diff --git a/nix/sources.json b/nix/sources.json
index fd6eaed..2448d4a 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -1,6 +1,6 @@
 {
     "haccmap": {
-        "ref": "master",
+        "branch": "master",
         "repo": "https://gitlab.infra4future.de/hacc/haccspace-rc3-map",
         "rev": "3b99ee7e5bb2f27044784d03572da77d39cb2427",
         "type": "git"
@@ -89,7 +89,7 @@
         "type": "git"
     },
     "workadventure": {
-        "ref": "master",
+        "branch": "master",
         "repo": "https://stuebinm.eu/git/workadventure-nix",
         "rev": "cbe9196fba75be98569d7504e7c1d091bcbf053e",
         "type": "git"