diff --git a/cxxheaderparser/dump.py b/cxxheaderparser/dump.py
index f9e194b..daa1e5c 100644
--- a/cxxheaderparser/dump.py
+++ b/cxxheaderparser/dump.py
@@ -9,7 +9,7 @@ from .options import ParserOptions
 from .simple import parse_file
 
 
-def dumpmain():
+def dumpmain() -> None:
 
     parser = argparse.ArgumentParser()
     parser.add_argument("header")
diff --git a/cxxheaderparser/gentest.py b/cxxheaderparser/gentest.py
index 19bca76..ff30512 100644
--- a/cxxheaderparser/gentest.py
+++ b/cxxheaderparser/gentest.py
@@ -46,7 +46,7 @@ def nondefault_repr(data):
     return _inner_repr(data)
 
 
-def gentest(infile: str, name: str, outfile: str, verbose: bool):
+def gentest(infile: str, name: str, outfile: str, verbose: bool) -> None:
     # Goal is to allow making a unit test as easy as running this dumper
     # on a file and copy/pasting this into a test
 
@@ -64,7 +64,7 @@ def gentest(infile: str, name: str, outfile: str, verbose: bool):
     stmt = inspect.cleandoc(
         f'''
     
-        def test_{name}():
+        def test_{name}() -> None:
             content = """
               {content}
             """
diff --git a/cxxheaderparser/parser.py b/cxxheaderparser/parser.py
index dec6e33..5b7a7c2 100644
--- a/cxxheaderparser/parser.py
+++ b/cxxheaderparser/parser.py
@@ -544,7 +544,7 @@ class CxxParser:
 
         return TemplateDecl(params)
 
-    def _parse_template(self, tok: LexToken, doxygen: typing.Optional[str]):
+    def _parse_template(self, tok: LexToken, doxygen: typing.Optional[str]) -> None:
 
         template = self._parse_template_decl()
 
@@ -2128,7 +2128,7 @@ class CxxParser:
         template: typing.Optional[TemplateDecl],
         is_typedef: bool,
         is_friend: bool,
-    ):
+    ) -> None:
         tok = self._next_token_must_be("operator")
 
         if is_typedef:
diff --git a/cxxheaderparser/parserstate.py b/cxxheaderparser/parserstate.py
index 0f0722b..89c892d 100644
--- a/cxxheaderparser/parserstate.py
+++ b/cxxheaderparser/parserstate.py
@@ -57,7 +57,7 @@ class ExternBlockState(State):
         super().__init__(parent)
         self.linkage = linkage
 
-    def _finish(self, visitor: "CxxVisitor"):
+    def _finish(self, visitor: "CxxVisitor") -> None:
         visitor.on_extern_block_end(self)
 
 
diff --git a/cxxheaderparser/simple.py b/cxxheaderparser/simple.py
index 4ef6f24..0e5d086 100644
--- a/cxxheaderparser/simple.py
+++ b/cxxheaderparser/simple.py
@@ -185,7 +185,7 @@ class SimpleCxxVisitor:
     namespace: NamespaceScope
     block: Block
 
-    def __init__(self):
+    def __init__(self) -> None:
         self.namespace = NamespaceScope("")
         self.block = self.namespace
 
@@ -259,7 +259,7 @@ class SimpleCxxVisitor:
         ns = UsingNamespace("::".join(namespace))
         self.block.using_ns.append(ns)
 
-    def on_using_alias(self, state: State, using: UsingAlias):
+    def on_using_alias(self, state: State, using: UsingAlias) -> None:
         self.block.using_alias.append(using)
 
     def on_using_declaration(self, state: State, using: UsingDecl) -> None:
@@ -288,7 +288,7 @@ class SimpleCxxVisitor:
     def on_class_method(self, state: ClassBlockState, method: Method) -> None:
         self.block.methods.append(method)
 
-    def on_class_friend(self, state: ClassBlockState, friend: FriendDecl):
+    def on_class_friend(self, state: ClassBlockState, friend: FriendDecl) -> None:
         self.block.friends.append(friend)
 
     def on_class_end(self, state: ClassBlockState) -> None:
diff --git a/cxxheaderparser/visitor.py b/cxxheaderparser/visitor.py
index 8afeb45..828af5a 100644
--- a/cxxheaderparser/visitor.py
+++ b/cxxheaderparser/visitor.py
@@ -119,7 +119,7 @@ class CxxVisitor(Protocol):
             using namespace std;
         """
 
-    def on_using_alias(self, state: State, using: UsingAlias):
+    def on_using_alias(self, state: State, using: UsingAlias) -> None:
         """
         .. code-block:: c++
 
@@ -171,7 +171,7 @@ class CxxVisitor(Protocol):
         Called when a field of a class is encountered
         """
 
-    def on_class_friend(self, state: ClassBlockState, friend: FriendDecl):
+    def on_class_friend(self, state: ClassBlockState, friend: FriendDecl) -> None:
         """
         Called when a friend declaration is encountered
         """
diff --git a/tests/test_attributes.py b/tests/test_attributes.py
index 122bada..4f1da84 100644
--- a/tests/test_attributes.py
+++ b/tests/test_attributes.py
@@ -28,7 +28,7 @@ from cxxheaderparser.simple import (
 )
 
 
-def test_attributes_everywhere():
+def test_attributes_everywhere() -> None:
     # TODO: someday we'll actually support storing attributes,
     #       but for now just make sure they don't get in the way
 
@@ -124,7 +124,7 @@ def test_attributes_everywhere():
     )
 
 
-def test_attributes_gcc_enum_packed():
+def test_attributes_gcc_enum_packed() -> None:
     content = """
       enum Wheat {
         w1,
@@ -152,7 +152,7 @@ def test_attributes_gcc_enum_packed():
     )
 
 
-def test_friendly_declspec():
+def test_friendly_declspec() -> None:
     content = """
       struct D {
           friend __declspec(dllexport) void my_friend();
@@ -205,7 +205,7 @@ def test_friendly_declspec():
     )
 
 
-def test_declspec_template():
+def test_declspec_template() -> None:
     content = """
       template <class T2>
       __declspec(deprecated("message"))
diff --git a/tests/test_class.py b/tests/test_class.py
index a932589..599afb0 100644
--- a/tests/test_class.py
+++ b/tests/test_class.py
@@ -38,7 +38,7 @@ from cxxheaderparser.simple import (
 )
 
