diff --git a/src/graphql/execution/middleware.py b/src/graphql/execution/middleware.py
index ebbbde00..334a088a 100644
--- a/src/graphql/execution/middleware.py
+++ b/src/graphql/execution/middleware.py
@@ -25,7 +25,7 @@ class MiddlewareManager:
     _cached_resolvers: Dict[GraphQLFieldResolver, GraphQLFieldResolver]
     _middleware_resolvers: Optional[List[Callable]]
 
-    def __init__(self, *middlewares: Any) -> None:
+    def __init__(self, *middlewares: Any):
         self.middlewares = middlewares
         self._middleware_resolvers = (
             list(get_middleware_resolvers(middlewares)) if middlewares else None
diff --git a/src/graphql/language/lexer.py b/src/graphql/language/lexer.py
index bad4196d..40e3bbc6 100644
--- a/src/graphql/language/lexer.py
+++ b/src/graphql/language/lexer.py
@@ -67,7 +67,7 @@ class Lexer:
     EOF token whenever called.
     """
 
-    def __init__(self, source: Source) -> None:
+    def __init__(self, source: Source):
         """Given a Source object, initialize a Lexer for that source."""
         self.source = source
         self.token = self.last_token = Token(TokenKind.SOF, 0, 0, 0, 0)
diff --git a/src/graphql/language/visitor.py b/src/graphql/language/visitor.py
index b128e3aa..95d41a13 100644
--- a/src/graphql/language/visitor.py
+++ b/src/graphql/language/visitor.py
@@ -341,7 +341,7 @@ class ParallelVisitor(Visitor):
     If a prior visitor edits a node, no following visitors will see that node.
     """
 
-    def __init__(self, visitors: Collection[Visitor]) -> None:
+    def __init__(self, visitors: Collection[Visitor]):
         """Create a new visitor from the given list of parallel visitors."""
         self.visitors = visitors
         self.skipping: List[Any] = [None] * len(visitors)
diff --git a/src/graphql/pyutils/event_emitter.py b/src/graphql/pyutils/event_emitter.py
index 4d0a07b0..08b05b82 100644
--- a/src/graphql/pyutils/event_emitter.py
+++ b/src/graphql/pyutils/event_emitter.py
@@ -11,7 +11,7 @@
 class EventEmitter:
     """A very simple EventEmitter."""
 
-    def __init__(self, loop: Optional[AbstractEventLoop] = None) -> None:
+    def __init__(self, loop: Optional[AbstractEventLoop] = None):
         self.loop = loop
         self.listeners: Dict[str, List[Callable]] = defaultdict(list)
 
@@ -43,7 +43,7 @@ class EventEmitterAsyncIterator:
     Useful for mocking a PubSub system for tests.
     """
 
-    def __init__(self, event_emitter: EventEmitter, event_name: str) -> None:
+    def __init__(self, event_emitter: EventEmitter, event_name: str):
         self.queue: Queue = Queue(loop=cast(AbstractEventLoop, event_emitter.loop))
         event_emitter.add_listener(event_name, self.queue.put)
         self.remove_listener = lambda: event_emitter.remove_listener(
diff --git a/src/graphql/type/definition.py b/src/graphql/type/definition.py
index bde649fc..e9e96086 100644
--- a/src/graphql/type/definition.py
+++ b/src/graphql/type/definition.py
@@ -161,7 +161,7 @@ class GraphQLWrappingType(GraphQLType, Generic[GT]):
 
     of_type: GT
 
-    def __init__(self, type_: GT) -> None:
+    def __init__(self, type_: GT):
         if not is_type(type_):
             raise TypeError(
                 f"Can only create a wrapper for a GraphQLType, but got: {type_}."
@@ -1415,7 +1415,7 @@ def fields(self):
                 }
     """
 
