diff --git a/lib/build-vms.nix b/lib/build-vms.nix
index 913d5276db2c..f151060344e8 100644
--- a/lib/build-vms.nix
+++ b/lib/build-vms.nix
@@ -76,7 +76,7 @@ rec {
                          "${config.networking.hostName}\n"));
                   
                   virtualisation.qemu.options =
-                    lib.flip lib.concatMapStrings interfacesNumbered
+                    lib.flip map interfacesNumbered
                       ({ first, second }: qemuNICFlags second first m.second);
                 };
             }
diff --git a/lib/qemu-flags.nix b/lib/qemu-flags.nix
index 5d8e898c534c..de355b08918c 100644
--- a/lib/qemu-flags.nix
+++ b/lib/qemu-flags.nix
@@ -3,7 +3,8 @@
 {
 
   qemuNICFlags = nic: net: machine:
-    "-net nic,vlan=${toString nic},macaddr=52:54:00:12:${toString net}:${toString machine},model=virtio " +
-    "-net vde,vlan=${toString nic},sock=$QEMU_VDE_SOCKET_${toString net} ";
+    [ "-net nic,vlan=${toString nic},macaddr=52:54:00:12:${toString net}:${toString machine},model=virtio"
+      "-net vde,vlan=${toString nic},sock=$QEMU_VDE_SOCKET_${toString net}"
+    ];
 
 }
diff --git a/modules/virtualisation/qemu-vm.nix b/modules/virtualisation/qemu-vm.nix
index 91aeb950a156..4b29f38b4207 100644
--- a/modules/virtualisation/qemu-vm.nix
+++ b/modules/virtualisation/qemu-vm.nix
@@ -109,8 +109,8 @@ let
 
     virtualisation.qemu.options =
       mkOption {
-        default = "";
-        example = "-vga std";
+        default = [];
+        example = [ "-vga std" ];
         description = "Options passed to QEMU.";
       };
 
@@ -173,8 +173,8 @@ let
             -append "$(cat ${config.system.build.toplevel}/kernel-params) init=${config.system.build.toplevel}/init regInfo=${regInfo} ${kernelConsole} $QEMU_KERNEL_PARAMS" \
           ''} \
           ${qemuGraphics} \
-          $QEMU_OPTS \
-          ${config.virtualisation.qemu.options}
+          ${toString config.virtualisation.qemu.options} \
+          $QEMU_OPTS
     '';
 
     
@@ -297,6 +297,8 @@ in
     '';
       
   virtualisation.pathsInNixDB = [ config.system.build.toplevel ];
+
+  virtualisation.qemu.options = [ "-usbdevice tablet" ];
   
   # Mount the host filesystem via CIFS, and bind-mount the Nix store
   # of the host into our own filesystem.  We use mkOverride to allow