diff --git a/src/accounting/account/commands.py b/src/accounting/account/commands.py
index b7abbe7..f30c80a 100644
--- a/src/accounting/account/commands.py
+++ b/src/accounting/account/commands.py
@@ -17,15 +17,15 @@
 """The console commands for the account management.
 
 """
-import typing as t
 from secrets import randbelow
+from typing import Any
 
 import click
+import sqlalchemy as sa
 
 from accounting import db
 from accounting.models import BaseAccount, Account, AccountL10n
 from accounting.utils.user import get_user_pk
-import sqlalchemy as sa
 
 AccountData = tuple[int, str, int, str, str, str, bool]
 """The format of the account data, as a list of (ID, base account code, number,
@@ -63,8 +63,8 @@ def init_accounts_command(username: str) -> None:
                 existing_id.add(new_id)
                 return new_id
 
-    data: list[dict[str, t.Any]] = []
-    l10n_data: list[dict[str, t.Any]] = []
+    data: list[dict[str, Any]] = []
+    l10n_data: list[dict[str, Any]] = []
     for base in bases_to_add:
         l10n: dict[str, str] = {x.locale: x.title for x in base.l10n}
         account_id: int = get_new_id()
diff --git a/src/accounting/currency/commands.py b/src/accounting/currency/commands.py
index 0c2541b..1ff9a85 100644
--- a/src/accounting/currency/commands.py
+++ b/src/accounting/currency/commands.py
@@ -18,7 +18,7 @@
 
 """
 import csv
-import typing as t
+from typing import Any
 
 import sqlalchemy as sa
 
@@ -39,11 +39,11 @@ def init_currencies_command(username: str) -> None:
         return
 
     creator_pk: int = get_user_pk(username)
-    currency_data: list[dict[str, t.Any]] = [{"code": x["code"],
-                                              "name_l10n": x["name"],
-                                              "created_by_id": creator_pk,
-                                              "updated_by_id": creator_pk}
-                                             for x in to_add]
+    currency_data: list[dict[str, Any]] = [{"code": x["code"],
+                                            "name_l10n": x["name"],
+                                            "created_by_id": creator_pk,
+                                            "updated_by_id": creator_pk}
+                                           for x in to_add]
     locales: list[str] = [x[5:] for x in to_add[0] if x.startswith("l10n-")]
     l10n_data: list[dict[str, str]] = [{"currency_code": x["code"],
                                         "locale": y,
diff --git a/src/accounting/journal_entry/forms/journal_entry.py b/src/accounting/journal_entry/forms/journal_entry.py
index 67df10f..c75fc92 100644
--- a/src/accounting/journal_entry/forms/journal_entry.py
+++ b/src/accounting/journal_entry/forms/journal_entry.py
@@ -18,8 +18,8 @@
 
 """
 import datetime as dt
-import typing as t
 from abc import ABC, abstractmethod
+from typing import TypeVar, Generic, Type
 
 import sqlalchemy as sa
 from flask_babel import LazyString
@@ -29,13 +29,13 @@ from wtforms import DateField, FieldList, FormField, TextAreaField, \
 from wtforms.validators import DataRequired, ValidationError
 
 from accounting import db
+from accounting.journal_entry.utils.account_option import AccountOption
+from accounting.journal_entry.utils.description_editor import DescriptionEditor
+from accounting.journal_entry.utils.original_line_items import \
+    get_selectable_original_line_items
 from accounting.locale import lazy_gettext
 from accounting.models import JournalEntry, Account, JournalEntryLineItem, \
     JournalEntryCurrency
-from accounting.journal_entry.utils.account_option import AccountOption
-from accounting.journal_entry.utils.original_line_items import \
-    get_selectable_original_line_items
-from accounting.journal_entry.utils.description_editor import DescriptionEditor
 from accounting.utils.random_id import new_id
 from accounting.utils.strip_text import strip_multiline_text
 from accounting.utils.user import get_current_user_pk
@@ -123,7 +123,7 @@ class JournalEntryForm(FlaskForm):
         super().__init__(*args, **kwargs)
         self.is_modified: bool = False
         """Whether the journal entry is modified during populate_obj()."""
-        self.collector: t.Type[LineItemCollector] = LineItemCollector
+        self.collector: Type[LineItemCollector] = LineItemCollector
         """The line item collector.  The default is the base abstract
         collector only to provide the correct type.  The subclass forms should
         provide their own collectors."""
@@ -155,7 +155,7 @@ class JournalEntryForm(FlaskForm):
         self.__set_date(obj, self.date.data)
         obj.note = self.note.data
 
-        collector_cls: t.Type[LineItemCollector] = self.collector
+        collector_cls: Type[LineItemCollector] = self.collector
         collector: collector_cls = collector_cls(self, obj)
         collector.collect()
 
@@ -309,11 +309,11 @@ class JournalEntryForm(FlaskForm):
         return db.session.scalar(select)
 
 
-T = t.TypeVar("T", bound=JournalEntryForm)
+T = TypeVar("T", bound=JournalEntryForm)
 """A journal entry form variant."""
 
