diff --git a/lix/libcmd/command.cc b/lix/libcmd/command.cc
index b6a6e064b..4dd5fdb67 100644
--- a/lix/libcmd/command.cc
+++ b/lix/libcmd/command.cc
@@ -28,12 +28,6 @@ nix::Commands RegisterCommand::getCommandsFor(const std::vector<std::string> & p
     return res;
 }
 
-nlohmann::json NixMultiCommand::toJSON()
-{
-    // FIXME: use Command::toJSON() as well.
-    return MultiCommand::toJSON();
-}
-
 StoreCommand::StoreCommand()
 {
 }
diff --git a/lix/libcmd/command.hh b/lix/libcmd/command.hh
index 27f242f54..29b47cbac 100644
--- a/lix/libcmd/command.hh
+++ b/lix/libcmd/command.hh
@@ -26,11 +26,6 @@ static constexpr Command::Category catNixInstallation = 102;
 
 static constexpr auto installablesCategory = "Options that change the interpretation of [installables](@docroot@/command-ref/new-cli/nix.md#installables)";
 
-struct NixMultiCommand : virtual MultiCommand, virtual Command
-{
-    nlohmann::json toJSON() override;
-};
-
 // For the overloaded run methods
 #pragma GCC diagnostic ignored "-Woverloaded-virtual"
 
diff --git a/lix/libutil/args.cc b/lix/libutil/args.cc
index 92b24df20..ee9fa6b72 100644
--- a/lix/libutil/args.cc
+++ b/lix/libutil/args.cc
@@ -440,6 +440,8 @@ bool MultiCommand::processArgs(const Strings & args, bool finish)
 
 nlohmann::json MultiCommand::toJSON()
 {
+    // FIXME: use Command::toJSON() as well.
+
     auto cmds = nlohmann::json::object();
 
     for (auto & [name, commandFun] : commands) {
diff --git a/lix/libutil/args.hh b/lix/libutil/args.hh
index dcec2ccbc..681d9c426 100644
--- a/lix/libutil/args.hh
+++ b/lix/libutil/args.hh
@@ -343,7 +343,7 @@ typedef std::map<std::string, std::function<ref<Command>()>> Commands;
  * An argument parser that supports multiple subcommands,
  * i.e. ‘<command> <subcommand>’.
  */
-class MultiCommand : virtual public Args
+class MultiCommand : public Command
 {
 public:
     Commands commands;
diff --git a/lix/nix/config.cc b/lix/nix/config.cc
index 67fcd9f4f..5f744e9ec 100644
--- a/lix/nix/config.cc
+++ b/lix/nix/config.cc
@@ -7,7 +7,7 @@
 
 using namespace nix;
 
-struct CmdConfig : virtual NixMultiCommand
+struct CmdConfig : virtual MultiCommand
 {
     CmdConfig() : MultiCommand(RegisterCommand::getCommandsFor({"config"}))
     { }
diff --git a/lix/nix/derivation.cc b/lix/nix/derivation.cc
index 2d1717f0c..8df5e64c6 100644
--- a/lix/nix/derivation.cc
+++ b/lix/nix/derivation.cc
@@ -2,7 +2,7 @@
 
 using namespace nix;
 
-struct CmdDerivation : virtual NixMultiCommand
+struct CmdDerivation : virtual MultiCommand
 {
     CmdDerivation() : MultiCommand(RegisterCommand::getCommandsFor({"derivation"}))
     { }
diff --git a/lix/nix/flake.cc b/lix/nix/flake.cc
index 61acbeacc..47a2573c0 100644
--- a/lix/nix/flake.cc
+++ b/lix/nix/flake.cc
@@ -1464,7 +1464,7 @@ struct CmdFlakePrefetch : FlakeCommand, MixJSON
     }
 };
 
-struct CmdFlake : NixMultiCommand
+struct CmdFlake : MultiCommand
 {
     CmdFlake()
         : MultiCommand({
diff --git a/lix/nix/hash.cc b/lix/nix/hash.cc
index 94bbe86ac..fbabe0345 100644
--- a/lix/nix/hash.cc
+++ b/lix/nix/hash.cc
@@ -124,7 +124,7 @@ struct CmdToBase : Command
     }
 };
 
