diff --git a/pyproject.toml b/pyproject.toml
index 8ae577c..e6efc18 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,7 +5,7 @@ requires-python = ">=3.12"
 dependencies = [
   # from setup.py
   "connexion[swagger-ui] ~= 2.14",
-  "Flask ~= 1.1",
+  "Flask ~=3.1",
   "flask-healthz ~= 0.0.3",
   "Flask-Migrate ~= 2.7",
   "Flask-SQLAlchemy ~= 2.5",