diff --git a/backends/hostmem.c b/backends/hostmem.c
index a7bae3d713..624bb7ecd3 100644
--- a/backends/hostmem.c
+++ b/backends/hostmem.c
@@ -274,7 +274,7 @@ static void host_memory_backend_init(Object *obj)
     backend->merge = machine_mem_merge(machine);
     backend->dump = machine_dump_guest_core(machine);
     backend->reserve = true;
-    backend->prealloc_threads = 1;
+    backend->prealloc_threads = machine->smp.cpus;
 }
 
 static void host_memory_backend_post_init(Object *obj)