diff --git a/nixos/modules/programs/tsm-client.nix b/nixos/modules/programs/tsm-client.nix
index 03dc50eea801..45d436221ee3 100644
--- a/nixos/modules/programs/tsm-client.nix
+++ b/nixos/modules/programs/tsm-client.nix
@@ -1,4 +1,5 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:  # XXX migration code for freeform settings: `options` can be removed in 2025
+let optionsGlobal = options; in
 
 let
 
@@ -95,6 +96,19 @@ let
     };
     config.commmethod = mkDefault "v6tcpip";  # uses v4 or v6, based on dns lookup result
     config.passwordaccess = if config.genPasswd then "generate" else "prompt";
+    # XXX migration code for freeform settings, these can be removed in 2025:
+    options.warnings = optionsGlobal.warnings;
+    options.assertions = optionsGlobal.assertions;
+    imports = let inherit (lib.modules) mkRemovedOptionModule mkRenamedOptionModule; in [
+      (mkRemovedOptionModule [ "extraConfig" ] "Please just add options directly to the server attribute set, cf. the description of `programs.tsmClient.servers`.")
+      (mkRemovedOptionModule [ "text" ] "Please just add options directly to the server attribute set, cf. the description of `programs.tsmClient.servers`.")
+      (mkRenamedOptionModule [ "name" ] [ "servername" ])
+      (mkRenamedOptionModule [ "server" ] [ "tcpserveraddress" ])
+      (mkRenamedOptionModule [ "port" ] [ "tcpport" ])
+      (mkRenamedOptionModule [ "node" ] [ "nodename" ])
+      (mkRenamedOptionModule [ "passwdDir" ] [ "passworddir" ])
+      (mkRenamedOptionModule [ "includeExclude" ] [ "inclexcl" ])
+    ];
   };
 
   options.programs.tsmClient = {
@@ -209,7 +223,9 @@ let
         contain duplicate names
         (note that setting names are case insensitive).
       '';
-    }) cfg.servers);
+    }) cfg.servers)
+    # XXX migration code for freeform settings, this can be removed in 2025:
+    ++ (enrichMigrationInfos "assertions" (addText: { assertion, message }: { inherit assertion; message = addText message; }));
 
   makeDsmSysLines = key: value:
     # Turn a key-value pair from the server options attrset
@@ -228,7 +244,12 @@ let
   makeDsmSysStanza = {servername, ... }@serverCfg:
     let
       # drop special values that should not go into server config block
-      attrs = removeAttrs serverCfg [ "servername" "genPasswd" ];
+      attrs = removeAttrs serverCfg [ "servername" "genPasswd"
+        # XXX migration code for freeform settings, these can be removed in 2025:
+        "assertions" "warnings"
+        "extraConfig" "text"
+        "name" "server" "port" "node" "passwdDir" "includeExclude"
+      ];
     in
       ''
         servername  ${servername}
@@ -246,6 +267,13 @@ let
     ${concatLines (map makeDsmSysStanza (attrValues cfg.servers))}
   '';
 
+  # XXX migration code for freeform settings, this can be removed in 2025:
+  enrichMigrationInfos = what: how: concatLists (
+    mapAttrsToList
+    (name: serverCfg: map (how (text: "In `programs.tsmClient.servers.${name}`: ${text}")) serverCfg."${what}")
+    cfg.servers
+  );
+
 in
 
 {
@@ -260,6 +288,8 @@ in
       dsmSysApi = dsmSysCli;
     };
     environment.systemPackages = [ cfg.wrappedPackage ];
+    # XXX migration code for freeform settings, this can be removed in 2025:
+    warnings = enrichMigrationInfos "warnings" (addText: addText);
   };
 
   meta.maintainers = [ lib.maintainers.yarny ];