diff --git a/myice/webapi.py b/myice/webapi.py
index 97706da..6b44a64 100644
--- a/myice/webapi.py
+++ b/myice/webapi.py
@@ -10,9 +10,9 @@ from . import myice
 
 # OIDC Configuration
 CLIENT_ID = os.environ.get("CLIENT_ID", "8ea04fbb-4237-4b1d-a895-0b3575a3af3f")
-CLIENT_SECRET = os.environ.get(
-    "CLIENT_SECRET", "REDACTED_CLIENT_SECRET"
-)
+CLIENT_SECRET = os.environ.get("CLIENT_SECRET")
+if not CLIENT_SECRET:
+    raise RuntimeError("CLIENT_SECRET environment variable must be set")
 REDIRECT_URI = os.environ.get("REDIRECT_URI", "http://localhost:8000/callback")
 AUTHORIZATION_ENDPOINT = "https://login.infomaniak.com/authorize"
 TOKEN_ENDPOINT = "https://login.infomaniak.com/token"