diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 895446f17c2b5f5a98172565cd105d78000ddd4d..c3a1e92e51a53b9ba254e6c249a5a76ddaeff03c 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -1494,7 +1494,7 @@ static void virt_machine_class_init(ObjectClass *oc, void *data)
      * it later in machvirt_init, where we have more information about the
      * configuration of the particular instance.
      */
-    mc->max_cpus = MAX_CPUMASK_BITS;
+    mc->max_cpus = 255;
     mc->has_dynamic_sysbus = true;
     mc->block_default_type = IF_VIRTIO;
     mc->no_cdrom = 1;
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index ddb7438434804135fca5b1938bfcb2b645499dba..486f57d6f6555da2ddb35537492e3821808305cd 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -2438,7 +2438,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
     mc->init = ppc_spapr_init;
     mc->reset = ppc_spapr_reset;
     mc->block_default_type = IF_SCSI;
-    mc->max_cpus = MAX_CPUMASK_BITS;
+    mc->max_cpus = 255;
     mc->no_parallel = 1;
     mc->default_boot_order = "";
     mc->default_ram_size = 512 * M_BYTE;
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index b66883328df229e9ab9687a1076870478433bbfe..66c6f1577e0cc30c8c829978d2992a5aba5257de 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -173,7 +173,7 @@ extern int mem_prealloc;
  *
  * Note that cpu->get_arch_id() may be larger than MAX_CPUMASK_BITS.
  */
-#define MAX_CPUMASK_BITS 255
+#define MAX_CPUMASK_BITS 288
 
 #define MAX_OPTION_ROMS 16
 typedef struct QEMUOptionRom {