-    def __init__(self, type_: GT) -> None:
+    def __init__(self, type_: GT):
         super().__init__(type_=type_)
 
     def __str__(self):
@@ -1455,7 +1455,7 @@ class RowType(GraphQLObjectType):
     Note: the enforcement of non-nullability occurs within the executor.
     """
 
-    def __init__(self, type_: GNT) -> None:
+    def __init__(self, type_: GNT):
         super().__init__(type_=type_)
         if isinstance(type_, GraphQLNonNull):
             raise TypeError(
diff --git a/src/graphql/type/validate.py b/src/graphql/type/validate.py
index b4b4176e..e833be50 100644
--- a/src/graphql/type/validate.py
+++ b/src/graphql/type/validate.py
@@ -90,7 +90,7 @@ class SchemaValidationContext:
     errors: List[GraphQLError]
     schema: GraphQLSchema
 
-    def __init__(self, schema: GraphQLSchema) -> None:
+    def __init__(self, schema: GraphQLSchema):
         self.errors = []
         self.schema = schema
 
@@ -500,7 +500,7 @@ def get_operation_type_node(
 class InputObjectCircularRefsValidator:
     """Modified copy of algorithm from validation.rules.NoFragmentCycles"""
 
-    def __init__(self, context: SchemaValidationContext) -> None:
+    def __init__(self, context: SchemaValidationContext):
         self.context = context
         # Tracks already visited types to maintain O(N) and to ensure that cycles
         # are not redundantly reported.
diff --git a/src/graphql/utilities/find_deprecated_usages.py b/src/graphql/utilities/find_deprecated_usages.py
index 5cfc903e..429cc407 100644
--- a/src/graphql/utilities/find_deprecated_usages.py
+++ b/src/graphql/utilities/find_deprecated_usages.py
@@ -26,7 +26,7 @@ class FindDeprecatedUsages(Visitor):
     type_info: TypeInfo
     errors: List[GraphQLError]
 
-    def __init__(self, type_info: TypeInfo) -> None:
+    def __init__(self, type_info: TypeInfo):
         super().__init__()
         self.type_info = type_info
         self.errors = []
diff --git a/src/graphql/utilities/type_info.py b/src/graphql/utilities/type_info.py
index e86fe0df..5be0869b 100644
--- a/src/graphql/utilities/type_info.py
+++ b/src/graphql/utilities/type_info.py
@@ -288,7 +288,7 @@ def get_field_def(
 class TypeInfoVisitor(Visitor):
     """A visitor which maintains a provided TypeInfo."""
 
-    def __init__(self, type_info: "TypeInfo", visitor: Visitor) -> None:
+    def __init__(self, type_info: "TypeInfo", visitor: Visitor):
         self.type_info = type_info
         self.visitor = visitor
 
diff --git a/src/graphql/validation/rules/__init__.py b/src/graphql/validation/rules/__init__.py
index ade50427..24ebfb52 100644
--- a/src/graphql/validation/rules/__init__.py
+++ b/src/graphql/validation/rules/__init__.py
@@ -18,7 +18,7 @@ class ASTValidationRule(Visitor):
 
     context: ASTValidationContext
 
-    def __init__(self, context: ASTValidationContext) -> None:
+    def __init__(self, context: ASTValidationContext):
         self.context = context
 
     def report_error(self, error: GraphQLError):
@@ -30,7 +30,7 @@ class SDLValidationRule(ASTValidationRule):
 
     context: ValidationContext
 
-    def __init__(self, context: SDLValidationContext) -> None:
+    def __init__(self, context: SDLValidationContext):
         super().__init__(context)
 
