diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 9ea447d..61f518d 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,5 +1,5 @@
 ---
-image: s3lph/matemat-ci:20180720-01
+image: s3lph/matemat-ci:20180802-02
 
 stages:
 - test
@@ -10,8 +10,8 @@ test:
   stage: test
   script:
   - pip3 install -r requirements.txt
-  - sudo -u matemat python3-coverage run --branch -m unittest discover matemat
-  - sudo -u matemat python3-coverage report -m --include 'matemat/*' --omit '*/test_*.py'
+  - sudo -u matemat python3 -m coverage run --branch -m unittest discover matemat
+  - sudo -u matemat python3 -m coverage report -m --include 'matemat/*' --omit '*/test_*.py'
 
 codestyle:
   stage: test
diff --git a/Dockerfile b/Dockerfile
index c427a2e..553cb64 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
 
-FROM python:3.6-alpine
+FROM python:3.7-alpine
 
 RUN mkdir -p /var/matemat/db /var/matemat/upload
 RUN apk --update add libmagic
diff --git a/README.md b/README.md
index 49816f3..278c59e 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@ This project intends to provide a well-tested and maintainable alternative to
 
 ## Dependencies
 
-- Python 3 (>=3.6)
+- Python 3 (>=3.7)
 - Python dependencies:
   - file-magic
   - jinja2
diff --git a/doc b/doc
index ece840a..e52eec0 160000
--- a/doc
+++ b/doc
@@ -1 +1 @@
-Subproject commit ece840af5b19d2c78b2dbfa14adac145fab79f4f
+Subproject commit e52eec0831ef72edab816d549d7ee2a85575e292
diff --git a/matemat/db/facade.py b/matemat/db/facade.py
index 30fafbf..1c954db 100644
--- a/matemat/db/facade.py
+++ b/matemat/db/facade.py
@@ -1,4 +1,5 @@
 
+from __future__ import annotations
 from typing import List, Optional, Any, Type
 
 import crypt
@@ -9,12 +10,6 @@ from matemat.exceptions import AuthenticationError, DatabaseConsistencyError
 from matemat.db import DatabaseWrapper
 from matemat.db.wrapper import Transaction
 
-# TODO: Change to METHOD_BLOWFISH when adopting Python 3.7
-"""
-The method to use for password hashing.
-"""
-_CRYPT_METHOD = crypt.METHOD_SHA512
-
 
 class MatematDatabase(object):
     """
@@ -42,7 +37,7 @@ class MatematDatabase(object):
         """
         self.db: DatabaseWrapper = DatabaseWrapper(filename)
 
-    def __enter__(self) -> 'MatematDatabase':
+    def __enter__(self) -> MatematDatabase:
         # Pass context manager stuff through to the database wrapper
         self.db.__enter__()
         return self
@@ -116,7 +111,7 @@ class MatematDatabase(object):
         :raises ValueError: If a user with the same name already exists.
         """
         # Hash the password.
-        pwhash: str = crypt.crypt(password, crypt.mksalt(_CRYPT_METHOD))
+        pwhash: str = crypt.crypt(password, crypt.mksalt())
         user_id: int = -1
         with self.db.transaction() as c:
             # Look up whether a user with the same name already exists.
@@ -194,7 +189,7 @@ class MatematDatabase(object):
             if verify_password and not compare_digest(crypt.crypt(oldpass, row[0]), row[0]):
                 raise AuthenticationError('Old password does not match.')
             # Hash the new password and write it to the database.
-            pwhash: str = crypt.crypt(newpass, crypt.mksalt(_CRYPT_METHOD))
+            pwhash: str = crypt.crypt(newpass, crypt.mksalt())
             c.execute('''
             UPDATE users SET password = :pwhash, lastchange = STRFTIME('%s', 'now') WHERE user_id = :user_id
             ''', {
@@ -224,7 +219,7 @@ class MatematDatabase(object):
             if verify_password and not compare_digest(crypt.crypt(password, row[0]), row[0]):
                 raise AuthenticationError('Password does not match.')
             # Hash the new touchkey and write it to the database.
-            tkhash: Optional[str] = crypt.crypt(touchkey, crypt.mksalt(_CRYPT_METHOD)) if touchkey is not None else None
+            tkhash: Optional[str] = crypt.crypt(touchkey, crypt.mksalt()) if touchkey is not None else None
             c.execute('''
             UPDATE users SET touchkey = :tkhash, lastchange = STRFTIME('%s', 'now') WHERE user_id = :user_id
             ''', {
diff --git a/matemat/db/primitives/Product.py b/matemat/db/primitives/Product.py
index dd25738..18b5003 100644
--- a/matemat/db/primitives/Product.py
+++ b/matemat/db/primitives/Product.py
@@ -1,75 +1,22 @@
 