 
-class LineItemCollector(t.Generic[T], ABC):
+class LineItemCollector(Generic[T], ABC):
     """The line item collector."""
 
     def __init__(self, form: T, obj: JournalEntry):
diff --git a/src/accounting/journal_entry/utils/description_editor.py b/src/accounting/journal_entry/utils/description_editor.py
index 193bfaf..b3ad773 100644
--- a/src/accounting/journal_entry/utils/description_editor.py
+++ b/src/accounting/journal_entry/utils/description_editor.py
@@ -18,7 +18,7 @@
 
 """
 import re
-import typing as t
+from typing import Literal
 
 import sqlalchemy as sa
 
@@ -124,12 +124,12 @@ class DescriptionTag:
 class DescriptionType:
     """A description type"""
 
-    def __init__(self, type_id: t.Literal["general", "travel", "bus"]):
+    def __init__(self, type_id: Literal["general", "travel", "bus"]):
         """Constructs a description type.
 
         :param type_id: The type ID, either "general", "travel", or "bus".
         """
-        self.id: t.Literal["general", "travel", "bus"] = type_id
+        self.id: Literal["general", "travel", "bus"] = type_id
         """The type ID."""
         self.__tag_dict: dict[str, DescriptionTag] = {}
         """A dictionary from the tag name to their corresponding tag."""
@@ -181,12 +181,12 @@ class DescriptionRecurring:
 class DescriptionDebitCredit:
     """The description on debit or credit."""
 
-    def __init__(self, debit_credit: t.Literal["debit", "credit"]):
+    def __init__(self, debit_credit: Literal["debit", "credit"]):
         """Constructs the description on debit or credit.
 
         :param debit_credit: Either "debit" or "credit".
         """
-        self.debit_credit: t.Literal["debit", "credit"] = debit_credit
+        self.debit_credit: Literal["debit", "credit"] = debit_credit
         """Either debit or credit."""
         self.general: DescriptionType = DescriptionType("general")
         """The general tags."""
@@ -194,14 +194,14 @@ class DescriptionDebitCredit:
         """The travel tags."""
         self.bus: DescriptionType = DescriptionType("bus")
         """The bus tags."""
-        self.__type_dict: dict[t.Literal["general", "travel", "bus"],
+        self.__type_dict: dict[Literal["general", "travel", "bus"],
                                DescriptionType] \
             = {x.id: x for x in {self.general, self.travel, self.bus}}
         """A dictionary from the type ID to the corresponding tags."""
         self.recurring: list[DescriptionRecurring] = []
         """The recurring transactions."""
 
-    def add_tag(self, tag_type: t.Literal["general", "travel", "bus"],
+    def add_tag(self, tag_type: Literal["general", "travel", "bus"],
                 name: str, account: Account, freq: int) -> None:
         """Adds a tag.
 
@@ -278,7 +278,7 @@ class DescriptionEditor:
         accounts: dict[int, Account] \
             = {x.id: x for x in Account.query
                .filter(Account.id.in_({x.account_id for x in result})).all()}
-        debit_credit_dict: dict[t.Literal["debit", "credit"],
+        debit_credit_dict: dict[Literal["debit", "credit"],
                                 DescriptionDebitCredit] \
             = {x.debit_credit: x for x in {self.debit, self.credit}}
         for row in result:
diff --git a/src/accounting/journal_entry/utils/operators.py b/src/accounting/journal_entry/utils/operators.py
index e4e8c35..8915e36 100644
--- a/src/accounting/journal_entry/utils/operators.py
+++ b/src/accounting/journal_entry/utils/operators.py
@@ -17,19 +17,19 @@
 """The operators for different journal entry types.
 
