diff --git a/services/matrix/synapse.nix b/services/matrix/synapse.nix
index d06bafa..f03286e 100644
--- a/services/matrix/synapse.nix
+++ b/services/matrix/synapse.nix
@@ -47,6 +47,8 @@ in {
         "#general:pvv.ntnu.no"
       ];
 
+      allow_public_rooms_over_federation = true;
+
       max_upload_size = "150M";
 
       enable_metrics = true;