 
-def test_class_member_spec_1():
+def test_class_member_spec_1() -> None:
     content = """
       class S {
         int d1;                   // non-static data member
@@ -266,7 +266,7 @@ def test_class_member_spec_1():
     )
 
 
-def test_class_member_spec_2():
+def test_class_member_spec_2() -> None:
     content = """
       class M {
         std::size_t C;
@@ -437,7 +437,7 @@ def test_class_member_spec_2():
     )
 
 
-def test_class_member_spec_3():
+def test_class_member_spec_3() -> None:
     content = """
       class S {
       public:
@@ -513,7 +513,7 @@ def test_class_member_spec_3():
     )
 
 
-def test_class_using():
+def test_class_using() -> None:
     content = """
       class Base {
       protected:
@@ -586,7 +586,7 @@ def test_class_using():
     )
 
 
-def test_class_member_spec_6():
+def test_class_member_spec_6() -> None:
     content = """
       struct S {
         template<typename T>
@@ -688,7 +688,7 @@ def test_class_member_spec_6():
     )
 
 
-def test_class_fn_default_params():
+def test_class_fn_default_params() -> None:
     content = """
       // clang-format off
       class Hen
@@ -796,7 +796,7 @@ def test_class_fn_default_params():
     )
 
 
-def test_class_fn_inline_virtual():
+def test_class_fn_inline_virtual() -> None:
     content = """
       class B {
       public:
@@ -834,7 +834,7 @@ def test_class_fn_inline_virtual():
     )
 
 
-def test_class_fn_pure_virtual_const():
+def test_class_fn_pure_virtual_const() -> None:
     content = """
       class StoneClass {
         virtual int getNum2() const = 0;
@@ -884,7 +884,7 @@ def test_class_fn_pure_virtual_const():
     )
 
 
-def test_class_fn_return_global_ns():
+def test_class_fn_return_global_ns() -> None:
     content = """
       struct Avacado {
         uint8_t foo() { return 4; }
@@ -935,7 +935,7 @@ def test_class_fn_return_global_ns():
     )
 
 
-def test_class_ns_class():
+def test_class_ns_class() -> None:
     content = """
       namespace ns {
         class N;
@@ -976,7 +976,7 @@ def test_class_ns_class():
     )
 
 
-def test_class_ns_w_base():
+def test_class_ns_w_base() -> None:
     content = """
       class Herb::Cilantro : public Plant {};
     """
@@ -1007,7 +1007,7 @@ def test_class_ns_w_base():
     )
 
 
-def test_class_inner_class():
+def test_class_inner_class() -> None:
     content = """
       class C {
         class Inner {};
@@ -1042,7 +1042,7 @@ def test_class_inner_class():
     )
 
 
-def test_class_inner_fwd_class():
+def test_class_inner_fwd_class() -> None:
     content = """
       class C {
         class N;
@@ -1083,7 +1083,7 @@ def test_class_inner_fwd_class():
     )
 
 
-def test_class_inner_var_access():
+def test_class_inner_var_access() -> None:
     content = """
       class Bug_3488053 {
       public:
@@ -1133,7 +1133,7 @@ def test_class_inner_var_access():
     )
 
 
-def test_class_ns_and_inner():
+def test_class_ns_and_inner() -> None:
     content = """
       namespace RoosterNamespace {
       class RoosterOuterClass {
@@ -1275,7 +1275,7 @@ def test_class_ns_and_inner():
     )
 
 
-def test_class_struct_access():
+def test_class_struct_access() -> None:
     content = """
       struct SampleStruct {
         unsigned int meth();
@@ -1325,7 +1325,7 @@ def test_class_struct_access():
     )
 
 
-def test_class_volatile_move_deleted_fn():
+def test_class_volatile_move_deleted_fn() -> None:
     content = """
       struct C {
         void foo() volatile && = delete;
@@ -1363,7 +1363,7 @@ def test_class_volatile_move_deleted_fn():
     )
 
 
-def test_class_bitfield_1():
+def test_class_bitfield_1() -> None:
     content = """
       struct S {
         // will usually occupy 2 bytes:
@@ -1441,7 +1441,7 @@ def test_class_bitfield_1():
     )
 
 
-def test_class_bitfield_2():
+def test_class_bitfield_2() -> None:
     content = """
       struct HAL_ControlWord {
         int x : 1;
@@ -1521,7 +1521,7 @@ def test_class_bitfield_2():
     )
 
 
-def test_class_anon_struct_as_globalvar():
+def test_class_anon_struct_as_globalvar() -> None:
     content = """
       struct {
         int m;
@@ -1575,7 +1575,7 @@ def test_class_anon_struct_as_globalvar():
     )
 
 
-def test_class_anon_struct_as_classvar():
+def test_class_anon_struct_as_classvar() -> None:
     content = """
       struct AnonHolderClass {
         struct {
@@ -1633,7 +1633,7 @@ def test_class_anon_struct_as_classvar():
     )
 
 
-def test_initializer_with_initializer_list_1():
+def test_initializer_with_initializer_list_1() -> None:
     content = """
       struct ComplexInit : SomeBase {
         ComplexInit(int i) : m_stuff{i, 2} { auto i = something(); }
@@ -1730,7 +1730,7 @@ def test_initializer_with_initializer_list_1():
     )
 
 
-def test_initializer_with_initializer_list_2():
+def test_initializer_with_initializer_list_2() -> None:
     content = """
       template <typename T> class future final {
       public:
@@ -1804,7 +1804,7 @@ def test_initializer_with_initializer_list_2():
     )
 
 
-def test_class_with_arrays():
+def test_class_with_arrays() -> None:
     content = """
       const int MAX_ITEM = 7;
       class Bird {
@@ -1875,7 +1875,7 @@ def test_class_with_arrays():
     )
 
 
-def test_class_fn_inline_impl():
+def test_class_fn_inline_impl() -> None:
     content = """
       class Monkey {
       private:
@@ -1929,7 +1929,7 @@ def test_class_fn_inline_impl():
     )
 
 
-def test_class_fn_virtual_final_override():
+def test_class_fn_virtual_final_override() -> None:
     content = """
       struct Lemon {
         virtual void foo() final;
@@ -2020,7 +2020,7 @@ def test_class_fn_virtual_final_override():
     )
 