 """
-import typing as t
 from abc import ABC, abstractmethod
+from typing import Type
 
 from flask import render_template, request, abort
 from flask_wtf import FlaskForm
 
-from accounting.models import JournalEntry
-from accounting.template_globals import default_currency_code
-from accounting.utils.journal_entry_types import JournalEntryType
 from accounting.journal_entry.forms import JournalEntryForm, \
     CashReceiptJournalEntryForm, CashDisbursementJournalEntryForm, \
     TransferJournalEntryForm
 from accounting.journal_entry.forms.line_item import LineItemForm
+from accounting.models import JournalEntry
+from accounting.template_globals import default_currency_code
+from accounting.utils.journal_entry_types import JournalEntryType
 
 
 class JournalEntryOperator(ABC):
@@ -39,7 +39,7 @@ class JournalEntryOperator(ABC):
 
     @property
     @abstractmethod
-    def form(self) -> t.Type[JournalEntryForm]:
+    def form(self) -> Type[JournalEntryForm]:
         """Returns the form class.
 
         :return: The form class.
@@ -100,7 +100,7 @@ class CashReceiptJournalEntry(JournalEntryOperator):
     """The order when checking the journal entry operator."""
 
     @property
-    def form(self) -> t.Type[JournalEntryForm]:
+    def form(self) -> Type[JournalEntryForm]:
         """Returns the form class.
 
         :return: The form class.
@@ -170,7 +170,7 @@ class CashDisbursementJournalEntry(JournalEntryOperator):
     """The order when checking the journal entry operator."""
 
     @property
-    def form(self) -> t.Type[JournalEntryForm]:
+    def form(self) -> Type[JournalEntryForm]:
         """Returns the form class.
 
         :return: The form class.
@@ -243,7 +243,7 @@ class TransferJournalEntry(JournalEntryOperator):
     """The order when checking the journal entry operator."""
 
     @property
-    def form(self) -> t.Type[JournalEntryForm]:
+    def form(self) -> Type[JournalEntryForm]:
         """Returns the form class.
 
         :return: The form class.
diff --git a/src/accounting/models.py b/src/accounting/models.py
index 73da749..70892ff 100644
--- a/src/accounting/models.py
+++ b/src/accounting/models.py
@@ -21,8 +21,8 @@ from __future__ import annotations
 
 import datetime as dt
 import re
-import typing as t
 from decimal import Decimal
+from typing import Type, Annotated, Self
 
 import sqlalchemy as sa
 from babel import Locale
@@ -34,16 +34,16 @@ from accounting import db
 from accounting.locale import gettext
 from accounting.utils.user import user_cls, user_pk_column
 
-timestamp: t.Type[dt.datetime] \
-    = t.Annotated[dt.datetime, mapped_column(db.DateTime(timezone=True),
-                                             server_default=db.func.now())]
+timestamp: Type[dt.datetime] \
+    = Annotated[dt.datetime, mapped_column(db.DateTime(timezone=True),
+                                           server_default=db.func.now())]
 """The timestamp."""
-user_pk: t.Type[int] \
-    = t.Annotated[int, mapped_column(db.ForeignKey(user_pk_column,
-                                                   onupdate="CASCADE"))]
+user_pk: Type[int] \
+    = Annotated[int, mapped_column(db.ForeignKey(user_pk_column,
+                                                 onupdate="CASCADE"))]
 """The user primary key."""
-random_pk: t.Type[int] \
-    = t.Annotated[int, mapped_column(primary_key=True, autoincrement=False)]
+random_pk: Type[int] \
+    = Annotated[int, mapped_column(primary_key=True, autoincrement=False)]
 """The random primary key."""
 
 
@@ -273,11 +273,11 @@ class Account(db.Model):
         :return: None.
         """
         AccountL10n.query.filter(AccountL10n.account == self).delete()
-        cls: t.Type[t.Self] = self.__class__
+        cls: Type[Self] = self.__class__
         cls.query.filter(cls.id == self.id).delete()
 
     @classmethod
-    def find_by_code(cls, code: str) -> t.Self | None:
+    def find_by_code(cls, code: str) -> Self | None:
         """Finds an account by its code.
 
         :param code: The code.
@@ -290,7 +290,7 @@ class Account(db.Model):
                                 cls.no == int(m.group(2))).first()
 
     @classmethod
-    def selectable_debit(cls) -> list[t.Self]:
+    def selectable_debit(cls) -> list[Self]:
         """Returns the selectable debit accounts.
         Payable line items can not start from debit.
 
