diff --git a/ihatemoney/tests/budget_test.py b/ihatemoney/tests/budget_test.py
index 1b51554a..6110fabd 100644
--- a/ihatemoney/tests/budget_test.py
+++ b/ihatemoney/tests/budget_test.py
@@ -1665,6 +1665,26 @@ class BudgetTestCase(IhatemoneyTestCase):
         # No bills, the previous one was not added
         self.assertIn("No bills", resp.data.decode("utf-8"))
 
+    def test_session_projects_migration_to_list(self):
+        """In https://github.com/spiral-project/ihatemoney/pull/1082, session["projects"]
+        was migrated from a list to a dict. We need to handle this.
+        """
+        self.post_project("raclette")
+        self.client.get("/exit")
+
+        with self.client as c:
+            c.post("/authenticate", data={"id": "raclette", "password": "raclette"})
+            self.assertTrue(session["raclette"])
+            # New behavior
+            self.assertIsInstance(session["projects"], dict)
+            # Now, go back to the past
+            with c.session_transaction() as sess:
+                sess["projects"] = [("raclette", "raclette")]
+            # It should convert entry to dict
+            c.get("/")
+            self.assertIsInstance(session["projects"], dict)
+            self.assertIn("raclette", session["projects"])
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/ihatemoney/web.py b/ihatemoney/web.py
index 9e034029..19135a0c 100644
--- a/ihatemoney/web.py
+++ b/ihatemoney/web.py
@@ -112,6 +112,13 @@ def add_project_id(endpoint, values):
         values["project_id"] = g.project.id
 
 
+@main.url_value_preprocessor
+def migrate_session(endpoint, values):
+    if "projects" in session and isinstance(session["projects"], list):
+        # Migrate https://github.com/spiral-project/ihatemoney/pull/1082
+        session["projects"] = {id: name for (id, name) in session["projects"]}
+
+
 @main.url_value_preprocessor
 def set_show_admin_dashboard_link(endpoint, values):
     """Sets the "show_admin_dashboard_link" variable application wide