 
@@ -39,7 +39,7 @@ class ValidationRule(ASTValidationRule):
 
     context: ValidationContext
 
-    def __init__(self, context: ValidationContext) -> None:
+    def __init__(self, context: ValidationContext):
         super().__init__(context)
 
 
diff --git a/src/graphql/validation/rules/known_argument_names.py b/src/graphql/validation/rules/known_argument_names.py
index fd446689..f89f9fb7 100644
--- a/src/graphql/validation/rules/known_argument_names.py
+++ b/src/graphql/validation/rules/known_argument_names.py
@@ -19,7 +19,7 @@ class KnownArgumentNamesOnDirectivesRule(ASTValidationRule):
 
     context: Union[ValidationContext, SDLValidationContext]
 
-    def __init__(self, context: Union[ValidationContext, SDLValidationContext]) -> None:
+    def __init__(self, context: Union[ValidationContext, SDLValidationContext]):
         super().__init__(context)
         directive_args: Dict[str, List[str]] = {}
 
@@ -64,7 +64,7 @@ class KnownArgumentNamesRule(KnownArgumentNamesOnDirectivesRule):
 
     context: ValidationContext
 
-    def __init__(self, context: ValidationContext) -> None:
+    def __init__(self, context: ValidationContext):
         super().__init__(context)
 
     def enter_argument(self, arg_node: ArgumentNode, *args):
diff --git a/src/graphql/validation/rules/known_directives.py b/src/graphql/validation/rules/known_directives.py
index 63642ed5..c23f00d1 100644
--- a/src/graphql/validation/rules/known_directives.py
+++ b/src/graphql/validation/rules/known_directives.py
@@ -23,7 +23,7 @@ class KnownDirectivesRule(ASTValidationRule):
 
     context: Union[ValidationContext, SDLValidationContext]
 
-    def __init__(self, context: Union[ValidationContext, SDLValidationContext]) -> None:
+    def __init__(self, context: Union[ValidationContext, SDLValidationContext]):
         super().__init__(context)
         locations_map: Dict[str, List[DirectiveLocation]] = {}
 
diff --git a/src/graphql/validation/rules/known_type_names.py b/src/graphql/validation/rules/known_type_names.py
index 29bd65a8..ae93712e 100644
--- a/src/graphql/validation/rules/known_type_names.py
+++ b/src/graphql/validation/rules/known_type_names.py
@@ -23,7 +23,7 @@ class KnownTypeNamesRule(ASTValidationRule):
     definitions and fragment conditions) are defined by the type schema.
     """
 
-    def __init__(self, context: Union[ValidationContext, SDLValidationContext]) -> None:
+    def __init__(self, context: Union[ValidationContext, SDLValidationContext]):
         super().__init__(context)
         schema = context.schema
         self.existing_types_map = schema.type_map if schema else {}
diff --git a/src/graphql/validation/rules/lone_anonymous_operation.py b/src/graphql/validation/rules/lone_anonymous_operation.py
index 487564aa..426ccac2 100644
--- a/src/graphql/validation/rules/lone_anonymous_operation.py
+++ b/src/graphql/validation/rules/lone_anonymous_operation.py
@@ -12,7 +12,7 @@ class LoneAnonymousOperationRule(ASTValidationRule):
     (the query short-hand) that it contains only that one operation definition.
     """
 
-    def __init__(self, context: ASTValidationContext) -> None:
+    def __init__(self, context: ASTValidationContext):
         super().__init__(context)
         self.operation_count = 0
 
diff --git a/src/graphql/validation/rules/lone_schema_definition.py b/src/graphql/validation/rules/lone_schema_definition.py
index d2ad1034..fd242914 100644
--- a/src/graphql/validation/rules/lone_schema_definition.py
+++ b/src/graphql/validation/rules/lone_schema_definition.py
@@ -11,7 +11,7 @@ class LoneSchemaDefinitionRule(SDLValidationRule):
     A GraphQL document is only valid if it contains only one schema definition.
     """
 
