diff --git a/ihatemoney/api/common.py b/ihatemoney/api/common.py
index ede76e46..fa097dec 100644
--- a/ihatemoney/api/common.py
+++ b/ihatemoney/api/common.py
@@ -35,7 +35,9 @@ def need_auth(f):
                 auth_token = auth_header.split(" ")[1]
             except IndexError:
                 abort(401)
-            project_id = Project.verify_token(auth_token, token_type="non_timed_token")
+            project_id = Project.verify_token(
+                auth_token, token_type="auth", project_id=project_id
+            )
             if auth_token and project_id:
                 project = Project.query.get(project_id)
                 if project:
diff --git a/ihatemoney/models.py b/ihatemoney/models.py
index 68d1fd84..b3d1cba2 100644
--- a/ihatemoney/models.py
+++ b/ihatemoney/models.py
@@ -7,8 +7,8 @@ from flask_sqlalchemy import BaseQuery, SQLAlchemy
 from itsdangerous import (
     BadSignature,
     SignatureExpired,
-    TimedJSONWebSignatureSerializer,
     URLSafeSerializer,
+    URLSafeTimedSerializer,
 )
 import sqlalchemy
 from sqlalchemy import orm
@@ -339,41 +339,61 @@ class Project(db.Model):
         db.session.delete(self)
         db.session.commit()
 
-    def generate_token(self, expiration=0):
+    def generate_token(self, token_type="auth"):
         """Generate a timed and serialized JsonWebToken
 
-        :param expiration: Token expiration time (in seconds)
+        :param token_type: Either "auth" for authentication (invalidated when project code changed),
+                        or "reset" for password reset (invalidated after expiration)
         """
-        if expiration:
-            serializer = TimedJSONWebSignatureSerializer(
-                current_app.config["SECRET_KEY"], expiration
+
+        if token_type == "reset":
+            serializer = URLSafeTimedSerializer(
+                current_app.config["SECRET_KEY"], salt=token_type
             )
-            token = serializer.dumps({"project_id": self.id}).decode("utf-8")
+            token = serializer.dumps([self.id])
         else:
-            serializer = URLSafeSerializer(current_app.config["SECRET_KEY"])
-            token = serializer.dumps({"project_id": self.id})
+            serializer = URLSafeSerializer(
+                current_app.config["SECRET_KEY"] + self.password, salt=token_type
+            )
+            token = serializer.dumps([self.id])
+
         return token
 
     @staticmethod
-    def verify_token(token, token_type="timed_token"):
+    def verify_token(token, token_type="auth", project_id=None, max_age=3600):
         """Return the project id associated to the provided token,
         None if the provided token is expired or not valid.
 
         :param token: Serialized TimedJsonWebToken
+        :param token_type: Either "auth" for authentication (invalidated when project code changed),
+                        or "reset" for password reset (invalidated after expiration)
+        :param project_id: Project ID. Used for token_type "auth" to use the password as serializer
+                        secret key.
+        :param max_age: Token expiration time (in seconds). Only used with token_type "reset"
         """
-        if token_type == "timed_token":
-            serializer = TimedJSONWebSignatureSerializer(
-                current_app.config["SECRET_KEY"]
+        loads_kwargs = {}
+        if token_type == "reset":
+            serializer = URLSafeTimedSerializer(
+                current_app.config["SECRET_KEY"], salt=token_type
             )
+            loads_kwargs["max_age"] = max_age
         else:
-            serializer = URLSafeSerializer(current_app.config["SECRET_KEY"])
+            project = Project.query.get(project_id) if project_id is not None else None
+            password = project.password if project is not None else ""
+            serializer = URLSafeSerializer(
+                current_app.config["SECRET_KEY"] + password, salt=token_type
+            )
         try:
-            data = serializer.loads(token)
+            data = serializer.loads(token, **loads_kwargs)
         except SignatureExpired:
             return None
         except BadSignature:
             return None
-        return data["project_id"]
+
+        data_project = data[0] if isinstance(data, list) else None
+        return (
+            data_project if project_id is None or data_project == project_id else None
+        )
 
     def __str__(self):
         return self.name
diff --git a/ihatemoney/templates/invitation_mail.en.j2 b/ihatemoney/templates/invitation_mail.en.j2
index 79fcc427..2b3157b1 100644
--- a/ihatemoney/templates/invitation_mail.en.j2
+++ b/ihatemoney/templates/invitation_mail.en.j2
@@ -4,7 +4,7 @@ Someone using the email address {{ g.project.contact_email }} invited you to sha
 
 It's as simple as saying what did you pay for, for whom, and how much did it cost you, we are caring about the rest.
 
-You can log in using this link: {{ url_for(".authenticate", _external=True, token=g.project.generate_token()) }}.
+You can log in using this link: {{ url_for(".authenticate", _external=True, project_id=g.project.id, token=g.project.generate_token()) }}.
 