@@ -313,7 +313,7 @@ class Account(db.Model):
             .order_by(cls.base_code, cls.no).all()
 
     @classmethod
-    def selectable_credit(cls) -> list[t.Self]:
+    def selectable_credit(cls) -> list[Self]:
         """Returns the selectable debit accounts.
         Receivable line items can not start from credit.
 
@@ -335,7 +335,7 @@ class Account(db.Model):
             .order_by(cls.base_code, cls.no).all()
 
     @classmethod
-    def cash(cls) -> t.Self:
+    def cash(cls) -> Self:
         """Returns the cash account.
 
         :return: The cash account
@@ -343,7 +343,7 @@ class Account(db.Model):
         return cls.find_by_code(cls.CASH_CODE)
 
     @classmethod
-    def accumulated_change(cls) -> t.Self:
+    def accumulated_change(cls) -> Self:
         """Returns the accumulated-change account.
 
         :return: The accumulated-change account
@@ -467,7 +467,7 @@ class Currency(db.Model):
         :return: None.
         """
         CurrencyL10n.query.filter(CurrencyL10n.currency == self).delete()
-        cls: t.Type[t.Self] = self.__class__
+        cls: Type[Self] = self.__class__
         cls.query.filter(cls.code == self.code).delete()
 
 
@@ -797,14 +797,14 @@ class JournalEntryLineItem(db.Model):
         setattr(self, "__balance", value)
 
     @property
-    def offsets(self) -> list[t.Self]:
+    def offsets(self) -> list[Self]:
         """Returns the offset items.
 
         :return: The offset items.
         """
         if not hasattr(self, "__offsets"):
-            cls: t.Type[t.Self] = self.__class__
-            offsets: list[t.Self] = cls.query.join(JournalEntry)\
+            cls: Type[Self] = self.__class__
+            offsets: list[Self] = cls.query.join(JournalEntry)\
                 .filter(JournalEntryLineItem.original_line_item_id == self.id)\
                 .order_by(JournalEntry.date, JournalEntry.no,
                           cls.is_debit, cls.no).all()
@@ -831,7 +831,7 @@ class JournalEntryLineItem(db.Model):
         setattr(self, "__is_offset", value)
 
     @property
-    def match(self) -> t.Self | None:
+    def match(self) -> Self | None:
         """Returns the match of the line item.
 
         :return: The match of the line item.
@@ -841,7 +841,7 @@ class JournalEntryLineItem(db.Model):
         return getattr(self, "__match")
 
     @match.setter
-    def match(self, value: t.Self) -> None:
+    def match(self, value: Self) -> None:
         """Sets the match of the line item.
 
         :param value: The matcho of the line item.
diff --git a/src/accounting/report/period/chooser.py b/src/accounting/report/period/chooser.py
index 11b43d8..4fd4f14 100644
--- a/src/accounting/report/period/chooser.py
+++ b/src/accounting/report/period/chooser.py
@@ -21,7 +21,7 @@ This file is largely taken from the NanoParma ERP project, first written in
 
 """
 import datetime as dt
-import typing as t
+from collections.abc import Callable
 
 from accounting.models import JournalEntry
 from .period import Period
@@ -32,13 +32,13 @@ from .shortcuts import ThisMonth, LastMonth, SinceLastMonth, ThisYear, \
 class PeriodChooser:
     """The period chooser."""
 
-    def __init__(self, get_url: t.Callable[[Period], str]):
+    def __init__(self, get_url: Callable[[Period], str]):
         """Constructs a period chooser.
 
         :param get_url: The callback to return the URL of the current report in
             a period.
         """
-        self.__get_url: t.Callable[[Period], str] = get_url
+        self.__get_url: Callable[[Period], str] = get_url
         """The callback to return the URL of the current report in a period."""
 
         # Shortcut periods
diff --git a/src/accounting/report/period/parser.py b/src/accounting/report/period/parser.py
index 338393e..2bfe028 100644
--- a/src/accounting/report/period/parser.py
+++ b/src/accounting/report/period/parser.py
@@ -20,7 +20,8 @@
 import calendar
 import datetime as dt
 import re
-import typing as t
+from collections.abc import Callable
+from typing import Type
 
 from .period import Period
 from .shortcuts import ThisMonth, LastMonth, SinceLastMonth, ThisYear, \
@@ -39,7 +40,7 @@ def get_period(spec: str | None = None) -> Period:
     """
     if spec is None:
         return ThisMonth()
-    named_periods: dict[str, t.Type[t.Callable[[], Period]]] = {
+    named_periods: dict[str, Type[Callable[[], Period]]] = {
         "this-month": lambda: ThisMonth(),
         "last-month": lambda: LastMonth(),
         "since-last-month": lambda: SinceLastMonth(),
diff --git a/src/accounting/report/period/period.py b/src/accounting/report/period/period.py
index a8dcbab..2ac899f 100644
--- a/src/accounting/report/period/period.py
+++ b/src/accounting/report/period/period.py
@@ -21,7 +21,7 @@ This file is largely taken from the NanoParma ERP project, first written in
 