-    def __init__(self, context: SDLValidationContext) -> None:
+    def __init__(self, context: SDLValidationContext):
         super().__init__(context)
         old_schema = context.schema
         self.already_defined = old_schema and (
diff --git a/src/graphql/validation/rules/no_fragment_cycles.py b/src/graphql/validation/rules/no_fragment_cycles.py
index 0788ed7a..5b4d63bf 100644
--- a/src/graphql/validation/rules/no_fragment_cycles.py
+++ b/src/graphql/validation/rules/no_fragment_cycles.py
@@ -10,7 +10,7 @@
 class NoFragmentCyclesRule(ASTValidationRule):
     """No fragment cycles"""
 
-    def __init__(self, context: ASTValidationContext) -> None:
+    def __init__(self, context: ASTValidationContext):
         super().__init__(context)
         # Tracks already visited fragments to maintain O(N) and to ensure that
         # cycles are not redundantly reported.
diff --git a/src/graphql/validation/rules/no_undefined_variables.py b/src/graphql/validation/rules/no_undefined_variables.py
index e6bfdf88..9a5bc852 100644
--- a/src/graphql/validation/rules/no_undefined_variables.py
+++ b/src/graphql/validation/rules/no_undefined_variables.py
@@ -14,7 +14,7 @@ class NoUndefinedVariablesRule(ValidationRule):
     via fragment spreads, are defined by that operation.
     """
 
-    def __init__(self, context: ValidationContext) -> None:
+    def __init__(self, context: ValidationContext):
         super().__init__(context)
         self.defined_variable_names: Set[str] = set()
 
diff --git a/src/graphql/validation/rules/no_unused_fragments.py b/src/graphql/validation/rules/no_unused_fragments.py
index dc2b75ba..710e1399 100644
--- a/src/graphql/validation/rules/no_unused_fragments.py
+++ b/src/graphql/validation/rules/no_unused_fragments.py
@@ -14,7 +14,7 @@ class NoUnusedFragmentsRule(ASTValidationRule):
     operations, or spread within other fragments spread within operations.
     """
 
-    def __init__(self, context: ASTValidationContext) -> None:
+    def __init__(self, context: ASTValidationContext):
         super().__init__(context)
         self.operation_defs: List[OperationDefinitionNode] = []
         self.fragment_defs: List[FragmentDefinitionNode] = []
diff --git a/src/graphql/validation/rules/no_unused_variables.py b/src/graphql/validation/rules/no_unused_variables.py
index 22a23f01..eb655372 100644
--- a/src/graphql/validation/rules/no_unused_variables.py
+++ b/src/graphql/validation/rules/no_unused_variables.py
@@ -14,7 +14,7 @@ class NoUnusedVariablesRule(ValidationRule):
     either directly or within a spread fragment.
     """
 
-    def __init__(self, context: ValidationContext) -> None:
+    def __init__(self, context: ValidationContext):
         super().__init__(context)
         self.variable_defs: List[VariableDefinitionNode] = []
 
diff --git a/src/graphql/validation/rules/overlapping_fields_can_be_merged.py b/src/graphql/validation/rules/overlapping_fields_can_be_merged.py
index 28325a8f..3ee7775a 100644
--- a/src/graphql/validation/rules/overlapping_fields_can_be_merged.py
+++ b/src/graphql/validation/rules/overlapping_fields_can_be_merged.py
@@ -50,7 +50,7 @@ class OverlappingFieldsCanBeMergedRule(ValidationRule):
     either correspond to distinct response names or can be merged without ambiguity.
     """
 
-    def __init__(self, context: ValidationContext) -> None:
+    def __init__(self, context: ValidationContext):
         super().__init__(context)
         # A memoization for when two fragments are compared "between" each other for
         # conflicts. Two fragments may be compared many times, so memoizing this can
diff --git a/src/graphql/validation/rules/possible_type_extensions.py b/src/graphql/validation/rules/possible_type_extensions.py
index 718ad056..2f28afb8 100644
--- a/src/graphql/validation/rules/possible_type_extensions.py
+++ b/src/graphql/validation/rules/possible_type_extensions.py
@@ -24,7 +24,7 @@ class PossibleTypeExtensionsRule(SDLValidationRule):
      A type extension is only valid if the type is defined and has the same kind.
     """
 