 
-def test_class_fn_return_class():
+def test_class_fn_return_class() -> None:
     content = """
       class Peach {
         int abc;
@@ -2144,7 +2144,7 @@ def test_class_fn_return_class():
     )
 
 
-def test_class_fn_template_impl():
+def test_class_fn_template_impl() -> None:
     content = """
       class Owl {
       private:
@@ -2231,7 +2231,7 @@ def test_class_fn_template_impl():
     )
 
 
-def test_class_fn_inline_template_impl():
+def test_class_fn_inline_template_impl() -> None:
     content = """
       class Chicken {
         template <typename T> static T Get();
@@ -2287,7 +2287,7 @@ def test_class_fn_inline_template_impl():
     )
 
 
-def test_class_fn_explicit_constructors():
+def test_class_fn_explicit_constructors() -> None:
     content = """
       class Lizzard {
         Lizzard();
@@ -2337,7 +2337,7 @@ def test_class_fn_explicit_constructors():
     )
 
 
-def test_class_fn_default_constructor():
+def test_class_fn_default_constructor() -> None:
     content = """
       class DefaultConstDest {
       public:
@@ -2374,7 +2374,7 @@ def test_class_fn_default_constructor():
     )
 
 
-def test_class_fn_delete_constructor():
+def test_class_fn_delete_constructor() -> None:
     content = """
       class A {
       public:
@@ -2408,7 +2408,7 @@ def test_class_fn_delete_constructor():
     )
 
 
-def test_class_multi_vars():
+def test_class_multi_vars() -> None:
     content = """
       class Grape {
       public:
@@ -2580,7 +2580,7 @@ def test_class_multi_vars():
     )
 
 
-def test_class_static_const_var_expr():
+def test_class_static_const_var_expr() -> None:
     content = """
       class PandaClass {
         static const int CONST_A = (1 << 7) - 1;
@@ -2648,7 +2648,7 @@ def test_class_static_const_var_expr():
     )
 
 
-def test_class_fwd_struct():
+def test_class_fwd_struct() -> None:
     content = """
       class PotatoClass {
         struct FwdStruct;
@@ -2720,7 +2720,7 @@ def test_class_fwd_struct():
     )
 
 
-def test_class_multi_array():
+def test_class_multi_array() -> None:
     content = """
       struct Picture {
         char name[25];
@@ -2777,7 +2777,7 @@ def test_class_multi_array():
     )
 
 
-def test_class_noexcept():
+def test_class_noexcept() -> None:
     content = """
       struct Grackle {
         void no_noexcept();
@@ -2919,7 +2919,7 @@ def test_class_noexcept():
     )
 
 
-def test_class_volatile():
+def test_class_volatile() -> None:
     content = """
       class Foo
       {
@@ -2960,7 +2960,7 @@ def test_class_volatile():
     )
 
 
-def test_class_mutable():
+def test_class_mutable() -> None:
     content = """
       class Foo
       {
diff --git a/tests/test_class_base.py b/tests/test_class_base.py
index 543f226..4e7a840 100644
--- a/tests/test_class_base.py
+++ b/tests/test_class_base.py
@@ -21,7 +21,7 @@ from cxxheaderparser.simple import (
 )
 
 
-def test_class_private_base():
+def test_class_private_base() -> None:
     content = """
       namespace Citrus
       {
@@ -108,7 +108,7 @@ def test_class_private_base():
     )
 
 
-def test_class_virtual_base():
+def test_class_virtual_base() -> None:
     content = """
       class BaseMangoClass {};
       class MangoClass : virtual public BaseMangoClass {};
@@ -148,7 +148,7 @@ def test_class_virtual_base():
     )
 
 
-def test_class_multiple_base_with_virtual():
+def test_class_multiple_base_with_virtual() -> None:
     content = """
       class BlueJay : public Bird, public virtual Food {
       public:
@@ -193,7 +193,7 @@ def test_class_multiple_base_with_virtual():
     )
 
 
-def test_class_base_specialized():
+def test_class_base_specialized() -> None:
     content = """
       class Pea : public Vegetable<Green> {
         int i;
diff --git a/tests/test_doxygen.py b/tests/test_doxygen.py
index 7bc1472..97cbd07 100644
--- a/tests/test_doxygen.py
+++ b/tests/test_doxygen.py
@@ -38,7 +38,7 @@ from cxxheaderparser.simple import (
 )
 
 
-def test_doxygen_class():
+def test_doxygen_class() -> None:
     content = """
       // clang-format off
       
@@ -107,7 +107,7 @@ def test_doxygen_class():
     )
 
 
-def test_doxygen_class_template():
+def test_doxygen_class_template() -> None:
     content = """
       // clang-format off
       
@@ -136,7 +136,7 @@ def test_doxygen_class_template():
     )
 
 
-def test_doxygen_enum():
+def test_doxygen_enum() -> None:
     content = """
       // clang-format off
       
@@ -182,7 +182,7 @@ def test_doxygen_enum():
     )
 
 
-def test_doxygen_fn_3slash():
+def test_doxygen_fn_3slash() -> None:
     content = """
       // clang-format off
       
@@ -209,7 +209,7 @@ def test_doxygen_fn_3slash():
     )
 
 
-def test_doxygen_fn_cstyle():
+def test_doxygen_fn_cstyle() -> None:
     content = """
       // clang-format off
       
@@ -238,7 +238,7 @@ def test_doxygen_fn_cstyle():
     )
 
 
-def test_doxygen_var_above():
+def test_doxygen_var_above() -> None:
     content = """
       // clang-format off
       
@@ -267,7 +267,7 @@ def test_doxygen_var_above():
     )
 
 
-def test_doxygen_var_after():
+def test_doxygen_var_after() -> None:
     content = """
       // clang-format off
       
diff --git a/tests/test_enum.py b/tests/test_enum.py
index 8b1953f..b2fa002 100644
--- a/tests/test_enum.py
+++ b/tests/test_enum.py
@@ -25,7 +25,7 @@ from cxxheaderparser.simple import (
 )
 
 
-def test_basic_enum():
+def test_basic_enum() -> None:
     content = """
       enum Foo {
         A,
@@ -48,7 +48,7 @@ def test_basic_enum():
     )
 