 """
 import datetime as dt
-import typing as t
+from typing import Self
 
 from .description import get_desc
 from .month_end import month_end
@@ -119,7 +119,7 @@ class Period:
             and not self.is_a_day
 
     @property
-    def before(self) -> t.Self | None:
+    def before(self) -> Self | None:
         """Returns the period before this period.
 
         :return: The period before this period.
diff --git a/src/accounting/report/utils/base_page_params.py b/src/accounting/report/utils/base_page_params.py
index 6b608c4..f60766b 100644
--- a/src/accounting/report/utils/base_page_params.py
+++ b/src/accounting/report/utils/base_page_params.py
@@ -17,8 +17,9 @@
 """The page parameters of a report.
 
 """
-import typing as t
 from abc import ABC, abstractmethod
+from collections.abc import Callable
+from typing import Type
 from urllib.parse import urlparse, ParseResult, parse_qsl, urlencode, \
     urlunparse
 
@@ -52,7 +53,7 @@ class BasePageParams(ABC):
         """
 
     @property
-    def journal_entry_types(self) -> t.Type[JournalEntryType]:
+    def journal_entry_types(self) -> Type[JournalEntryType]:
         """Returns the journal entry types.
 
         :return: The journal entry types.
@@ -72,7 +73,7 @@ class BasePageParams(ABC):
         return urlunparse(parts)
 
     @staticmethod
-    def _get_currency_options(get_url: t.Callable[[Currency], str],
+    def _get_currency_options(get_url: Callable[[Currency], str],
                               active_currency: Currency) -> list[OptionLink]:
         """Returns the currency options.
 
diff --git a/src/accounting/report/utils/report_chooser.py b/src/accounting/report/utils/report_chooser.py
index f79420e..57da226 100644
--- a/src/accounting/report/utils/report_chooser.py
+++ b/src/accounting/report/utils/report_chooser.py
@@ -21,7 +21,7 @@ This file is largely taken from the NanoParma ERP project, first written in
 
 """
 import re
-import typing as t
+from collections.abc import Iterator
 
 from flask_babel import LazyString
 
@@ -190,7 +190,7 @@ class ReportChooser:
                           self.__active_report == ReportType.UNMATCHED,
                           fa_icon="fa-solid fa-file-circle-question")
 
-    def __iter__(self) -> t.Iterator[OptionLink]:
+    def __iter__(self) -> Iterator[OptionLink]:
         """Returns the iteration of the reports.
 
         :return: The iteration of the reports.
diff --git a/src/accounting/template_filters.py b/src/accounting/template_filters.py
index 7d93f23..8005911 100644
--- a/src/accounting/template_filters.py
+++ b/src/accounting/template_filters.py
@@ -18,8 +18,8 @@
 
 """
 import datetime as dt
-import typing as t
 from decimal import Decimal
+from typing import Any
 
 from flask_babel import get_locale
 
@@ -71,7 +71,7 @@ def format_date(value: dt.date) -> str:
     return "{}/{}({})".format(value.month, value.day, weekday)
 
 
-def default(value: t.Any, default_value: t.Any = "") -> t.Any:
+def default(value: Any, default_value: Any = "") -> Any:
     """Returns the default value if the given value is None.
 
     :param value: The value.
diff --git a/src/accounting/utils/cast.py b/src/accounting/utils/cast.py
index 6317888..9ebfa0a 100644
--- a/src/accounting/utils/cast.py
+++ b/src/accounting/utils/cast.py
@@ -20,10 +20,10 @@ warnings from the IDE.
 This module should not import any other module from the application.
 
 """
-import typing as t
+from typing import Any
 
 
-def s(message: t.Any) -> str:
+def s(message: Any) -> str:
     """Casts the LazyString message to the string type.
 
