diff --git a/backends/hostmem.c b/backends/hostmem.c
index a70867b..327f9ee 100644
--- a/backends/hostmem.c
+++ b/backends/hostmem.c
@@ -280,6 +280,7 @@
     /* TODO: convert access to globals to compat properties */
     backend->merge = machine_mem_merge(machine);
     backend->dump = machine_dump_guest_core(machine);
+    backend->prealloc_threads = 1;
 }
 
 static void host_memory_backend_post_init(Object *obj)
diff --git a/target/i386/hax-windows.c b/target/i386/hax-windows.c
index 0ba488c..863c2bc 100644
--- a/target/i386/hax-windows.c
+++ b/target/i386/hax-windows.c
@@ -185,12 +185,12 @@
 
 static char *hax_vm_devfs_string(int vm_id)
 {
-    return g_strdup_printf("/dev/hax_vm/vm%02d", vm_id);
+    return g_strdup_printf("\\\\.\\hax_vm%02d", vm_id);
 }
 
 static char *hax_vcpu_devfs_string(int vm_id, int vcpu_id)
 {
-    return g_strdup_printf("/dev/hax_vm%02d/vcpu%02d", vm_id, vcpu_id);
+    return g_strdup_printf("\\\\.\\hax_vm%02d_vcpu%02d", vm_id, vcpu_id);
 }
 
 int hax_host_create_vm(struct hax_state *hax, int *vmid)
diff --git a/tests/qtest/numa-test.c b/tests/qtest/numa-test.c
index 2f9b7f6..e1ed6d4 100644
--- a/tests/qtest/numa-test.c
+++ b/tests/qtest/numa-test.c
@@ -455,7 +455,7 @@
     cli = make_cli(data, "-nodefaults --preconfig "
                          "-smp 2,sockets=2 "
                          "-m 128M,slots=2,maxmem=1G "
-                         "-object memory-backend-ram,size=64M,id=m0 "
+                         "-object memory-backend-ram,size=64M,id=m0,prealloc=y "
                          "-object memory-backend-ram,size=64M,id=m1 "
                          "-numa node,nodeid=0,memdev=m0");
     qs = qtest_init(cli);