 
-def test_enum_w_expr():
+def test_enum_w_expr() -> None:
     content = """
       enum Foo {
         A = (1 / 2),
@@ -85,7 +85,7 @@ def test_enum_w_expr():
     )
 
 
-def test_enum_w_multiline_expr():
+def test_enum_w_multiline_expr() -> None:
     content = r"""
       // clang-format off
       enum Author
@@ -139,7 +139,7 @@ def test_enum_w_multiline_expr():
     )
 
 
-def test_basic_enum_class():
+def test_basic_enum_class() -> None:
     content = """
       enum class BE { BEX };
     """
@@ -159,7 +159,7 @@ def test_basic_enum_class():
     )
 
 
-def test_basic_enum_struct():
+def test_basic_enum_struct() -> None:
     content = """
       enum struct BE { BEX };
     """
@@ -179,7 +179,7 @@ def test_basic_enum_struct():
     )
 
 
-def test_enum_base():
+def test_enum_base() -> None:
     content = """
       enum class E : int {};
     """
@@ -203,7 +203,7 @@ def test_enum_base():
 # instances
 
 
-def test_enum_instance_1():
+def test_enum_instance_1() -> None:
     content = """
       enum class BE { BEX } be1;
     """
@@ -233,7 +233,7 @@ def test_enum_instance_1():
     )
 
 
-def test_enum_instance_2():
+def test_enum_instance_2() -> None:
     content = """
       enum class BE { BEX } be1, *be2;
     """
@@ -277,7 +277,7 @@ def test_enum_instance_2():
 # bases in namespaces
 
 
-def test_enum_base_in_ns():
+def test_enum_base_in_ns() -> None:
     content = """
       namespace EN {
       typedef int EINT;
@@ -322,7 +322,7 @@ def test_enum_base_in_ns():
 # forward declarations
 
 
-def test_enum_fwd():
+def test_enum_fwd() -> None:
     content = """
       enum class BE1;
       enum class BE2 : EN::EINT;
@@ -350,7 +350,7 @@ def test_enum_fwd():
     )
 
 
-def test_enum_private_in_class():
+def test_enum_private_in_class() -> None:
     content = """
       
       class C {
@@ -383,7 +383,7 @@ def test_enum_private_in_class():
     )
 
 
-def test_enum_public_in_class():
+def test_enum_public_in_class() -> None:
     content = """
       
       class C {
@@ -417,7 +417,7 @@ def test_enum_public_in_class():
     )
 
 
-def test_default_enum():
+def test_default_enum() -> None:
     content = """
       class A {
         enum {
@@ -497,7 +497,7 @@ def test_default_enum():
     )
 
 
-def test_enum_template_vals():
+def test_enum_template_vals() -> None:
     content = """
       enum {
         IsRandomAccess = std::is_base_of<std::random_access_iterator_tag,
@@ -559,7 +559,7 @@ def test_enum_template_vals():
     )
 
 
-def test_enum_fn():
+def test_enum_fn() -> None:
     content = """
       enum E {
         VALUE,
diff --git a/tests/test_fn.py b/tests/test_fn.py
index c1daef0..c5688bd 100644
--- a/tests/test_fn.py
+++ b/tests/test_fn.py
@@ -31,7 +31,7 @@ from cxxheaderparser.simple import (
 )
 
 
-def test_fn_returns_class():
+def test_fn_returns_class() -> None:
     content = """
       class X *fn1();
       struct Y fn2();
@@ -77,7 +77,7 @@ def test_fn_returns_class():
     )
 
 
-def test_fn_returns_typename():
+def test_fn_returns_typename() -> None:
     content = """
       typename ns::X fn();
     """
@@ -104,7 +104,7 @@ def test_fn_returns_typename():
     )
 
 
-def test_fn_returns_typename_const():
+def test_fn_returns_typename_const() -> None:
     content = """
       const typename ns::X fn();
     """
@@ -132,7 +132,7 @@ def test_fn_returns_typename_const():
     )
 
 
-def test_fn_pointer_params():
+def test_fn_pointer_params() -> None:
     content = """
       int fn1(int *);
       int fn2(int *p);
@@ -201,7 +201,7 @@ def test_fn_pointer_params():
     )
 
 
-def test_fn_void_is_no_params():
+def test_fn_void_is_no_params() -> None:
     content = """
       int fn(void);
     """
@@ -222,7 +222,7 @@ def test_fn_void_is_no_params():
     )
 
 
-def test_fn_array_param():
+def test_fn_array_param() -> None:
     content = """
       void fn(int array[]);
     """
@@ -255,7 +255,7 @@ def test_fn_array_param():
     )
 
 
-def test_fn_typename_param():
+def test_fn_typename_param() -> None:
     content = """
       void MethodA(const mynamespace::SomeObject &x,
                    typename mynamespace::SomeObject * = 0);
@@ -307,7 +307,7 @@ def test_fn_typename_param():
     )
 
 
-def test_fn_weird_refs():
+def test_fn_weird_refs() -> None:
     content = """
       int aref(int(&x));
       void ptr_ref(int(*&name));
@@ -382,7 +382,7 @@ def test_fn_weird_refs():
     )
 
 
-def test_fn_too_many_parens():
+def test_fn_too_many_parens() -> None:
     content = """
       int fn1(int (x));
       void (fn2 (int (*const (name))));
@@ -439,7 +439,7 @@ void (__stdcall * fn)
 """
 
 
-def test_fn_same_line():
+def test_fn_same_line() -> None:
     # multiple functions on the same line
     content = """
       void fn1(), fn2();
@@ -487,7 +487,7 @@ def test_fn_same_line():
     )
 
 
-def test_fn_auto_template():
+def test_fn_auto_template() -> None:
     content = """
       template<class T, class U>
       auto add(T t, U u) { return t + u; }
@@ -527,7 +527,7 @@ def test_fn_auto_template():
     )
 
 
-def test_fn_template_ptr():
+def test_fn_template_ptr() -> None:
     content = """
       std::vector<Pointer *> *fn(std::vector<Pointer *> *ps);
     """
@@ -607,7 +607,7 @@ def test_fn_template_ptr():
     )
 