     :param message: The message.
diff --git a/src/accounting/utils/current_account.py b/src/accounting/utils/current_account.py
index ff5bd09..25b0245 100644
--- a/src/accounting/utils/current_account.py
+++ b/src/accounting/utils/current_account.py
@@ -17,12 +17,13 @@
 """The current assets and liabilities account.
 
 """
-import typing as t
+from typing import Self
+
+import sqlalchemy as sa
 
 from accounting import db
 from accounting.locale import gettext
 from accounting.models import Account
-import sqlalchemy as sa
 
 
 class CurrentAccount:
@@ -54,7 +55,7 @@ class CurrentAccount:
         return self.str
 
     @classmethod
-    def current_assets_and_liabilities(cls) -> t.Self:
+    def current_assets_and_liabilities(cls) -> Self:
         """Returns the pseudo account for all current assets and liabilities.
 
         :return: The pseudo account for all current assets and liabilities.
@@ -67,7 +68,7 @@ class CurrentAccount:
         return account
 
     @classmethod
-    def accounts(cls) -> list[t.Self]:
+    def accounts(cls) -> list[Self]:
         """Returns the current assets and liabilities accounts.
 
         :return: The current assets and liabilities accounts.
diff --git a/src/accounting/utils/flash_errors.py b/src/accounting/utils/flash_errors.py
index 527e157..ba5a849 100644
--- a/src/accounting/utils/flash_errors.py
+++ b/src/accounting/utils/flash_errors.py
@@ -19,7 +19,7 @@
 This module should not import any other module from the application.
 
 """
-import typing as t
+from typing import Any
 
 from flask import flash
 from flask_wtf import FlaskForm
@@ -34,7 +34,7 @@ def flash_form_errors(form: FlaskForm) -> None:
     __flash_errors(form.errors)
 
 
-def __flash_errors(error: t.Any) -> None:
+def __flash_errors(error: Any) -> None:
     """Flash all errors recursively.
 
     :param error: The errors.
diff --git a/src/accounting/utils/offset_alias.py b/src/accounting/utils/offset_alias.py
index 958cce0..bd32225 100644
--- a/src/accounting/utils/offset_alias.py
+++ b/src/accounting/utils/offset_alias.py
@@ -17,7 +17,7 @@
 """The SQLAlchemy alias for the offset items.
 
 """
-import typing as t
+from typing import Any
 
 import sqlalchemy as sa
 
@@ -30,10 +30,10 @@ def offset_alias() -> sa.Alias:
     :return: The SQLAlchemy alias for the offset items.
     """
 
-    def as_from(model_cls: t.Any) -> sa.FromClause:
+    def as_from(model_cls: Any) -> sa.FromClause:
         return model_cls
 
-    def as_alias(alias: t.Any) -> sa.Alias:
+    def as_alias(alias: Any) -> sa.Alias:
         return alias
 
     return as_alias(sa.alias(as_from(JournalEntryLineItem), name="offset"))
diff --git a/src/accounting/utils/pagination.py b/src/accounting/utils/pagination.py
index f2bf082..1dc375a 100644
--- a/src/accounting/utils/pagination.py
+++ b/src/accounting/utils/pagination.py
@@ -19,7 +19,7 @@
 This module should not import any other module from the application.
 
 """
-import typing as t
+from typing import TypeVar, Generic
 from urllib.parse import urlparse, parse_qsl, urlencode, urlunparse, \
     ParseResult
 
@@ -62,10 +62,10 @@ class Redirection(RequestRedirect):
 DEFAULT_PAGE_SIZE: int = 10
 """The default page size."""
 
-T = t.TypeVar("T")
+T = TypeVar("T")
 
 
-class Pagination(t.Generic[T]):
+class Pagination(Generic[T]):
     """The pagination utility."""
 
     def __init__(self, items: list[T], is_reversed: bool = False):
@@ -91,7 +91,7 @@ class Pagination(t.Generic[T]):
         """The options to the number of items in a page."""
 
 
-class AbstractPagination(t.Generic[T]):
+class AbstractPagination(Generic[T]):
     """An abstract pagination."""
 
     def __init__(self):
diff --git a/src/accounting/utils/permission.py b/src/accounting/utils/permission.py
index 459b6b6..d8f17e2 100644
--- a/src/accounting/utils/permission.py
+++ b/src/accounting/utils/permission.py
@@ -19,21 +19,21 @@
 This module should not import any other module from the application.
 
