diff --git a/src/nix/build.cc b/src/nix/build.cc
index 35603f557..812464d75 100644
--- a/src/nix/build.cc
+++ b/src/nix/build.cc
@@ -43,4 +43,4 @@ struct CmdBuild : StoreCommand, MixDryRun, MixInstallables
     }
 };
 
-static RegisterCommand r1(make_ref<Command, CmdBuild>());
+static RegisterCommand r1(make_ref<CmdBuild>());
diff --git a/src/nix/command.cc b/src/nix/command.cc
index 698863349..9c80f4309 100644
--- a/src/nix/command.cc
+++ b/src/nix/command.cc
@@ -59,7 +59,7 @@ bool MultiCommand::processArgs(const Strings & args, bool finish)
 
 void StoreCommand::run()
 {
-    run(openStore(reserveSpace));
+    run(openStore());
 }
 
 }
diff --git a/src/nix/hash.cc b/src/nix/hash.cc
index 452aa4ef6..5dd891e8a 100644
--- a/src/nix/hash.cc
+++ b/src/nix/hash.cc
@@ -45,8 +45,8 @@ struct CmdHash : Command
     }
 };
 
-static RegisterCommand r1(make_ref<Command, CmdHash>(CmdHash::mFile));
-static RegisterCommand r2(make_ref<Command, CmdHash>(CmdHash::mPath));
+static RegisterCommand r1(make_ref<CmdHash>(CmdHash::mFile));
+static RegisterCommand r2(make_ref<CmdHash>(CmdHash::mPath));
 
 struct CmdToBase : Command
 {
@@ -82,8 +82,8 @@ struct CmdToBase : Command
     }
 };
 
-static RegisterCommand r3(make_ref<Command, CmdToBase>(false));
-static RegisterCommand r4(make_ref<Command, CmdToBase>(true));
+static RegisterCommand r3(make_ref<CmdToBase>(false));
+static RegisterCommand r4(make_ref<CmdToBase>(true));
 
 /* Legacy nix-hash command. */
 static int compatNixHash(int argc, char * * argv)