 
-def test_fn_with_impl():
+def test_fn_with_impl() -> None:
     content = """
       // clang-format off
       void termite(void)
@@ -634,7 +634,7 @@ def test_fn_with_impl():
     )
 
 
-def test_fn_return_std_function():
+def test_fn_return_std_function() -> None:
     content = """
       std::function<void(int)> fn();
     """
@@ -700,7 +700,7 @@ def test_fn_return_std_function():
     assert data2 == expected
 
 
-def test_fn_return_std_function_trailing():
+def test_fn_return_std_function_trailing() -> None:
     content = """
       std::function<auto(int)->int> fn();
     """
@@ -759,7 +759,7 @@ def test_fn_return_std_function_trailing():
     )
 
 
-def test_fn_trailing_return_simple():
+def test_fn_trailing_return_simple() -> None:
     content = """
       auto fn() -> int;
     """
@@ -781,7 +781,7 @@ def test_fn_trailing_return_simple():
     )
 
 
-def test_fn_trailing_return_std_function():
+def test_fn_trailing_return_std_function() -> None:
     content = """
       auto fn() -> std::function<int()>;
     """
@@ -828,7 +828,7 @@ def test_fn_trailing_return_std_function():
     )
 
 
-def test_inline_volatile_fn():
+def test_inline_volatile_fn() -> None:
     content = """
       inline int Standard_Atomic_Increment (volatile int* theValue);
     """
@@ -864,7 +864,7 @@ def test_inline_volatile_fn():
     )
 
 
-def test_method_w_reference():
+def test_method_w_reference() -> None:
     content = """
       struct StreamBuffer
       {
@@ -947,7 +947,7 @@ def test_method_w_reference():
     )
 
 
-def test_fn_w_mvreference():
+def test_fn_w_mvreference() -> None:
     content = """
       void fn1(int && (*)(int));
       
@@ -996,7 +996,7 @@ def test_fn_w_mvreference():
     )
 
 
-def test_msvc_conventions():
+def test_msvc_conventions() -> None:
     content = """
       void __cdecl fn();
       typedef const char* (__stdcall *wglGetExtensionsStringARB_t)(HDC theDeviceContext);
diff --git a/tests/test_friends.py b/tests/test_friends.py
index c600e1b..8355c33 100644
--- a/tests/test_friends.py
+++ b/tests/test_friends.py
@@ -23,7 +23,7 @@ from cxxheaderparser.simple import (
 )
 
 # friends
-def test_various_friends():
+def test_various_friends() -> None:
     content = """
       class FX {
       public:
@@ -170,7 +170,7 @@ def test_various_friends():
     )
 
 
-def test_more_friends():
+def test_more_friends() -> None:
     content = """
       template <typename T> struct X { static int x; };
       
@@ -285,7 +285,7 @@ def test_more_friends():
     )
 
 
-def test_friend_type_no_class():
+def test_friend_type_no_class() -> None:
     content = """
       class DogClass;
       class CatClass {
@@ -327,7 +327,7 @@ def test_friend_type_no_class():
     )
 
 
-def test_friend_with_impl():
+def test_friend_with_impl() -> None:
     content = """
       // clang-format off
       class Garlic {
diff --git a/tests/test_misc.py b/tests/test_misc.py
index a9dd0d2..b90fd96 100644
--- a/tests/test_misc.py
+++ b/tests/test_misc.py
@@ -28,7 +28,7 @@ from cxxheaderparser.simple import (
 #
 
 
-def test_define():
+def test_define() -> None:
     content = """
         #define simple
         #define complex(thing) stuff(thing)
@@ -45,7 +45,7 @@ def test_define():
     )
 
 
-def test_includes():
+def test_includes() -> None:
     content = """
         #include <global.h>
         #include "local.h"
@@ -55,7 +55,7 @@ def test_includes():
     assert data == ParsedData(includes=[Include("<global.h>"), Include('"local.h"')])
 
 
-def test_pragma():
+def test_pragma() -> None:
     content = """
 
         #pragma once
@@ -71,7 +71,7 @@ def test_pragma():
 #
 
 
-def test_extern_c():
+def test_extern_c() -> None:
     content = """
       extern "C" {
       int x;
@@ -101,7 +101,7 @@ def test_extern_c():
     )
 
 
-def test_misc_extern_inline():
+def test_misc_extern_inline() -> None:
     content = """
       extern "C++" {
       inline HAL_Value HAL_GetSimValue(HAL_SimValueHandle handle) {
@@ -143,7 +143,7 @@ def test_misc_extern_inline():
 #
 
 
-def test_static_assert_1():
+def test_static_assert_1() -> None:
     # static_assert should be ignored
     content = """
         static_assert(x == 1);
@@ -153,7 +153,7 @@ def test_static_assert_1():
     assert data == ParsedData()
 
 
-def test_static_assert_2():
+def test_static_assert_2() -> None:
     # static_assert should be ignored
     content = """
         static_assert(sizeof(int) == 4, 
@@ -165,7 +165,7 @@ def test_static_assert_2():
     assert data == ParsedData()
 
 
-def test_comment_eof():
+def test_comment_eof() -> None:
     content = """
       namespace a {} // namespace a"""
     data = parse_string(content, cleandoc=True)
@@ -175,7 +175,7 @@ def test_comment_eof():
     )
 
 
-def test_final():
+def test_final() -> None:
     content = """
       // ok here
       int fn(const int final);
diff --git a/tests/test_namespaces.py b/tests/test_namespaces.py
index 2b99f33..74f7f57 100644
--- a/tests/test_namespaces.py
+++ b/tests/test_namespaces.py
@@ -16,7 +16,7 @@ from cxxheaderparser.simple import (
 )
 
 
-def test_dups_in_different_ns():
+def test_dups_in_different_ns() -> None:
     content = """
       
       namespace {
@@ -58,7 +58,7 @@ def test_dups_in_different_ns():
     )
 
 
-def test_correct_ns():
+def test_correct_ns() -> None:
     content = """
       namespace a::b::c {
         int i1;
diff --git a/tests/test_operators.py b/tests/test_operators.py
index ae060ce..8d3bb60 100644
--- a/tests/test_operators.py
+++ b/tests/test_operators.py
@@ -18,7 +18,7 @@ from cxxheaderparser.simple import (
 )
 