 """
-import typing as t
+from collections.abc import Callable
 
 from flask import abort, Blueprint, Response
 
 from accounting.utils.user import get_current_user, UserUtilityInterface
 
 
-def has_permission(rule: t.Callable[[], bool]) -> t.Callable:
+def has_permission(rule: Callable[[], bool]) -> Callable:
     """The permission decorator to check whether the current user is allowed.
 
     :param rule: The permission rule.
     :return: The view decorator.
     """
 
-    def decorator(view: t.Callable) -> t.Callable:
+    def decorator(view: Callable) -> Callable:
         """The view decorator to decorate a view with permission tests.
 
         :param view: The view.
@@ -61,16 +61,16 @@ def has_permission(rule: t.Callable[[], bool]) -> t.Callable:
     return decorator
 
 
-__can_view_func: t.Callable[[], bool] = lambda: True
+__can_view_func: Callable[[], bool] = lambda: True
 """The callback that returns whether the current user can view the accounting
 data."""
-__can_edit_func: t.Callable[[], bool] = lambda: True
+__can_edit_func: Callable[[], bool] = lambda: True
 """The callback that returns whether the current user can edit the accounting
 data."""
-__can_admin_func: t.Callable[[], bool] = lambda: True
+__can_admin_func: Callable[[], bool] = lambda: True
 """The callback that returns whether the current user can administrate the
 accounting settings."""
-_unauthorized_func: t.Callable[[], Response | None] \
+_unauthorized_func: Callable[[], Response | None] \
     = lambda: Response(status=403)
 """The callback that returns the response to require the user to log in."""
 
diff --git a/src/accounting/utils/random_id.py b/src/accounting/utils/random_id.py
index e3c2800..817583a 100644
--- a/src/accounting/utils/random_id.py
+++ b/src/accounting/utils/random_id.py
@@ -19,13 +19,13 @@
 This module should not import any other module from the application.
 
 """
-import typing as t
 from secrets import randbelow
+from typing import Type
 
 from accounting import db
 
 
-def new_id(cls: t.Type):
+def new_id(cls: Type):
     """Returns a new random ID for the data model.
 
     :param cls: The data model.
diff --git a/src/accounting/utils/user.py b/src/accounting/utils/user.py
index d879ac4..b5d8583 100644
--- a/src/accounting/utils/user.py
+++ b/src/accounting/utils/user.py
@@ -19,17 +19,17 @@
 This module should not import any other module from the application.
 
 """
-import typing as t
 from abc import ABC, abstractmethod
+from typing import TypeVar, Generic, Type
 
 import sqlalchemy as sa
 from flask import g, Response
 from flask_sqlalchemy.model import Model
 
-T = t.TypeVar("T", bound=Model)
+T = TypeVar("T", bound=Model)
 
 
-class UserUtilityInterface(t.Generic[T], ABC):
+class UserUtilityInterface(Generic[T], ABC):
     """The interface for the user utilities."""
 
     @abstractmethod
@@ -72,7 +72,7 @@ class UserUtilityInterface(t.Generic[T], ABC):
 
     @property
     @abstractmethod
-    def cls(self) -> t.Type[T]:
+    def cls(self) -> Type[T]:
         """Returns the class of the user data model.
 
         :return: The class of the user data model.
@@ -112,7 +112,7 @@ class UserUtilityInterface(t.Generic[T], ABC):
 
 __user_utils: UserUtilityInterface
 """The user utilities."""
-user_cls: t.Type[Model] = Model
+user_cls: Type[Model] = Model
 """The user class."""
 user_pk_column: sa.Column = sa.Column(sa.Integer)
 """The primary key column of the user class."""
diff --git a/tests/test_commands.py b/tests/test_commands.py
index 74ee287..bf32fbe 100644
--- a/tests/test_commands.py
+++ b/tests/test_commands.py
@@ -18,8 +18,8 @@
 