-from typing import Any
+from dataclasses import dataclass
 
 
-class Product(object):
+@dataclass
+class Product:
     """
     Representation of a product offered by the Matemat, with a name, prices for users, and the number of items
     currently in stock.
+
+    :param id: The product ID in the database.
+    :param name: The product's name.
+    :param price_member: The price of a unit of this product for users marked as "members".
+    :param price_non_member: The price of a unit of this product for users NOT marked as "members".
+    :param stock: The number of items of this product currently in stock.
     """
 
-    def __init__(self,
-                 product_id: int,
-                 name: str,
-                 price_member: int,
-                 price_non_member: int,
-                 stock: int) -> None:
-        """
-        Create  a new product instance with the given arguments.
-
-        :param product_id: The product ID in the database.
-        :param name: The product's name.
-        :param price_member: The price of a unit of this product for users marked as "members".
-        :param price_non_member: The price of a unit of this product for users NOT marked as "members".
-        :param stock: The number of items of this product currently in stock.
-        """
-        self._product_id: int = product_id
-        self._name: str = name
-        self._price_member: int = price_member
-        self._price_non_member: int = price_non_member
-        self._stock: int = stock
-
-    def __eq__(self, other: Any) -> bool:
-        if other is None or not isinstance(other, Product):
-            return False
-        return self._product_id == other._product_id \
-            and self._name == other._name \
-            and self._price_member == other._price_member \
-            and self._price_non_member == other._price_non_member \
-            and self._stock == other._stock
-
-    @property
-    def id(self) -> int:
-        return self._product_id
-
-    @property
-    def name(self) -> str:
-        return self._name
-
-    @name.setter
-    def name(self, name: str) -> None:
-        self._name = name
-
-    @property
-    def price_member(self) -> int:
-        return self._price_member
-
-    @price_member.setter
-    def price_member(self, price: int) -> None:
-        self._price_member = price
-
-    @property
-    def price_non_member(self) -> int:
-        return self._price_non_member
-
-    @price_non_member.setter
-    def price_non_member(self, price: int) -> None:
-        self._price_non_member = price
-
-    @property
-    def stock(self) -> int:
-        return self._stock
-
-    @stock.setter
-    def stock(self, stock: int) -> None:
-        self._stock = stock
+    id: int
+    name: str
+    price_member: int
+    price_non_member: int
+    stock: int
diff --git a/matemat/db/primitives/User.py b/matemat/db/primitives/User.py
index 45e026d..4d2cee6 100644
--- a/matemat/db/primitives/User.py
+++ b/matemat/db/primitives/User.py
@@ -1,87 +1,27 @@
 
-from typing import Optional, Any
+from typing import Optional
+
+from dataclasses import dataclass
 
 
-class User(object):
+@dataclass
+class User:
     """
     Representation of a user registered with the Matemat, with a name, e-mail address (optional), whether the user is a
     member of the organization the Matemat instance is used in, whether the user is an administrator, and the user's
     account balance.
+
+    :param id: The user ID in the database.
+    :param username: The user's name.
+    :param balance: The balance of the user's account.
+    :param email: The user's e-mail address (optional).
+    :param admin: Whether the user is an administrator.
+    :param member: Whether the user is a member.
     """
 
