diff --git a/nixos/modules/virtualisation/nixos-containers.nix b/nixos/modules/virtualisation/nixos-containers.nix
index d4fa707b2dd5..5db3a336f85d 100644
--- a/nixos/modules/virtualisation/nixos-containers.nix
+++ b/nixos/modules/virtualisation/nixos-containers.nix
@@ -509,6 +509,12 @@ in
                                 for details).
                               '';
                             }
+                            {
+                              assertion = !lib.strings.hasInfix "_" name;
+                              message = ''
+                                Names containing underscores are not allowed in nixos-containers. Please rename the container '${name}'
+                              '';
+                            }
                           ];
                         };
                       };