 """
 import csv
-import typing as t
 import unittest
+from typing import Any
 
 import sqlalchemy as sa
 from click.testing import Result
@@ -80,7 +80,7 @@ class ConsoleCommandTestCase(unittest.TestCase):
         from accounting.models import BaseAccount
 
         with open(data_dir / "base_accounts.csv") as fp:
-            data: dict[dict[str, t.Any]] \
+            data: dict[dict[str, Any]] \
                 = {x["code"]: {"code": x["code"],
                                "title": x["title"],
                                "l10n": {y[5:]: x[y]
@@ -135,7 +135,7 @@ class ConsoleCommandTestCase(unittest.TestCase):
         from accounting.models import Currency
 
         with open(data_dir / "currencies.csv") as fp:
-            data: dict[dict[str, t.Any]] \
+            data: dict[dict[str, Any]] \
                 = {x["code"]: {"code": x["code"],
                                "name": x["name"],
                                "l10n": {y[5:]: x[y]
diff --git a/tests/test_site/__init__.py b/tests/test_site/__init__.py
index 2ab46fb..fb1ec15 100644
--- a/tests/test_site/__init__.py
+++ b/tests/test_site/__init__.py
@@ -18,8 +18,8 @@
 
 """
 import os
-import typing as t
 from secrets import token_urlsafe
+from typing import Type
 
 from click.testing import Result
 from flask import Flask, Blueprint, render_template, redirect, Response, \
@@ -94,7 +94,7 @@ def create_app(is_testing: bool = False) -> Flask:
             return redirect(append_next(url_for("auth.login-form")))
 
         @property
-        def cls(self) -> t.Type[auth.User]:
+        def cls(self) -> Type[auth.User]:
             return auth.User
 
         @property
diff --git a/tests/test_site/auth.py b/tests/test_site/auth.py
index 269f00a..d661066 100644
--- a/tests/test_site/auth.py
+++ b/tests/test_site/auth.py
@@ -17,7 +17,7 @@
 """The authentication for the Mia! Accounting demonstration website.
 
 """
-import typing as t
+from collections.abc import Callable
 
 from flask import Blueprint, render_template, Flask, redirect, url_for, \
     session, request, g, Response, abort
@@ -96,7 +96,7 @@ def current_user() -> User | None:
     return g.user
 
 
-def admin_required(view: t.Callable) -> t.Callable:
+def admin_required(view: Callable) -> Callable:
     """The view decorator to require the user to be an administrator.
 
     :param view: The view.
diff --git a/tests/test_site/lib.py b/tests/test_site/lib.py
index 8e6fbdb..7e27aba 100644
--- a/tests/test_site/lib.py
+++ b/tests/test_site/lib.py
@@ -20,10 +20,10 @@
 from __future__ import annotations
 
 import datetime as dt
-import typing as t
 from abc import ABC, abstractmethod
 from decimal import Decimal
 from secrets import randbelow
+from typing import Any
 
 import sqlalchemy as sa
 from flask import Flask
@@ -193,8 +193,8 @@ class BaseTestData(ABC):
                 .filter(User.username == username).first()
             assert current_user is not None
             self.__current_user_id: int = current_user.id
-            self.__journal_entries: list[dict[str, t.Any]] = []
-            self.__line_items: list[dict[str, t.Any]] = []
+            self.__journal_entries: list[dict[str, Any]] = []
+            self.__line_items: list[dict[str, Any]] = []
             self._init_data()
 
     @abstractmethod
@@ -258,7 +258,7 @@ class BaseTestData(ABC):
                 assert account is not None
                 debit_no = debit_no + 1
                 line_item.id = self.__new_id(existing_l_id)
-                data: dict[str, t.Any] \
+                data: dict[str, Any] \
                     = {"id": line_item.id,
                        "journal_entry_id": journal_entry_data.id,
                        "is_debit": True,
@@ -277,7 +277,7 @@ class BaseTestData(ABC):
                 assert account is not None
                 credit_no = credit_no + 1
                 line_item.id = self.__new_id(existing_l_id)
-                data: dict[str, t.Any] \
+                data: dict[str, Any] \
                     = {"id": line_item.id,
                        "journal_entry_id": journal_entry_data.id,
                        "is_debit": False,
diff --git a/tests/testlib.py b/tests/testlib.py
index d8f9057..883cd2b 100644
--- a/tests/testlib.py
+++ b/tests/testlib.py
@@ -20,7 +20,7 @@
 from __future__ import annotations
 
 import re
-import typing as t
+from typing import Literal
 
 import httpx
 from flask import Flask, render_template_string
@@ -108,7 +108,7 @@ def get_client(app: Flask, username: str) -> tuple[httpx.Client, str]:
 
 
 def set_locale(client: httpx.Client, csrf_token: str,
-               locale: t.Literal["en", "zh_Hant", "zh_Hans"]) -> None:
+               locale: Literal["en", "zh_Hant", "zh_Hans"]) -> None:
     """Sets the current locale.
 
     :param client: The test client.