 
-def test_class_operators():
+def test_class_operators() -> None:
     content = r"""
       class OperatorClass {
       public:
@@ -554,7 +554,7 @@ def test_class_operators():
     )
 
 
-def test_conversion_operators():
+def test_conversion_operators() -> None:
     content = """
       
       class Foo
diff --git a/tests/test_template.py b/tests/test_template.py
index 85e0e72..6a9e246 100644
--- a/tests/test_template.py
+++ b/tests/test_template.py
@@ -29,7 +29,7 @@ from cxxheaderparser.types import (
 from cxxheaderparser.simple import ClassScope, NamespaceScope, ParsedData, parse_string
 
 
-def test_template_base_template_ns():
+def test_template_base_template_ns() -> None:
     content = """
       class A : public B<int, int>::C {};
     """
@@ -89,7 +89,7 @@ def test_template_base_template_ns():
     )
 
 
-def test_template_non_type_various():
+def test_template_non_type_various() -> None:
     content = """
       // simple non-type template parameter
       template <int N> struct S { int a[N]; };
@@ -257,7 +257,7 @@ def test_template_non_type_various():
     )
 
 
-def test_template_dependent_nontype_default():
+def test_template_dependent_nontype_default() -> None:
     content = """
       template <class T, typename T::type n = 0> class X;
     """
@@ -293,7 +293,7 @@ def test_template_dependent_nontype_default():
     )
 
 
-def test_template_optional_names():
+def test_template_optional_names() -> None:
     content = """
       template <class> class My_vector;
       template <class = void> struct My_op_functor;
@@ -337,7 +337,7 @@ def test_template_optional_names():
     )
 
 
-def test_template_template_template():
+def test_template_template_template() -> None:
     content = """
       template<typename T> struct eval; // primary template 
  
@@ -438,7 +438,7 @@ def test_template_template_template():
     )
 
 
-def test_template_static_var():
+def test_template_static_var() -> None:
     content = """
       template <typename T>
       struct X {
@@ -510,7 +510,7 @@ def test_template_static_var():
     )
 
 
-def test_template_fn_template():
+def test_template_fn_template() -> None:
     content = """
       class S {
         template <typename Allocator> StringRef copy(Allocator &A) const {
@@ -574,7 +574,7 @@ def test_template_fn_template():
     )
 
 
-def test_template_fn_param_initializer():
+def test_template_fn_param_initializer() -> None:
     content = """
       template <typename T, typename U>
       void fn(something<T, U> s = something<T, U>{1, 2, 3});
@@ -658,7 +658,7 @@ def test_template_fn_param_initializer():
     )
 
 
-def test_template_huge():
+def test_template_huge() -> None:
     content = """
       // clang-format off
       class AlmondClass
@@ -872,7 +872,7 @@ def test_template_huge():
     )
 
 
-def test_template_specialized():
+def test_template_specialized() -> None:
     content = """
       template <> class FruitFly<int> : public Fly {};
     """
@@ -920,7 +920,7 @@ def test_template_specialized():
     )
 
 
-def test_template_class_defaults():
+def test_template_class_defaults() -> None:
     content = """
       template <typename VALUE, typename VALUE_SET_ITERATOR,
                 typename ACCESSOR = Raddish::SimpleAccessor<VALUE, VALUE_SET_ITERATOR>>
@@ -1068,7 +1068,7 @@ def test_template_class_defaults():
     )
 
 
-def test_template_many_packs():
+def test_template_many_packs() -> None:
     content = """
       // clang-format off
       
@@ -1651,7 +1651,7 @@ def test_template_many_packs():
     )
 
 
-def test_template_specialized_fn_typename():
+def test_template_specialized_fn_typename() -> None:
     content = """
       // clang-format off
       struct T{};
@@ -1723,7 +1723,7 @@ def test_template_specialized_fn_typename():
     )
 
 
-def test_template_specialized_fn_typename_template():
+def test_template_specialized_fn_typename_template() -> None:
     content = """
       // clang-format off
       template <typename X>
diff --git a/tests/test_tokfmt.py b/tests/test_tokfmt.py
index cff0f1a..ba245c3 100644
--- a/tests/test_tokfmt.py
+++ b/tests/test_tokfmt.py
@@ -2,6 +2,7 @@ import pytest
 
 from cxxheaderparser.lexer import Lexer
 from cxxheaderparser.tokfmt import tokfmt
+from cxxheaderparser.types import Token
 
 
 @pytest.mark.parametrize(
@@ -34,7 +35,7 @@ from cxxheaderparser.tokfmt import tokfmt
         "operator>=",
     ],
 )
-def test_tokfmt(instr):
+def test_tokfmt(instr: str) -> None:
     """
     Each input string is exactly what the output of tokfmt should be
     """
@@ -47,6 +48,6 @@ def test_tokfmt(instr):
         if not tok:
             break
 
-        toks.append(tok)
+        toks.append(Token(tok.value, tok.type))
 
     assert tokfmt(toks) == instr
diff --git a/tests/test_typedef.py b/tests/test_typedef.py
index a1819e3..71bd0c5 100644
--- a/tests/test_typedef.py
+++ b/tests/test_typedef.py
@@ -26,7 +26,7 @@ from cxxheaderparser.types import (
 from cxxheaderparser.simple import ClassScope, NamespaceScope, ParsedData, parse_string
 
 
-def test_simple_typedef():
+def test_simple_typedef() -> None:
     content = """
       typedef std::vector<int> IntVector;
     """
@@ -68,7 +68,7 @@ def test_simple_typedef():
     )
 
 
-def test_struct_typedef_1():
+def test_struct_typedef_1() -> None:
     content = """
       typedef struct {
         int m;
@@ -122,7 +122,7 @@ def test_struct_typedef_1():
     )
 
 
-def test_struct_typedef_2():
+def test_struct_typedef_2() -> None:
     content = """
       typedef struct {
         int m;
@@ -176,7 +176,7 @@ def test_struct_typedef_2():
     )
 
 
-def test_typedef_array():
+def test_typedef_array() -> None:
     content = """
       typedef char TenCharArray[10];
     """
@@ -201,7 +201,7 @@ def test_typedef_array():
     )
 
 
-def test_typedef_array_of_struct():
+def test_typedef_array_of_struct() -> None:
     content = """
       typedef struct{} tx[3], ty;
     """
@@ -243,7 +243,7 @@ def test_typedef_array_of_struct():
     )
 