 Once logged-in, you can use the following link which is easier to remember: {{ url_for(".list_bills", _external=True) }}
 If your cookie gets deleted or if you log out, you will need to log back in using the first link.
diff --git a/ihatemoney/templates/invitation_mail.fr.j2 b/ihatemoney/templates/invitation_mail.fr.j2
index e57d7035..d095cfdb 100644
--- a/ihatemoney/templates/invitation_mail.fr.j2
+++ b/ihatemoney/templates/invitation_mail.fr.j2
@@ -4,7 +4,7 @@ Quelqu'un dont l'adresse email est {{ g.project.contact_email }} vous a invité
 
 Il suffit de renseigner qui a payé pour quoi, pour qui, combien ça a coûté, et on s’occupe du reste.
 
-Vous pouvez vous connecter grâce à ce lien : {{ url_for(".authenticate", _external=True, token=g.project.generate_token()) }}.
+Vous pouvez vous connecter grâce à ce lien : {{ url_for(".authenticate", _external=True, project_id=g.project.id, token=g.project.generate_token()) }}.
 
 Une fois connecté, vous pourrez utiliser le lien suivant qui est plus facile à mémoriser : {{ url_for(".list_bills", _external=True) }}
 Si vous êtes déconnecté volontairement ou non, vous devrez utiliser à nouveau le premier lien.
diff --git a/ihatemoney/templates/password_reminder.en.j2 b/ihatemoney/templates/password_reminder.en.j2
index c6543546..845ff790 100644
--- a/ihatemoney/templates/password_reminder.en.j2
+++ b/ihatemoney/templates/password_reminder.en.j2
@@ -1,7 +1,7 @@
 Hi,
 
 You requested to reset the password of the following project: "{{ project.name }}".
-You can reset it here: {{ url_for(".reset_password", _external=True, token=project.generate_token(expiration=3600)) }}.
+You can reset it here: {{ url_for(".reset_password", _external=True, token=project.generate_token(token_type="reset")) }}.
 This link is only valid for one hour.
 
 Hope this helps,
diff --git a/ihatemoney/templates/password_reminder.fr.j2 b/ihatemoney/templates/password_reminder.fr.j2
index 17c52c4d..4603a963 100644
--- a/ihatemoney/templates/password_reminder.fr.j2
+++ b/ihatemoney/templates/password_reminder.fr.j2
@@ -1,7 +1,7 @@
 Salut,
 
 Vous avez demandé à réinitialiser le mot de passe du projet suivant : "{{ project.name }}".
-Vous pouvez le réinitialiser ici : {{ url_for(".reset_password", _external=True, token=project.generate_token(expiration=3600)) }}.
+Vous pouvez le réinitialiser ici : {{ url_for(".reset_password", _external=True, token=project.generate_token(token_type="reset")) }}.
 Ce lien est seulement valide pendant 1 heure.
 
 Faites-en bon usage !
diff --git a/ihatemoney/templates/send_invites.html b/ihatemoney/templates/send_invites.html
index 53492c85..8b73b175 100644
--- a/ihatemoney/templates/send_invites.html
+++ b/ihatemoney/templates/send_invites.html
@@ -21,8 +21,8 @@
             </td>
             <td>
                 {{ _("You can directly share the following link via your prefered medium") }}</br>
-                <a href="{{ url_for(".authenticate", _external=True, token=g.project.generate_token()) }}">
-                    {{ url_for(".authenticate", _external=True, token=g.project.generate_token()) }}
+                <a href="{{ url_for(".authenticate", _external=True, project_id=g.project.id, token=g.project.generate_token()) }}">
+                    {{ url_for(".authenticate", _external=True, project_id=g.project.id, token=g.project.generate_token()) }}
                 </a>
             </td>
         </tr>
diff --git a/ihatemoney/tests/api_test.py b/ihatemoney/tests/api_test.py
index 41f5ab2d..83d5aa2a 100644
--- a/ihatemoney/tests/api_test.py
+++ b/ihatemoney/tests/api_test.py
@@ -213,7 +213,9 @@ class APITestCase(IhatemoneyTestCase):
             "/api/projects/raclette/token", headers=self.get_auth("raclette")
         )
         decoded_resp = json.loads(resp.data.decode("utf-8"))
-        resp = self.client.get("/authenticate?token={}".format(decoded_resp["token"]))
+        resp = self.client.get(
+            f"/authenticate?token={decoded_resp['token']}&project_id=raclette"
+        )
         # Test that we are redirected.
         self.assertEqual(302, resp.status_code)
 
diff --git a/ihatemoney/tests/budget_test.py b/ihatemoney/tests/budget_test.py
index 75a2dc35..af33197a 100644
--- a/ihatemoney/tests/budget_test.py
+++ b/ihatemoney/tests/budget_test.py
@@ -4,6 +4,7 @@ import json
 import re
 from time import sleep
 import unittest
+from urllib.parse import parse_qs, urlencode, urlparse, urlunparse
 
 from flask import session
 import pytest
@@ -11,6 +12,7 @@ from werkzeug.security import check_password_hash, generate_password_hash
 
 from ihatemoney import models
 from ihatemoney.currency_convertor import CurrencyConverter
+from ihatemoney.tests.common.help_functions import extract_link
 from ihatemoney.tests.common.ihatemoney_testcase import IhatemoneyTestCase
 from ihatemoney.versioning import LoggingMode
 
