diff --git a/mesonbuild/cmake/common.py b/mesonbuild/cmake/common.py
index 415937ee9..aa0bbbf0b 100644
--- a/mesonbuild/cmake/common.py
+++ b/mesonbuild/cmake/common.py
@@ -209,7 +209,7 @@ class CMakeTarget:
         self.link_lang_flags = _flags_to_list(data.get('linkLanguageFlags', ''))
         # self.link_path = Path(data.get('linkPath', ''))
         self.type: str = data.get('type', 'EXECUTABLE')
-        # self.is_generator_provided = data.get('isGeneratorProvided', False)         # type: bool
+        # self.is_generator_provided: bool = data.get('isGeneratorProvided', False)
         self.files: T.List[CMakeFileGroup] = []
 
         for i in data.get('fileGroups', []):
diff --git a/run_project_tests.py b/run_project_tests.py
index 7413c6843..7ff164086 100755
--- a/run_project_tests.py
+++ b/run_project_tests.py
@@ -134,11 +134,11 @@ class InstalledFile:
         self.path = raw['file']
         self.typ = raw['type']
         self.platform = raw.get('platform', None)
-        self.language = raw.get('language', 'c')  # type: str
+        self.language = raw.get('language', 'c')
 
-        version = raw.get('version', '')  # type: str
+        version = raw.get('version', '')
         if version:
-            self.version = version.split('.')  # type: T.List[str]
+            self.version = version.split('.')
         else:
             # split on '' will return [''], we want an empty list though
             self.version = []
@@ -280,9 +280,9 @@ class TestDef:
         self.args = args
         self.skip = skip
         self.env = os.environ.copy()
-        self.installed_files = []  # type: T.List[InstalledFile]
-        self.do_not_set_opts = []  # type: T.List[str]
-        self.stdout = [] # type: T.List[T.Dict[str, str]]
+        self.installed_files: T.List[InstalledFile] = []
+        self.do_not_set_opts: T.List[str] = []
+        self.stdout: T.List[T.Dict[str, str]] = []
         self.skip_category = skip_category
         self.skip_expected = False
 
@@ -399,7 +399,7 @@ def platform_fix_name(fname: str, canonical_compiler: str, env: environment.Envi
 
 def validate_install(test: TestDef, installdir: Path, env: environment.Environment) -> str:
     ret_msg = ''
-    expected_raw = []  # type: T.List[Path]
+    expected_raw: T.List[Path] = []
     for i in test.installed_files:
         try:
             expected_raw += i.get_paths(host_c_compiler, env, installdir)
@@ -828,7 +828,7 @@ def load_test_json(t: TestDef, stdout_mandatory: bool, skip_category: bool = Fal
         test_def = json.loads(test_def_file.read_text(encoding='utf-8'))
 
     # Handle additional environment variables
-    env = {}  # type: T.Dict[str, str]
+    env: T.Dict[str, str] = {}
     if 'env' in test_def:
         assert isinstance(test_def['env'], dict)
         env = test_def['env']
@@ -838,7 +838,7 @@ def load_test_json(t: TestDef, stdout_mandatory: bool, skip_category: bool = Fal
             env[key] = val
 
     # Handle installed files
-    installed = []  # type: T.List[InstalledFile]
+    installed: T.List[InstalledFile] = []
     if 'installed' in test_def:
         installed = [InstalledFile(x) for x in test_def['installed']]
 
@@ -848,7 +848,7 @@ def load_test_json(t: TestDef, stdout_mandatory: bool, skip_category: bool = Fal
         raise RuntimeError(f"{test_def_file} must contain a non-empty stdout key")
 
     # Handle the do_not_set_opts list
-    do_not_set_opts = test_def.get('do_not_set_opts', [])  # type: T.List[str]
+    do_not_set_opts: T.List[str] = test_def.get('do_not_set_opts', [])
 
     (t.skip, t.skip_expected) = _skip_keys(test_def)
 
@@ -872,12 +872,12 @@ def load_test_json(t: TestDef, stdout_mandatory: bool, skip_category: bool = Fal
     new_opt_list: T.List[T.List[T.Tuple[str, str, bool, bool]]]
 
     # 'matrix; entry is present, so build multiple tests from matrix definition
-    opt_list = []  # type: T.List[T.List[T.Tuple[str, str, bool, bool]]]
+    opt_list: T.List[T.List[T.Tuple[str, str, bool, bool]]] = []
     matrix = test_def['matrix']
     assert "options" in matrix
     for key, val in matrix["options"].items():
         assert isinstance(val, list)
-        tmp_opts = []  # type: T.List[T.Tuple[str, str, bool, bool]]
+        tmp_opts: T.List[T.Tuple[str, str, bool, bool]] = []
         for i in val:
             assert isinstance(i, dict)
             assert "val" in i
diff --git a/tools/cmake2meson.py b/tools/cmake2meson.py
index a12d9cf1f..7889cd825 100755
--- a/tools/cmake2meson.py
+++ b/tools/cmake2meson.py
@@ -119,7 +119,7 @@ class Parser:
         return Statement(cur.value, args)
 
     def arguments(self) -> T.List[T.Union[Token, T.Any]]:
-        args = []  # type: T.List[T.Union[Token, T.Any]]
+        args: T.List[T.Union[Token, T.Any]] = []
         if self.accept('lparen'):
             args.append(self.arguments())
             self.expect('rparen')
@@ -159,7 +159,7 @@ class Converter:
         self.cmake_root = Path(cmake_root).expanduser()
         self.indent_unit = '  '
         self.indent_level = 0
-        self.options = []  # type: T.List[tuple]
+        self.options: T.List[T.Tuple[str, str, T.Optional[str]]] = []
 
     def convert_args(self, args: T.List[Token], as_array: bool = True) -> str:
         res = []
diff --git a/unittests/internaltests.py b/unittests/internaltests.py
index eb3b1717a..1c55b2976 100644
--- a/unittests/internaltests.py
+++ b/unittests/internaltests.py
@@ -1020,7 +1020,7 @@ class InternalTests(unittest.TestCase):
 
         schema = json.loads(Path('data/test.schema.json').read_text(encoding='utf-8'))
 
-        errors = []  # type: T.Tuple[str, Exception]
+        errors: T.List[T.Tuple[Path, Exception]] = []
         for p in Path('test cases').glob('**/test.json'):
             try:
                 validate(json.loads(p.read_text(encoding='utf-8')), schema=schema)