 
-def test_typedef_class_w_base():
+def test_typedef_class_w_base() -> None:
     content = """
       typedef class XX : public F {} G;
     """
@@ -280,7 +280,7 @@ def test_typedef_class_w_base():
     )
 
 
-def test_complicated_typedef():
+def test_complicated_typedef() -> None:
     content = """
       typedef int int_t, *intp_t, (&fp)(int, ulong), arr_t[10];
     """
@@ -345,7 +345,7 @@ def test_complicated_typedef():
     )
 
 
-def test_typedef_c_struct_idiom():
+def test_typedef_c_struct_idiom() -> None:
     content = """
       // common C idiom to avoid having to write "struct S"
       typedef struct {int a; int b;} S, *pS;
@@ -407,7 +407,7 @@ def test_typedef_c_struct_idiom():
     )
 
 
-def test_typedef_struct_same_name():
+def test_typedef_struct_same_name() -> None:
     content = """
       typedef struct Fig {
         int a;
@@ -451,7 +451,7 @@ def test_typedef_struct_same_name():
     )
 
 
-def test_typedef_struct_w_enum():
+def test_typedef_struct_w_enum() -> None:
     content = """
       typedef struct {
         enum BeetEnum : int { FAIL = 0, PASS = 1 };
@@ -502,7 +502,7 @@ def test_typedef_struct_w_enum():
     )
 
 
-def test_typedef_union():
+def test_typedef_union() -> None:
     content = """
       typedef union apricot_t {
         int i;
@@ -569,7 +569,7 @@ def test_typedef_union():
     )
 
 
-def test_typedef_fnptr():
+def test_typedef_fnptr() -> None:
     content = """
       typedef void *(*fndef)(int);
     """
@@ -606,7 +606,7 @@ def test_typedef_fnptr():
     )
 
 
-def test_typedef_const():
+def test_typedef_const() -> None:
     content = """
       typedef int theint, *const ptheint;
     """
@@ -635,7 +635,7 @@ def test_typedef_const():
     )
 
 
-def test_enum_typedef_1():
+def test_enum_typedef_1() -> None:
     content = """
       typedef enum {} E;
     """
@@ -661,7 +661,7 @@ def test_enum_typedef_1():
     )
 
 
-def test_enum_typedef_2():
+def test_enum_typedef_2() -> None:
     content = """
       typedef enum { E1 } BE;
     """
@@ -687,7 +687,7 @@ def test_enum_typedef_2():
     )
 
 
-def test_enum_typedef_3():
+def test_enum_typedef_3() -> None:
     content = """
       typedef enum { E1, E2, } E;
     """
@@ -713,7 +713,7 @@ def test_enum_typedef_3():
     )
 
 
-def test_enum_typedef_3_1():
+def test_enum_typedef_3_1() -> None:
     content = """
       typedef enum { E1 } * PBE;
     """
@@ -743,7 +743,7 @@ def test_enum_typedef_3_1():
     )
 
 
-def test_enum_typedef_4():
+def test_enum_typedef_4() -> None:
     content = """
       typedef enum { E1 } * PBE, BE;
     """
@@ -779,7 +779,7 @@ def test_enum_typedef_4():
     )
 
 
-def test_enum_typedef_5():
+def test_enum_typedef_5() -> None:
     content = """
       typedef enum { E1 } BE, *PBE;
     """
@@ -815,7 +815,7 @@ def test_enum_typedef_5():
     )
 
 
-def test_enum_typedef_fwd():
+def test_enum_typedef_fwd() -> None:
     content = """
       typedef enum BE BET;
     """
@@ -837,7 +837,7 @@ def test_enum_typedef_fwd():
     )
 
 
-def test_typedef_enum_expr():
+def test_typedef_enum_expr() -> None:
     content = """
       typedef enum { StarFruit = (2 + 2) / 2 } Carambola;
     """
@@ -878,7 +878,7 @@ def test_typedef_enum_expr():
     )
 
 
-def test_volatile_typedef():
+def test_volatile_typedef() -> None:
     content = """
       typedef volatile signed short vint16;
     """
@@ -901,7 +901,7 @@ def test_volatile_typedef():
     )
 
 
-def test_function_typedef():
+def test_function_typedef() -> None:
     content = """
       typedef void fn(int);
       typedef auto fntype(int) -> int;
diff --git a/tests/test_union.py b/tests/test_union.py
index d9a660f..ffbb9c9 100644
--- a/tests/test_union.py
+++ b/tests/test_union.py
@@ -17,7 +17,7 @@ from cxxheaderparser.simple import (
 )
 
 
-def test_union_basic():
+def test_union_basic() -> None:
     content = """
       
       struct HAL_Value {
@@ -86,7 +86,7 @@ def test_union_basic():
     )
 
 
-def test_union_anon_in_struct():
+def test_union_anon_in_struct() -> None:
     content = """
       struct Outer {
         union {
diff --git a/tests/test_using.py b/tests/test_using.py
index 616257a..ca1d76e 100644
--- a/tests/test_using.py
+++ b/tests/test_using.py
@@ -30,7 +30,7 @@ from cxxheaderparser.simple import (
 )
 
 
-def test_using_namespace():
+def test_using_namespace() -> None:
     content = """
       using namespace foo;
       using namespace foo::bar;
@@ -52,7 +52,7 @@ def test_using_namespace():
     )
 
 
-def test_using_declaration():
+def test_using_declaration() -> None:
     content = """
       using ::foo;
       using foo::bar;
@@ -104,7 +104,7 @@ def test_using_declaration():
 
 
 # alias-declaration
-def test_alias_declaration_1():
+def test_alias_declaration_1() -> None:
     content = """
       using alias = foo;
     """
@@ -122,7 +122,7 @@ def test_alias_declaration_1():
     )
 
 
-def test_alias_declaration_2():
+def test_alias_declaration_2() -> None:
     content = """
       template <typename T> using alias = foo<T>;
     """
@@ -164,7 +164,7 @@ def test_alias_declaration_2():
     )
 
 
-def test_alias_declaration_3():
+def test_alias_declaration_3() -> None:
     content = """
       using alias = ::foo::bar;
     """
@@ -190,7 +190,7 @@ def test_alias_declaration_3():
     )
 
