diff --git a/hw/block/nvme-subsys.h b/hw/block/nvme-subsys.h
index 20d34004c6..65a8bcda03 100644
--- a/hw/block/nvme-subsys.h
+++ b/hw/block/nvme-subsys.h
@@ -14,7 +14,7 @@
     OBJECT_CHECK(NvmeSubsystem, (obj), TYPE_NVME_SUBSYS)
 
 #define NVME_SUBSYS_MAX_CTRLS   32
-#define NVME_SUBSYS_MAX_NAMESPACES  32
+#define NVME_SUBSYS_MAX_NAMESPACES  256
 
 typedef struct NvmeCtrl NvmeCtrl;
 typedef struct NvmeNamespace NvmeNamespace;
diff --git a/hw/block/nvme.h b/hw/block/nvme.h
index cd8d406344..85a7b5a14f 100644
--- a/hw/block/nvme.h
+++ b/hw/block/nvme.h
@@ -10,6 +10,12 @@
 #define NVME_DEFAULT_ZONE_SIZE   (128 * MiB)
 #define NVME_DEFAULT_MAX_ZA_SIZE (128 * KiB)
 
+/*
+ * Subsystem namespace list for allocated namespaces should be larger than
+ * attached namespace list in a controller.
+ */
+QEMU_BUILD_BUG_ON(NVME_MAX_NAMESPACES > NVME_SUBSYS_MAX_NAMESPACES);
+
 typedef struct NvmeParams {
     char     *serial;
     uint32_t num_queues; /* deprecated since 5.1 */