diff --git a/ihatemoney/run.py b/ihatemoney/run.py
index c8fc5b25..7beedc78 100644
--- a/ihatemoney/run.py
+++ b/ihatemoney/run.py
@@ -19,6 +19,7 @@ from ihatemoney.models import db
 from ihatemoney.utils import (
     IhmJSONEncoder,
     PrefixedWSGI,
+    RegexConverter,
     em_surround,
     locale_from_iso,
     localize_list,
@@ -126,6 +127,8 @@ def create_app(
         instance_relative_config=instance_relative_config,
     )
 
+    app.url_map.converters["regex"] = RegexConverter
+
     # If a configuration object is passed, use it. Otherwise try to find one.
     load_configuration(app, configuration)
     app.wsgi_app = PrefixedWSGI(app)
diff --git a/ihatemoney/templates/invitation_mail.en.j2 b/ihatemoney/templates/invitation_mail.en.j2
index 2b3157b1..8523eb6b 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, project_id=g.project.id, token=g.project.generate_token()) }}.
+You can log in using this link: {{ url_for(".invitation", _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 d095cfdb..828c3338 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, project_id=g.project.id, token=g.project.generate_token()) }}.
+Vous pouvez vous connecter grâce à ce lien : {{ url_for(".invitation", _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/send_invites.html b/ihatemoney/templates/send_invites.html
index 8b73b175..1a952f2b 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, 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 href="{{ url_for(".invitation", _external=True, project_id=g.project.id, token=g.project.generate_token()) }}">
+                    {{ url_for(".invitation", _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 83d5aa2a..63956d6b 100644
--- a/ihatemoney/tests/api_test.py
+++ b/ihatemoney/tests/api_test.py
@@ -213,9 +213,7 @@ 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(
-            f"/authenticate?token={decoded_resp['token']}&project_id=raclette"
-        )
+        resp = self.client.get(f"/raclette/{decoded_resp['token']}")
         # 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 af33197a..15f9a671 100644
--- a/ihatemoney/tests/budget_test.py
+++ b/ihatemoney/tests/budget_test.py
@@ -4,7 +4,7 @@ import json
 import re
 from time import sleep
 import unittest
-from urllib.parse import parse_qs, urlencode, urlparse, urlunparse
+from urllib.parse import urlparse, urlunparse
 
 from flask import session
 import pytest
@@ -91,16 +91,20 @@ class BudgetTestCase(IhatemoneyTestCase):
         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)))
+            urlunparse(
+                parsed_url._replace(
+                    path=parsed_url.path.replace("raclette/", "invalid_project/")
+                )
+            ),
+            follow_redirects=True,
         )
-        assert "You either provided a bad token" in resp.data.decode("utf-8")
+        assert "Create a new project" 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")
+        # A token MUST have a point between payload and signature
+        resp = self.client.get("/raclette/token.invalid", follow_redirects=True)
         self.assertIn("You either provided a bad token", resp.data.decode("utf-8"))
 
     def test_invite_code_invalidation(self):
diff --git a/ihatemoney/utils.py b/ihatemoney/utils.py
index 66f5b6a4..cc1f4911 100644
--- a/ihatemoney/utils.py
+++ b/ihatemoney/utils.py
@@ -16,7 +16,7 @@ from flask import current_app, escape, redirect, render_template
 from flask_babel import get_locale, lazy_gettext as _
 import jinja2
 from markupsafe import Markup
-from werkzeug.routing import HTTPException, RoutingException
+from werkzeug.routing import BaseConverter, HTTPException, RoutingException
 
 
 def slugify(value):
@@ -416,3 +416,10 @@ def format_form_errors(form, prefix):
         errors = f"<ul><li>{error_list}</li></ul>"
         # I18N: Form error with a list of errors
         return Markup(_("{prefix}:<br />{errors}").format(prefix=prefix, errors=errors))
+
+
+# Taken from https://stackoverflow.com/a/5872904
+class RegexConverter(BaseConverter):
+    def __init__(self, url_map, *items):
+        super(RegexConverter, self).__init__(url_map)
+        self.regex = items[0]
diff --git a/ihatemoney/web.py b/ihatemoney/web.py
index 5af15e08..dd743d6a 100644
--- a/ihatemoney/web.py
+++ b/ihatemoney/web.py
@@ -143,7 +143,8 @@ def pull_project(endpoint, values):
             raise Redirect303(url_for(".create_project", project_id=project_id))
 
         is_admin = session.get("is_admin")
-        if session.get(project.id) or is_admin:
+        is_invitation = endpoint == "main.invitation"
+        if session.get(project.id) or is_admin or is_invitation:
             # add project into kwargs and call the original function
             g.project = project
         else:
@@ -195,6 +196,32 @@ def admin():
     )
 
 
+# To avoid matching other endpoint with a malformed token,
+# ensure that it has a point in the middle, since it's the
+# default separator between payload and signature.
+@main.route("/<project_id>/<regex('.+\\..+'):token>", methods=["GET"])
+def invitation(token):
+    project_id = g.project.id
+    verified_project_id = Project.verify_token(
+        token, token_type="auth", project_id=project_id
+    )
+    if verified_project_id != project_id:
+        # User doesn't provide project identifier or a valid token
+        # redirect to authenticate form
+        return redirect(url_for(".authenticate", project_id=project_id, bad_token=1))
+
+    # maintain a list of visited projects
+    if "projects" not in session:
+        session["projects"] = []
+    # add the project on the top of the list
+    session["projects"].insert(0, (project_id, g.project.name))
+    session[project_id] = True
+    # Set session to permanent to make language choice persist
+    session.permanent = True
+    session.update()
+    return redirect(url_for(".list_bills"))
+
+
 @main.route("/authenticate", methods=["GET", "POST"])
 def authenticate(project_id=None):
     """Authentication form"""
@@ -203,19 +230,8 @@ def authenticate(project_id=None):
     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:
-        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:
-        token_auth = False
-    if project_id is None:
+
+    if project_id is None or request.args.get("bad_token") is not None:
         # User doesn't provide project identifier or a valid token
         # return to authenticate form
         msg = _("You either provided a bad token or no project identifier.")
@@ -235,13 +251,9 @@ def authenticate(project_id=None):
         setattr(g, "project", project)
         return redirect(url_for(".list_bills"))
 
-    # else do form authentication or token authentication
+    # else do form authentication authentication
     is_post_auth = request.method == "POST" and form.validate()
-    if (
-        is_post_auth
-        and check_password_hash(project.password, form.password.data)
-        or token_auth
-    ):
+    if is_post_auth and check_password_hash(project.password, form.password.data):
         # maintain a list of visited projects
         if "projects" not in session:
             session["projects"] = []