diff --git a/pyproject.toml b/pyproject.toml
index d697e30..5bbac24 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,7 +19,7 @@ dependencies = [
     "psycopg[binary]>=3.2,<4",
     "tzdata>=2024.2",
     "pyjwt>=2.9,<3",
-    "argon2-cffi>=23.1,<24",
+    "argon2-cffi>=23.1,<26",
     "redis>=5.0,<6",
     # Runtime HTTP client: main.py + the webhook delivery worker use httpx.AsyncClient. It must be a
     # runtime dependency, not dev-only, or the --no-dev production image fails to import at startup.