@@ -87,11 +89,52 @@ class BudgetTestCase(IhatemoneyTestCase):
         )
         # Test empty and invalid tokens
         self.client.get("/exit")
+        # Use another project_id
+        parsed_url = urlparse(url)
+        query = parse_qs(parsed_url.query)
+        query["project_id"] = "invalid"
+        resp = self.client.get(
+            urlunparse(parsed_url._replace(query=urlencode(query, doseq=True)))
+        )
+        assert "You either provided a bad token" in resp.data.decode("utf-8")
+
         resp = self.client.get("/authenticate")
         self.assertIn("You either provided a bad token", resp.data.decode("utf-8"))
         resp = self.client.get("/authenticate?token=token")
         self.assertIn("You either provided a bad token", resp.data.decode("utf-8"))
 
+    def test_invite_code_invalidation(self):
+        """Test that invitation link expire after code change"""
+        self.login("raclette")
+        self.post_project("raclette")
+        response = self.client.get("/raclette/invite").data.decode("utf-8")
+        link = extract_link(response, "share the following link")
+
+        self.client.get("/exit")
+        response = self.client.get(link)
+        # Link is valid
+        assert response.status_code == 302
+
+        # Change password to invalidate token
+        # Other data are required, but useless for the test
+        response = self.client.post(
+            "/raclette/edit",
+            data={
+                "name": "raclette",
+                "contact_email": "zorglub@notmyidea.org",
+                "password": "didoudida",
+                "default_currency": "XXX",
+            },
+            follow_redirects=True,
+        )
+        assert response.status_code == 200
+        assert "alert-danger" not in response.data.decode("utf-8")
+
+        self.client.get("/exit")
+        response = self.client.get(link, follow_redirects=True)
+        # Link is invalid
+        self.assertIn("You either provided a bad token", response.data.decode("utf-8"))
+
     def test_password_reminder(self):
         # test that it is possible to have an email containing the password of a
         # project in case people forget it (and it happens!)
diff --git a/ihatemoney/tests/common/help_functions.py b/ihatemoney/tests/common/help_functions.py
index e9c4dcd1..5a401059 100644
--- a/ihatemoney/tests/common/help_functions.py
+++ b/ihatemoney/tests/common/help_functions.py
@@ -1,5 +1,16 @@
+from markupsafe import Markup
+
+
 def em_surround(string, regex_escape=False):
     if regex_escape:
         return r'<em class="font-italic">%s<\/em>' % string
     else:
         return '<em class="font-italic">%s</em>' % string
+
+
+def extract_link(data, start_prefix):
+    base_index = data.find(start_prefix)
+    start = data.find('href="', base_index) + 6
+    end = data.find('">', base_index)
+    link = Markup(data[start:end]).unescape()
+    return link
diff --git a/ihatemoney/web.py b/ihatemoney/web.py
index 712d2b0e..5af15e08 100644
--- a/ihatemoney/web.py
+++ b/ihatemoney/web.py
@@ -199,15 +199,21 @@ def admin():
 def authenticate(project_id=None):
     """Authentication form"""
     form = AuthenticationForm()
+
+    if not form.id.data and request.args.get("project_id"):
+        form.id.data = request.args["project_id"]
+    project_id = form.id.data
     # Try to get project_id from token first
     token = request.args.get("token")
     if token:
-        project_id = Project.verify_token(token, token_type="non_timed_token")
-        token_auth = True
+        verified_project_id = Project.verify_token(
+            token, token_type="auth", project_id=project_id
+        )
+        if verified_project_id == project_id:
+            token_auth = True
+        else:
+            project_id = None
     else:
-        if not form.id.data and request.args.get("project_id"):
-            form.id.data = request.args["project_id"]
-        project_id = form.id.data
         token_auth = False
     if project_id is None:
         # User doesn't provide project identifier or a valid token
@@ -381,7 +387,7 @@ def reset_password():
         return render_template(
             "reset_password.html", form=form, error=_("No token provided")
         )
-    project_id = Project.verify_token(token)
+    project_id = Project.verify_token(token, token_type="reset")
     if not project_id:
         return render_template(
             "reset_password.html", form=form, error=_("Invalid token")