-    def __init__(self, context: SDLValidationContext) -> None:
+    def __init__(self, context: SDLValidationContext):
         super().__init__(context)
         self.schema = context.schema
         self.defined_types = {
diff --git a/src/graphql/validation/rules/provided_required_arguments.py b/src/graphql/validation/rules/provided_required_arguments.py
index 32f262d2..bd110181 100644
--- a/src/graphql/validation/rules/provided_required_arguments.py
+++ b/src/graphql/validation/rules/provided_required_arguments.py
@@ -28,7 +28,7 @@ class ProvidedRequiredArgumentsOnDirectivesRule(ASTValidationRule):
 
     context: Union[ValidationContext, SDLValidationContext]
 
-    def __init__(self, context: Union[ValidationContext, SDLValidationContext]) -> None:
+    def __init__(self, context: Union[ValidationContext, SDLValidationContext]):
         super().__init__(context)
         required_args_map: Dict[
             str, Dict[str, Union[GraphQLArgument, InputValueDefinitionNode]]
@@ -92,7 +92,7 @@ class ProvidedRequiredArgumentsRule(ProvidedRequiredArgumentsOnDirectivesRule):
 
     context: ValidationContext
 
-    def __init__(self, context: ValidationContext) -> None:
+    def __init__(self, context: ValidationContext):
         super().__init__(context)
 
     def leave_field(self, field_node: FieldNode, *_args):
diff --git a/src/graphql/validation/rules/unique_argument_names.py b/src/graphql/validation/rules/unique_argument_names.py
index 057ed7ed..77f406e1 100644
--- a/src/graphql/validation/rules/unique_argument_names.py
+++ b/src/graphql/validation/rules/unique_argument_names.py
@@ -14,7 +14,7 @@ class UniqueArgumentNamesRule(ASTValidationRule):
     named.
     """
 
-    def __init__(self, context: ASTValidationContext) -> None:
+    def __init__(self, context: ASTValidationContext):
         super().__init__(context)
         self.known_arg_names: Dict[str, NameNode] = {}
 
diff --git a/src/graphql/validation/rules/unique_directive_names.py b/src/graphql/validation/rules/unique_directive_names.py
index 5aa422a0..656c9a0f 100644
--- a/src/graphql/validation/rules/unique_directive_names.py
+++ b/src/graphql/validation/rules/unique_directive_names.py
@@ -13,7 +13,7 @@ class UniqueDirectiveNamesRule(SDLValidationRule):
     A GraphQL document is only valid if all defined directives have unique names.
     """
 
-    def __init__(self, context: SDLValidationContext) -> None:
+    def __init__(self, context: SDLValidationContext):
         super().__init__(context)
         self.known_directive_names: Dict[str, NameNode] = {}
         self.schema = context.schema
diff --git a/src/graphql/validation/rules/unique_directives_per_location.py b/src/graphql/validation/rules/unique_directives_per_location.py
index 3c9c1c57..f234eb26 100644
--- a/src/graphql/validation/rules/unique_directives_per_location.py
+++ b/src/graphql/validation/rules/unique_directives_per_location.py
@@ -17,7 +17,7 @@ class UniqueDirectivesPerLocationRule(ASTValidationRule):
 
     context: Union[ValidationContext, SDLValidationContext]
 
-    def __init__(self, context: Union[ValidationContext, SDLValidationContext]) -> None:
+    def __init__(self, context: Union[ValidationContext, SDLValidationContext]):
         super().__init__(context)
         unique_directive_map: Dict[str, bool] = {}
 
diff --git a/src/graphql/validation/rules/unique_enum_value_names.py b/src/graphql/validation/rules/unique_enum_value_names.py
index 783b3abe..7351e8b2 100644
--- a/src/graphql/validation/rules/unique_enum_value_names.py
+++ b/src/graphql/validation/rules/unique_enum_value_names.py
@@ -15,7 +15,7 @@ class UniqueEnumValueNamesRule(SDLValidationRule):
     A GraphQL enum type is only valid if all its values are uniquely named.
     """
 
