desc = parts[1]
-        codepoints = (codepoint,)
+        codepoints: Union[Tuple[int, ...], Iterable[int]] = (codepoint,)
         if first is None:
             if desc.endswith(', First>'):
                 first = codepoint
@@ -104,8 +106,8 @@ def split_two(line):
     spec, rest = line.split(';', 1)
     spec, rest = spec.strip(), rest.strip().split(' ', 1)[0].strip()
     if '..' in spec:
-        chars = tuple(map(lambda x: int(x, 16), filter(None, spec.split('.'))))
-        chars = set(range(chars[0], chars[1] + 1))
+        chars_ = tuple(map(lambda x: int(x, 16), filter(None, spec.split('.'))))
+        chars = set(range(chars_[0], chars_[1] + 1))
     else:
         chars = {int(spec, 16)}
     return chars, rest
@@ -137,7 +139,7 @@ ambiguous: Set[int] = set()
 
 def parse_eaw():
     global doublewidth, ambiguous
-    seen = set()
+    seen: Set[int] = set()
     for line in get_data('ucd/EastAsianWidth.txt'):
         chars, eaw = split_two(line)
         if eaw == 'A':
@@ -153,7 +155,7 @@ def parse_eaw():
     doublewidth |= set(range(0x30000, 0x3FFFD + 1)) - seen
 
 
-def get_ranges(items):
+def get_ranges(items: List[int]) -> Generator[Union[int, Tuple[int, int]], None, None]:
     items.sort()
     for k, g in groupby(enumerate(items), lambda m: m[0]-m[1]):
         group = tuple(map(itemgetter(1), g))
@@ -221,7 +223,7 @@ def gen_emoji():
 
 def category_test(name, p, classes, comment, static=False, extra_chars=frozenset(), exclude=frozenset()):
     static = 'static inline ' if static else ''
-    chars = set()
+    chars: Set[int] = set()
     for c in classes:
         chars |= class_maps[c]
     chars |= extra_chars
@@ -252,7 +254,7 @@ def codepoint_to_mark_map(p, mark_map):
 
 
 def classes_to_regex(classes, exclude=''):
-    chars = set()
+    chars: Set[int] = set()
     for c in classes:
         chars |= class_maps[c]
     for c in map(ord, exclude):
@@ -300,7 +302,9 @@ def gen_ucd():
         p('}\n')
         with open('kitty/unicode-data.h') as f:
             unicode_data = f.read()
-        expected = int(re.search(r'^#define VS15 (\d+)', unicode_data, re.M).group(1))
+        m = re.search(r'^#define VS15 (\d+)', unicode_data, re.M)
+        if m is not None:
+            expected = int(m.group(1))
         if rmap[0xfe0e] != expected:
             raise ValueError('The mark for 0xfe0e has changed, you have to update VS15 to {} and VS16 to {} in unicode-data.h'.format(
                 rmap[0xfe0e], rmap[0xfe0f]
@@ -364,7 +368,7 @@ def gen_names():
 
         # The trie
         p(f'typedef struct {{ uint32_t children_offset; uint32_t match_offset; }} word_trie;\n')
-        all_trie_nodes = []
+        all_trie_nodes: List['TrieNode'] = []
 
         class TrieNode:
 
@@ -411,7 +415,7 @@ def gen_names():
 
 
 def gen_wcwidth():
-    seen = set()
+    seen: Set[int] = set()
 
     def add(p, comment, chars_, ret):
         chars = chars_ - seen
diff --git a/glfw/glfw.py b/glfw/glfw.py
index 4e8aae0e4..d737b191b 100755
--- a/glfw/glfw.py
+++ b/glfw/glfw.py
@@ -46,8 +46,8 @@ def init_env(env, pkg_config, at_least_version, test_compile, module='x11'):
 
     elif module == 'cocoa':
         ans.cppflags.append('-DGL_SILENCE_DEPRECATION')
-        for f in 'Cocoa IOKit CoreFoundation CoreVideo'.split():
-            ans.ldpaths.extend(('-framework', f))
+        for f_ in 'Cocoa IOKit CoreFoundation CoreVideo'.split():
+            ans.ldpaths.extend(('-framework', f_))
 
     elif module == 'wayland':
         at_least_version('wayland-protocols', *sinfo['wayland_protocols'])
diff --git a/kitty/client.py b/kitty/client.py
index 498268ae3..4b844f8fa 100644
--- a/kitty/client.py
+++ b/kitty/client.py
@@ -127,16 +127,16 @@ def screen_manipulate_title_stack(op, which):
     write(CSI + '%d;%dt' % (op, which))
 