-    def __init__(self,
-                 user_id: int,
-                 username: str,
-                 balance: int,
-                 email: Optional[str] = None,
-                 admin: bool = False,
-                 member: bool = True) -> None:
-        """
-        Create  a new user instance with the given arguments.
-
-        :param user_id: The user ID in the database.
-        :param username: The user's name.
-        :param balance: The balance of the user's account.
-        :param email: The user's e-mail address (optional).
-        :param admin: Whether the user is an administrator.
-        :param member: Whether the user is a member.
-        """
-        self._user_id: int = user_id
-        self._username: str = username
-        self._email: Optional[str] = email
-        self._admin: bool = admin
-        self._member: bool = member
-        self._balance: int = balance
-
-    def __eq__(self, other: Any) -> bool:
-        if other is None or not isinstance(other, User):
-            return False
-        return self._user_id == other._user_id \
-            and self._username == other._username \
-            and self._email == other._email \
-            and self._admin == other._admin \
-            and self._member == other._member
-
-    @property
-    def id(self) -> int:
-        return self._user_id
-
-    @property
-    def name(self) -> str:
-        return self._username
-
-    @name.setter
-    def name(self, value):
-        self._username = value
-
-    @property
-    def email(self) -> Optional[str]:
-        return self._email
-
-    @email.setter
-    def email(self, email: str) -> None:
-        self._email = email
-
-    @property
-    def is_admin(self) -> bool:
-        return self._admin
-
-    @is_admin.setter
-    def is_admin(self, admin: bool) -> None:
-        self._admin = admin
-
-    @property
-    def is_member(self) -> bool:
-        return self._member
-
-    @is_member.setter
-    def is_member(self, member: bool) -> None:
-        self._member = member
-
-    @property
-    def balance(self) -> int:
-        return self._balance
-
-    @balance.setter
-    def balance(self, balance: int) -> None:
-        self._balance = balance
+    id: int
+    name: str
+    balance: int
+    email: Optional[str] = None
+    is_admin: bool = False
+    is_member: bool = False
diff --git a/matemat/db/test/test_facade.py b/matemat/db/test/test_facade.py
index 04c0eb4..d82b62c 100644
--- a/matemat/db/test/test_facade.py
+++ b/matemat/db/test/test_facade.py
@@ -71,7 +71,7 @@ class DatabaseTest(unittest.TestCase):
                 u = db.create_user('testuser', 'supersecurepassword', 'testuser@example.com')
                 # Add a touchkey without using the provided function
                 c.execute('''UPDATE users SET touchkey = :tkhash WHERE user_id = :user_id''', {
-                    'tkhash': crypt.crypt('0123', crypt.mksalt(crypt.METHOD_SHA512)),
+                    'tkhash': crypt.crypt('0123', crypt.mksalt()),
                     'user_id': u.id
                 })
             user = db.login('testuser', 'supersecurepassword')
@@ -112,7 +112,7 @@ class DatabaseTest(unittest.TestCase):
             with self.assertRaises(AuthenticationError):
                 db.login('testuser', 'mynewpassword')
             db.login('testuser', 'adminpasswordreset')
-            user._user_id = -1
+            user.id = -1
             with self.assertRaises(AuthenticationError):
                 # Password change for an inexistent user should fail
                 db.change_password(user, 'adminpasswordreset', 'passwordwithoutuser')
@@ -136,7 +136,7 @@ class DatabaseTest(unittest.TestCase):
             with self.assertRaises(AuthenticationError):
                 db.login('testuser', touchkey='4567')
             db.login('testuser', touchkey='89ab')
-            user._user_id = -1
+            user.id = -1
             with self.assertRaises(AuthenticationError):
                 # Touchkey change for an inexistent user should fail
                 db.change_touchkey(user, '89ab', '048c')
@@ -157,7 +157,7 @@ class DatabaseTest(unittest.TestCase):
             self.assertFalse(checkuser.is_admin)
             self.assertFalse(checkuser.is_member)
             self.assertEqual(4200, checkuser.balance)
-            user._user_id = -1
+            user.id = -1
             with self.assertRaises(DatabaseConsistencyError):
                 db.change_user(user, agent, is_member='True')
 
