diff --git a/nixbld-etc-nixos/configuration.nix b/nixbld-etc-nixos/configuration.nix
index c2f89fb6..69515f8d 100644
--- a/nixbld-etc-nixos/configuration.nix
+++ b/nixbld-etc-nixos/configuration.nix
@@ -718,9 +718,5 @@ in
   };
   services.jitsi-videobridge.openFirewall = true;
 
-  # This value determines the NixOS release with which your system is to be
-  # compatible, in order to avoid breaking some software such as database
-  # servers. You should change this only after NixOS release notes say you
-  # should.
-  system.stateVersion = "18.09"; # Did you read the comment?
+  system.stateVersion = "21.05";
 }