-    def __init__(self, context: SDLValidationContext) -> None:
+    def __init__(self, context: SDLValidationContext):
         super().__init__(context)
         schema = context.schema
         self.existing_type_map = schema.type_map if schema else {}
diff --git a/src/graphql/validation/rules/unique_field_definition_names.py b/src/graphql/validation/rules/unique_field_definition_names.py
index 06bddbc2..a8eaafff 100644
--- a/src/graphql/validation/rules/unique_field_definition_names.py
+++ b/src/graphql/validation/rules/unique_field_definition_names.py
@@ -15,7 +15,7 @@ class UniqueFieldDefinitionNamesRule(SDLValidationRule):
     A GraphQL complex type is only valid if all its fields are uniquely named.
     """
 
-    def __init__(self, context: SDLValidationContext) -> None:
+    def __init__(self, context: SDLValidationContext):
         super().__init__(context)
         schema = context.schema
         self.existing_type_map = schema.type_map if schema else {}
diff --git a/src/graphql/validation/rules/unique_fragment_names.py b/src/graphql/validation/rules/unique_fragment_names.py
index dc1260ce..744b231b 100644
--- a/src/graphql/validation/rules/unique_fragment_names.py
+++ b/src/graphql/validation/rules/unique_fragment_names.py
@@ -13,7 +13,7 @@ class UniqueFragmentNamesRule(ASTValidationRule):
     A GraphQL document is only valid if all defined fragments have unique names.
     """
 
-    def __init__(self, context: ASTValidationContext) -> None:
+    def __init__(self, context: ASTValidationContext):
         super().__init__(context)
         self.known_fragment_names: Dict[str, NameNode] = {}
 
diff --git a/src/graphql/validation/rules/unique_input_field_names.py b/src/graphql/validation/rules/unique_input_field_names.py
index eae56c68..1241e663 100644
--- a/src/graphql/validation/rules/unique_input_field_names.py
+++ b/src/graphql/validation/rules/unique_input_field_names.py
@@ -14,7 +14,7 @@ class UniqueInputFieldNamesRule(ASTValidationRule):
     named.
     """
 
-    def __init__(self, context: ASTValidationContext) -> None:
+    def __init__(self, context: ASTValidationContext):
         super().__init__(context)
         self.known_names_stack: List[Dict[str, NameNode]] = []
         self.known_names: Dict[str, NameNode] = {}
diff --git a/src/graphql/validation/rules/unique_operation_names.py b/src/graphql/validation/rules/unique_operation_names.py
index 60295d85..defcce05 100644
--- a/src/graphql/validation/rules/unique_operation_names.py
+++ b/src/graphql/validation/rules/unique_operation_names.py
@@ -13,7 +13,7 @@ class UniqueOperationNamesRule(ASTValidationRule):
     A GraphQL document is only valid if all defined operations have unique names.
     """
 
-    def __init__(self, context: ASTValidationContext) -> None:
+    def __init__(self, context: ASTValidationContext):
         super().__init__(context)
         self.known_operation_names: Dict[str, NameNode] = {}
 
diff --git a/src/graphql/validation/rules/unique_operation_types.py b/src/graphql/validation/rules/unique_operation_types.py
index 33a1b922..f7015b5c 100644
--- a/src/graphql/validation/rules/unique_operation_types.py
+++ b/src/graphql/validation/rules/unique_operation_types.py
@@ -19,7 +19,7 @@ class UniqueOperationTypesRule(SDLValidationRule):
     A GraphQL document is only valid if it has only one type per operation.
     """
 