 
-def report_device_attributes(mode, char):
+def report_device_attributes(mode: int, char: int) -> None:
     x = CSI
     if char:
-        x += ord(char)
+        x += chr(char)
     if mode:
         x += str(mode)
     write(CSI + x + 'c')
 
 
-def write_osc(code, string=''):
+def write_osc(code: int, string='') -> None:
     if string:
         string = ';' + string
     write(OSC + str(code) + string + '\x07')
diff --git a/kitty/fonts/__init__.py b/kitty/fonts/__init__.py
index e69de29bb..88ec07c94 100644
--- a/kitty/fonts/__init__.py
+++ b/kitty/fonts/__init__.py
@@ -0,0 +1,11 @@
+try:
+    from typing import TypedDict
+except ImportError:
+    TypedDict = dict
+
+
+class ListedFont(TypedDict):
+    family: str
+    full_name: str
+    postscript_name: str
+    is_monospace: bool
diff --git a/kitty/fonts/core_text.py b/kitty/fonts/core_text.py
index 7339c06c8..cc871f1ad 100644
--- a/kitty/fonts/core_text.py
+++ b/kitty/fonts/core_text.py
@@ -3,10 +3,13 @@
 # License: GPL v3 Copyright: 2017, Kovid Goyal <kovid at kovidgoyal.net>
 
 import re
+from typing import Generator
 
 from kitty.fast_data_types import coretext_all_fonts
 from kitty.utils import log_error
 
+from . import ListedFont
+
 attr_map = {(False, False): 'font_family',
             (True, False): 'bold_font',
             (False, True): 'italic_font',
@@ -32,7 +35,7 @@ def all_fonts_map():
     return ans
 
 
-def list_fonts():
+def list_fonts() -> Generator[ListedFont, None, None]:
     for fd in coretext_all_fonts():
         f = fd['family']
         if f:
diff --git a/kitty/fonts/fontconfig.py b/kitty/fonts/fontconfig.py
index 8a004d33b..ad30a68c5 100644
--- a/kitty/fonts/fontconfig.py
+++ b/kitty/fonts/fontconfig.py
@@ -4,12 +4,15 @@
 
 import re
 from functools import lru_cache
+from typing import Generator
 
 from kitty.fast_data_types import (
-    FC_SLANT_ITALIC, FC_SLANT_ROMAN, FC_WEIGHT_BOLD, FC_WEIGHT_REGULAR,
-    fc_list, fc_match as fc_match_impl, FC_DUAL, FC_MONO
+    FC_DUAL, FC_MONO, FC_SLANT_ITALIC, FC_SLANT_ROMAN, FC_WEIGHT_BOLD,
+    FC_WEIGHT_REGULAR, fc_list, fc_match as fc_match_impl
 )
 
+from . import ListedFont
+
 attr_map = {(False, False): 'font_family',
             (True, False): 'bold_font',
             (False, True): 'italic_font',
@@ -39,7 +42,7 @@ def all_fonts_map(monospaced=True):
     return create_font_map(ans)
 
 
-def list_fonts():
+def list_fonts() -> Generator[ListedFont, None, None]:
     for fd in fc_list():
         f = fd.get('family')
         if f:
diff --git a/kitty/fonts/list.py b/kitty/fonts/list.py
index ef6947812..65be4e98d 100644
--- a/kitty/fonts/list.py
+++ b/kitty/fonts/list.py
@@ -4,6 +4,7 @@
 
 import sys
 from kitty.constants import is_macos
+from typing import Sequence
 
 if is_macos:
     from .core_text import list_fonts
@@ -19,7 +20,7 @@ def create_family_groups(monospaced=True):
     return g
 
 
-def main(argv):
+def main(argv: Sequence[str]) -> None:
     psnames = '--psnames' in argv
     isatty = sys.stdout.isatty()
     groups = create_family_groups()