diff --git a/app/models/anonymous_user.py b/app/models/anonymous_user.py
index d82abd9..76f99f7 100644
--- a/app/models/anonymous_user.py
+++ b/app/models/anonymous_user.py
@@ -1,17 +1,17 @@
 class AnonymouseUser:
     id = None
 
-    def is_active(self):
+    def is_active(self) -> bool:
         return False
 
-    def is_authenticated(self):
+    def is_authenticated(self) -> bool:
         return False
 
-    def is_anonymous(self):
+    def is_anonymous(self) -> bool:
         return True
 
-    def is_admin(self):
+    def is_admin(self) -> bool:
         return False
 
-    def get_id(self):
+    def get_id(self) -> None:
         return None
diff --git a/app/models/location.py b/app/models/location.py
index 73946e7..8fc3a92 100644
--- a/app/models/location.py
+++ b/app/models/location.py
@@ -1,3 +1,5 @@
+import typing
+
 from models import db
 
 
@@ -10,11 +12,12 @@ class Location(db.Model):
     products = db.relationship("Product", backref="location", lazy="dynamic")
     orders = db.relationship("Order", backref="location", lazy="dynamic")
 
-    def configure(self, name, address, telephone, website):
+    def configure(self, name: str, address: str,
+                  telephone: typing.Optional[str], website: str) -> None:
         self.name = name
         self.address = address
         self.website = website
         self.telephone = telephone
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return "%s" % (self.name)
diff --git a/app/models/order.py b/app/models/order.py
index 0c804ec..b9c2b1a 100644
--- a/app/models/order.py
+++ b/app/models/order.py
@@ -1,6 +1,8 @@
+import typing
 from datetime import datetime
 
 from .database import db
+from .location import Location
 from .user import User
 
 
@@ -13,34 +15,34 @@ class Order(db.Model):
     public = db.Column(db.Boolean, default=True)
     items = db.relationship("OrderItem", backref="order", lazy="dynamic")
 
-    def configure(self, courrier, location, starttime, stoptime):
+    def configure(self, courrier: User, location: Location,
+                  starttime: db.DateTime, stoptime: db.DateTime) -> None:
         self.courrier = courrier
         self.location = location
         self.starttime = starttime
         self.stoptime = stoptime
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         if self.location:
             return "Order %d @ %s" % (self.id, self.location.name or "None")
         else:
             return "Order %d" % (self.id)
 
-    def group_by_user(self):
-        group = dict()
+    def group_by_user(self) -> typing.Dict[str, typing.Any]:
+        group: typing.Dict[str, typing.Any] = dict()
         for item in self.items:
             user = group.get(item.get_name(), dict())
             user["total"] = user.get("total", 0) + item.product.price
-            user["to_pay"] = (
-                user.get("to_pay", 0) + item.product.price if not item.paid else 0
-            )
+            user["to_pay"] = (user.get("to_pay", 0) + item.product.price if
+                              not item.paid else 0)
             user["paid"] = user.get("paid", True) and item.paid
             user["products"] = user.get("products", []) + [item.product]
             group[item.get_name()] = user
 
         return group
 
-    def group_by_product(self):
-        group = dict()
+    def group_by_product(self) -> typing.Dict[str, typing.Any]:
+        group: typing.Dict[str, typing.Any] = dict()
         for item in self.items:
             product = group.get(item.product.name, dict())
             product["count"] = product.get("count", 0) + 1
@@ -50,7 +52,7 @@ class Order(db.Model):
 
         return group
 
-    def can_close(self, user_id):
+    def can_close(self, user_id: int) -> bool:
         if self.stoptime and self.stoptime < datetime.now():
             return False
         user = None
diff --git a/app/models/orderitem.py b/app/models/orderitem.py
index 0ea982e..d699a90 100644
--- a/app/models/orderitem.py
+++ b/app/models/orderitem.py
@@ -1,6 +1,8 @@
 from datetime import datetime
 
 from .database import db
+from .order import Order
+from .product import Product
 from .user import User
 
 
@@ -17,17 +19,17 @@ class OrderItem(db.Model):
     extra = db.Column(db.String(254), nullable=True)
     name = db.Column(db.String(120))
 
-    def configure(self, user, order, product):
+    def configure(self, user: User, order: Order, product: Product) -> None:
         self.user = user
         self.order = order
         self.product = product
 
-    def get_name(self):
+    def get_name(self) -> str:
         if self.user_id is not None and self.user_id > 0:
             return self.user.username
         return self.name
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         product_name = None
         if self.product:
             product_name = self.product.name
@@ -37,7 +39,7 @@ class OrderItem(db.Model):
             product_name or "None",
         )
 
-    def can_delete(self, order_id, user_id, name):
+    def can_delete(self, order_id: int, user_id: int, name: str) -> bool:
         if int(self.order_id) != int(order_id):
             return False
         if self.order.stoptime and self.order.stoptime < datetime.now():
diff --git a/app/models/product.py b/app/models/product.py
index 21e4008..909aade 100644
--- a/app/models/product.py
+++ b/app/models/product.py
@@ -1,19 +1,22 @@
 from models import db
 
+from .location import Location
+
 
 class Product(db.Model):
     id = db.Column(db.Integer, primary_key=True)
     location_id = db.Column(db.Integer, db.ForeignKey("location.id"))
     name = db.Column(db.String(120), nullable=False)
     price = db.Column(db.Integer, nullable=False)
-    orderItems = db.relationship("OrderItem", backref="product", lazy="dynamic")
+    orderItems = db.relationship("OrderItem",
+                                 backref="product", lazy="dynamic")
 
-    def configure(self, location, name, price):
+    def configure(self, location: Location, name: str, price: int) -> None:
         self.location = location
         self.name = name
         self.price = price
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return "%s (€%d)from %s" % (
             self.name,
             self.price / 100,
diff --git a/app/models/user.py b/app/models/user.py
index 93362d1..4ed2fe8 100644
--- a/app/models/user.py
+++ b/app/models/user.py
@@ -14,25 +14,25 @@ class User(db.Model):
     )
     orderItems = db.relationship("OrderItem", backref="user", lazy="dynamic")
 
-    def configure(self, username, admin, bias):
+    def configure(self, username: str, admin: bool, bias: int) -> None:
         self.username = username
         self.admin = admin
         self.bias = bias
 
-    def is_authenticated(self):
+    def is_authenticated(self) -> bool:
         return True
 
-    def is_active(self):
+    def is_active(self) -> bool:
         return True
 
-    def is_admin(self):
+    def is_admin(self) -> bool:
         return self.admin
 
-    def is_anonymous(self):
+    def is_anonymous(self) -> bool:
         return False
 
-    def get_id(self):
+    def get_id(self) -> str:
         return str(self.id)
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return "%s" % self.username