-    def __init__(self, context: SDLValidationContext) -> None:
+    def __init__(self, context: SDLValidationContext):
         super().__init__(context)
         schema = context.schema
         self.defined_operation_types: Dict[
diff --git a/src/graphql/validation/rules/unique_type_names.py b/src/graphql/validation/rules/unique_type_names.py
index 6cd9a3ec..bdba66ba 100644
--- a/src/graphql/validation/rules/unique_type_names.py
+++ b/src/graphql/validation/rules/unique_type_names.py
@@ -13,7 +13,7 @@ class UniqueTypeNamesRule(SDLValidationRule):
     A GraphQL document is only valid if all defined types have unique names.
     """
 
-    def __init__(self, context: SDLValidationContext) -> None:
+    def __init__(self, context: SDLValidationContext):
         super().__init__(context)
         self.known_type_names: Dict[str, NameNode] = {}
         self.schema = context.schema
diff --git a/src/graphql/validation/rules/unique_variable_names.py b/src/graphql/validation/rules/unique_variable_names.py
index 0dbf7039..3576d90f 100644
--- a/src/graphql/validation/rules/unique_variable_names.py
+++ b/src/graphql/validation/rules/unique_variable_names.py
@@ -13,7 +13,7 @@ class UniqueVariableNamesRule(ASTValidationRule):
     A GraphQL operation is only valid if all its variables are uniquely named.
     """
 
-    def __init__(self, context: ASTValidationContext) -> None:
+    def __init__(self, context: ASTValidationContext):
         super().__init__(context)
         self.known_variable_names: Dict[str, NameNode] = {}
 
diff --git a/src/graphql/validation/rules/variables_in_allowed_position.py b/src/graphql/validation/rules/variables_in_allowed_position.py
index 47e1adc2..241b6f20 100644
--- a/src/graphql/validation/rules/variables_in_allowed_position.py
+++ b/src/graphql/validation/rules/variables_in_allowed_position.py
@@ -17,7 +17,7 @@
 class VariablesInAllowedPositionRule(ValidationRule):
     """Variables passed to field arguments conform to type"""
 
-    def __init__(self, context: ValidationContext) -> None:
+    def __init__(self, context: ValidationContext):
         super().__init__(context)
         self.var_def_map: Dict[str, Any] = {}
 
diff --git a/src/graphql/validation/validation_context.py b/src/graphql/validation/validation_context.py
index 95ce4a96..128cbba0 100644
--- a/src/graphql/validation/validation_context.py
+++ b/src/graphql/validation/validation_context.py
@@ -36,7 +36,7 @@ class VariableUsageVisitor(Visitor):
 
     usages: List[VariableUsage]
 
-    def __init__(self, type_info: TypeInfo) -> None:
+    def __init__(self, type_info: TypeInfo):
         self.usages = []
         self._append_usage = self.usages.append
         self._type_info = type_info
diff --git a/tests/execution/test_parallel.py b/tests/execution/test_parallel.py
index b01e8b42..f1106f2e 100644
--- a/tests/execution/test_parallel.py
+++ b/tests/execution/test_parallel.py
@@ -20,7 +20,7 @@
 class Barrier:
     """Barrier that makes progress only after a certain number of waits."""
 
-    def __init__(self, number: int) -> None:
+    def __init__(self, number: int):
         self.event = asyncio.Event()
         self.number = number
 
diff --git a/tests/test_user_registry.py b/tests/test_user_registry.py
index de4a8ed4..5038233e 100644
--- a/tests/test_user_registry.py
+++ b/tests/test_user_registry.py
@@ -53,7 +53,7 @@ class MutationEnum(Enum):
 class UserRegistry:
     """"Simulation of a user registry with asynchronous database backend access."""
 
-    def __init__(self, **users) -> None:
+    def __init__(self, **users):
         self._registry: Dict[str, User] = users
         self._emitter = EventEmitter()