diff --git a/repos.json.lock b/repos.json.lock
index 5b9e600de..8b8a190f4 100644
--- a/repos.json.lock
+++ b/repos.json.lock
@@ -11,8 +11,8 @@
             "url": "https://gricad-gitlab.univ-grenoble-alpes.fr/Projets-INFO4/18-19/19/code"
         },
         "arc": {
-            "rev": "7fb8ed99b592766187db23534637f6b72346b8b2",
-            "sha256": "0fvw9kwp6dv17l1b333kwimkpb8k1vpcgxi2bypp82qzccaazzds",
+            "rev": "4b8da901e1d8a740aa91c371fcc203c06e5e997a",
+            "sha256": "0is9i3bn741w8ly3mzln8af7b4ad5q50gmfm0rq0477yxc6df8sq",
             "url": "https://github.com/arcnmx/nixexprs"
         },
         "bb010g": {