-struct CmdHash : NixMultiCommand
+struct CmdHash : MultiCommand
 {
     CmdHash()
         : MultiCommand({
diff --git a/lix/nix/main.cc b/lix/nix/main.cc
index b464808fc..826b4f238 100644
--- a/lix/nix/main.cc
+++ b/lix/nix/main.cc
@@ -214,6 +214,11 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs, virtual RootArgs
           ;
     }
 
+    void run() override
+    {
+        command->second->run();
+    }
+
     // Plugins may add new subcommands.
     void pluginsInited() override
     {
@@ -528,7 +533,7 @@ void mainWrapped(int argc, char * * argv)
     if (args.command->second->forceImpureByDefault()) {
         evalSettings.pureEval.setDefault(false);
     }
-    args.command->second->run();
+    args.run();
 }
 
 }
diff --git a/lix/nix/nar.cc b/lix/nix/nar.cc
index 5954c680f..2061b0f1f 100644
--- a/lix/nix/nar.cc
+++ b/lix/nix/nar.cc
@@ -2,7 +2,7 @@
 
 using namespace nix;
 
-struct CmdNar : NixMultiCommand
+struct CmdNar : MultiCommand
 {
     CmdNar() : MultiCommand(RegisterCommand::getCommandsFor({"nar"}))
     { }
diff --git a/lix/nix/profile.cc b/lix/nix/profile.cc
index 9878ca514..d5d20ce71 100644
--- a/lix/nix/profile.cc
+++ b/lix/nix/profile.cc
@@ -601,7 +601,7 @@ struct CmdProfileWipeHistory : virtual StoreCommand, MixDefaultProfile, MixDryRu
     }
 };
 
-struct CmdProfile : NixMultiCommand
+struct CmdProfile : MultiCommand
 {
     CmdProfile()
         : MultiCommand({
diff --git a/lix/nix/realisation.cc b/lix/nix/realisation.cc
index 9ed910f45..80308e99f 100644
--- a/lix/nix/realisation.cc
+++ b/lix/nix/realisation.cc
@@ -5,7 +5,7 @@
 
 using namespace nix;
 
-struct CmdRealisation : virtual NixMultiCommand
+struct CmdRealisation : virtual MultiCommand
 {
     CmdRealisation() : MultiCommand(RegisterCommand::getCommandsFor({"realisation"}))
     { }
diff --git a/lix/nix/registry.cc b/lix/nix/registry.cc
index d0e9a8f2f..5bdba362b 100644
--- a/lix/nix/registry.cc
+++ b/lix/nix/registry.cc
@@ -204,7 +204,7 @@ struct CmdRegistryPin : RegistryCommand, EvalCommand
     }
 };
 
-struct CmdRegistry : virtual NixMultiCommand
+struct CmdRegistry : virtual MultiCommand
 {
     CmdRegistry()
         : MultiCommand({
diff --git a/lix/nix/sigs.cc b/lix/nix/sigs.cc
index d84b0e10a..9a63e19cf 100644
--- a/lix/nix/sigs.cc
+++ b/lix/nix/sigs.cc
@@ -199,7 +199,7 @@ struct CmdKeyConvertSecretToPublic : Command
     }
 };
 
-struct CmdKey : NixMultiCommand
+struct CmdKey : MultiCommand
 {
     CmdKey()
         : MultiCommand({
diff --git a/lix/nix/store.cc b/lix/nix/store.cc
index 98ff26870..00f980088 100644
--- a/lix/nix/store.cc
+++ b/lix/nix/store.cc
@@ -2,7 +2,7 @@
 
 using namespace nix;
 
-struct CmdStore : virtual NixMultiCommand
+struct CmdStore : virtual MultiCommand
 {
     CmdStore() : MultiCommand(RegisterCommand::getCommandsFor({"store"}))
     { }