diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index 6de7809f1a2f9aa3535432fcd0e4565bba399367..946f765f7f791d126a83968f142adf3516bd3836 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -1115,12 +1115,7 @@ static void fw_cfg_mem_realize(DeviceState *dev, Error **errp)
     sysbus_init_mmio(sbd, &s->ctl_iomem);
 
     if (s->data_width > data_ops->valid.max_access_size) {
-        /* memberwise copy because the "old_mmio" member is const */
-        s->wide_data_ops.read       = data_ops->read;
-        s->wide_data_ops.write      = data_ops->write;
-        s->wide_data_ops.endianness = data_ops->endianness;
-        s->wide_data_ops.valid      = data_ops->valid;
-        s->wide_data_ops.impl       = data_ops->impl;
+        s->wide_data_ops = *data_ops;
 
         s->wide_data_ops.valid.max_access_size = s->data_width;
         s->wide_data_ops.impl.max_access_size  = s->data_width;