@@ -238,7 +238,7 @@ class DatabaseTest(unittest.TestCase):
             self.assertEqual(150, checkproduct.price_member)
             self.assertEqual(250, checkproduct.price_non_member)
             self.assertEqual(42, checkproduct.stock)
-            product._product_id = -1
+            product.id = -1
             with self.assertRaises(DatabaseConsistencyError):
                 db.change_product(product)
             product2 = db.create_product('Club Mate', 200, 200)
@@ -281,7 +281,7 @@ class DatabaseTest(unittest.TestCase):
                 with self.assertRaises(ValueError):
                     # Should fail, negative amount
                     db.deposit(user, -42)
-                user._user_id = -1
+                user.id = -1
                 with self.assertRaises(DatabaseConsistencyError):
                     # Should fail, user id -1 does not exist
                     db.deposit(user, 42)
@@ -300,7 +300,7 @@ class DatabaseTest(unittest.TestCase):
                 self.assertEqual(42, c.fetchone()[0])
                 c.execute('''SELECT stock FROM products WHERE product_id = ?''', [product2.id])
                 self.assertEqual(0, c.fetchone()[0])
-                product._product_id = -1
+                product.id = -1
                 with self.assertRaises(DatabaseConsistencyError):
                     # Should fail, product id -1 does not exist
                     db.restock(product, 42)
diff --git a/matemat/db/wrapper.py b/matemat/db/wrapper.py
index c0cddc4..fcf85e7 100644
--- a/matemat/db/wrapper.py
+++ b/matemat/db/wrapper.py
@@ -1,4 +1,5 @@
 
+from __future__ import annotations
 from typing import Any, Optional
 
 import sqlite3
@@ -48,7 +49,7 @@ class DatabaseWrapper(object):
         self._filename: str = filename
         self._sqlite_db: Optional[sqlite3.Connection] = None
 
-    def __enter__(self) -> 'DatabaseWrapper':
+    def __enter__(self) -> DatabaseWrapper:
         self.connect()
         return self
 
diff --git a/matemat/webserver/requestargs.py b/matemat/webserver/requestargs.py
index 373db90..6ce11ef 100644
--- a/matemat/webserver/requestargs.py
+++ b/matemat/webserver/requestargs.py
@@ -1,4 +1,5 @@
 
+from __future__ import annotations
 from typing import Dict, Iterator, List, Tuple, Union
 
 
@@ -24,7 +25,7 @@ class RequestArguments(object):
         """
         self.__container: Dict[str, RequestArgument] = dict()
 
-    def __getitem__(self, key: str) -> 'RequestArgument':
+    def __getitem__(self, key: str) -> RequestArgument:
         """
         Retrieve the argument for the given name, creating it on the fly, if it doesn't exist.
 
@@ -40,7 +41,7 @@ class RequestArguments(object):
         # Return the argument for the name
         return self.__container[key]
 
-    def __getattr__(self, key: str) -> 'RequestArgument':
+    def __getattr__(self, key: str) -> RequestArgument:
         """
         Syntactic sugar for accessing values with a name that can be used in Python attributes.  The value will be
         returned as an immutable view.
@@ -278,7 +279,7 @@ class RequestArgument(object):
             # Yield an immutable scalar view for each (ctype, value) element in the array
             yield _View(self.__name, v)
 
-    def __getitem__(self, index: Union[int, slice]) -> 'RequestArgument':
+    def __getitem__(self, index: Union[int, slice]) -> RequestArgument:
         """
         Index the argument with either an int or a slice.  The returned values are represented as immutable
         RequestArgument views.
diff --git a/testing/Dockerfile b/testing/Dockerfile
index 94644e6..a67d602 100644
--- a/testing/Dockerfile
+++ b/testing/Dockerfile
@@ -1,11 +1,15 @@
 
-FROM debian:buster
+# There is no buster image yet and stretch doesn't have a docker package.  So let's just "upgrade" the image to buster.
+FROM python:3.7-stretch
 
-RUN useradd -d /home/matemat -m matemat
-RUN mkdir -p /var/matemat/db && chown matemat:matemat -R /var/matemat/db
-RUN mkdir -p /var/matemat/upload && chown matemat:matemat -R /var/matemat/upload
-RUN apt-get update -qy
-RUN apt-get install -y --no-install-recommends file sudo openssh-client git docker.io python3-dev python3-pip python3-coverage python3-setuptools build-essential
-RUN pip3 install wheel pycodestyle mypy
+RUN sed -re 's/stretch/buster/g' -i /etc/apt/sources.list \
+  && useradd -d /home/matemat -m matemat \
+  && mkdir -p /var/matemat/db /var/matemat/upload \
+  && chown matemat:matemat -R /var/matemat/db \
+  && chown matemat:matemat -R /var/matemat/upload \
+  && apt-get update -qy \
+  && apt-get install -y --no-install-recommends file sudo openssh-client git docker.io build-essential \
+  && python3.7 -m pip install coverage wheel pycodestyle mypy \
+  && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /home/matemat