 
-def test_alias_declaration_4():
+def test_alias_declaration_4() -> None:
     content = """
       template <typename T> using alias = ::foo::bar<T>;
     """
@@ -234,7 +234,7 @@ def test_alias_declaration_4():
     )
 
 
-def test_alias_declaration_5():
+def test_alias_declaration_5() -> None:
     content = """
       using alias = foo::bar;
     """
@@ -259,7 +259,7 @@ def test_alias_declaration_5():
     )
 
 
-def test_alias_declaration_6():
+def test_alias_declaration_6() -> None:
     content = """
       template <typename T> using alias = foo<T>::bar;
     """
@@ -302,7 +302,7 @@ def test_alias_declaration_6():
     )
 
 
-def test_using_many_things():
+def test_using_many_things() -> None:
     content = """
       // clang-format off
       
diff --git a/tests/test_var.py b/tests/test_var.py
index 3621959..488ad10 100644
--- a/tests/test_var.py
+++ b/tests/test_var.py
@@ -22,7 +22,7 @@ from cxxheaderparser.types import (
 from cxxheaderparser.simple import ClassScope, NamespaceScope, ParsedData, parse_string
 
 
-def test_var_unixwiz_ridiculous():
+def test_var_unixwiz_ridiculous() -> None:
     # http://unixwiz.net/techtips/reading-cdecl.html
     #
     # .. "we have no idea how this variable is useful, but at least we can
@@ -73,7 +73,7 @@ def test_var_unixwiz_ridiculous():
     )
 
 
-def test_var_ptr_to_array15_of_ptr_to_int():
+def test_var_ptr_to_array15_of_ptr_to_int() -> None:
     content = """
       int *(*crocodile)[15];
     """
@@ -102,7 +102,7 @@ def test_var_ptr_to_array15_of_ptr_to_int():
     )
 
 
-def test_var_ref_to_array():
+def test_var_ref_to_array() -> None:
     content = """
       int abase[3];
       int (&aname)[3] = abase;
@@ -140,7 +140,7 @@ def test_var_ref_to_array():
     )
 
 
-def test_var_ptr_to_array():
+def test_var_ptr_to_array() -> None:
     content = """
       int zz, (*aname)[3] = &abase;
     """
@@ -174,7 +174,7 @@ def test_var_ptr_to_array():
     )
 
 
-def test_var_multi_1():
+def test_var_multi_1() -> None:
     content = """
       int zz, (&aname)[3] = abase;
     """
@@ -208,7 +208,7 @@ def test_var_multi_1():
     )
 
 
-def test_var_array_of_fnptr_varargs():
+def test_var_array_of_fnptr_varargs() -> None:
     content = """
       void (*a3[3])(int, ...);
     """
@@ -249,7 +249,7 @@ def test_var_array_of_fnptr_varargs():
     )
 
 
-def test_var_double_fnptr_varargs():
+def test_var_double_fnptr_varargs() -> None:
     content = """
       void (*(*a4))(int, ...);
     """
@@ -289,7 +289,7 @@ def test_var_double_fnptr_varargs():
     )
 
 
-def test_var_fnptr_voidstar():
+def test_var_fnptr_voidstar() -> None:
     content = """
       void(*(*a5)(int));
     """
@@ -326,7 +326,7 @@ def test_var_fnptr_voidstar():
     )
 
 
-def test_var_fnptr_moreparens():
+def test_var_fnptr_moreparens() -> None:
     content = """
       void (*x)(int(p1), int);
     """
@@ -384,7 +384,7 @@ def test_var_fnptr_moreparens():
 # Means "const pointer to pointer to char"
 
 
-def test_var_ptr_to_const_ptr_to_char():
+def test_var_ptr_to_const_ptr_to_char() -> None:
     content = """
       char *const *p;
     """
@@ -411,7 +411,7 @@ def test_var_ptr_to_const_ptr_to_char():
     )
 
 
-def test_var_const_ptr_to_ptr_to_char():
+def test_var_const_ptr_to_ptr_to_char() -> None:
     content = """
       char **const p;
     """
@@ -438,7 +438,7 @@ def test_var_const_ptr_to_ptr_to_char():
     )
 
 
-def test_var_array_initializer1():
+def test_var_array_initializer1() -> None:
     content = """
       int x[3]{1, 2, 3};
     """
@@ -472,7 +472,7 @@ def test_var_array_initializer1():
     )
 
 
-def test_var_array_initializer2():
+def test_var_array_initializer2() -> None:
     content = """
       int x[3] = {1, 2, 3};
     """
@@ -506,7 +506,7 @@ def test_var_array_initializer2():
     )
 
 
-def test_var_extern_c():
+def test_var_extern_c() -> None:
     content = """
       extern "C" int x;
     """
@@ -528,7 +528,7 @@ def test_var_extern_c():
     )
 
 
-def test_var_ns_1():
+def test_var_ns_1() -> None:
     content = """
       int N::x;
     """
@@ -550,7 +550,7 @@ def test_var_ns_1():
     )
 
 
-def test_var_ns_2():
+def test_var_ns_2() -> None:
     content = """
       int N::x = 4;
     """
@@ -573,7 +573,7 @@ def test_var_ns_2():
     )
 
 
-def test_var_ns_3():
+def test_var_ns_3() -> None:
     content = """
       int N::x{4};
     """
@@ -598,7 +598,7 @@ def test_var_ns_3():
     )
 
 
-def test_var_static_struct():
+def test_var_static_struct() -> None:
     content = """
       constexpr static struct SS {} s;
     """
@@ -631,7 +631,7 @@ def test_var_static_struct():
     )
 
 
-def test_var_constexpr_enum():
+def test_var_constexpr_enum() -> None:
     content = """
       constexpr enum E { EE } e = EE;
     """
@@ -663,7 +663,7 @@ def test_var_constexpr_enum():
     )
 
 
-def test_var_fnptr_in_class():
+def test_var_fnptr_in_class() -> None:
     content = """
       struct DriverFuncs {
         void *(*init)();
@@ -747,7 +747,7 @@ def test_var_fnptr_in_class():
     )
 
 
-def test_var_extern():
+def test_var_extern() -> None:
     content = """
       extern int externVar;
     """