diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
index 5f0ee9d..8bb61e4 100644
--- a/hw/block/pflash_cfi01.c
+++ b/hw/block/pflash_cfi01.c
@@ -703,7 +703,7 @@ static void pflash_cfi01_realize(DeviceState *dev, Error **errp)
     pflash_t *pfl = CFI_PFLASH01(dev);
     uint64_t total_len;
     int ret;
-    uint64_t blocks_per_device, device_len;
+    uint64_t blocks_per_device, sector_len_per_device, device_len;
     int num_devices;
     Error *local_err = NULL;
 
@@ -727,7 +727,8 @@ static void pflash_cfi01_realize(DeviceState *dev, Error **errp)
      */
     num_devices = pfl->device_width ? (pfl->bank_width / pfl->device_width) : 1;
     blocks_per_device = pfl->nb_blocs / num_devices;
-    device_len = pfl->sector_len * blocks_per_device;
+    sector_len_per_device = pfl->sector_len / num_devices;
+    device_len = sector_len_per_device * blocks_per_device;
 
     /* XXX: to be fixed */
 #if 0
@@ -839,8 +840,8 @@ static void pflash_cfi01_realize(DeviceState *dev, Error **errp)
     /* Erase block region 1 */
     pfl->cfi_table[0x2D] = blocks_per_device - 1;
     pfl->cfi_table[0x2E] = (blocks_per_device - 1) >> 8;
-    pfl->cfi_table[0x2F] = pfl->sector_len >> 8;
-    pfl->cfi_table[0x30] = pfl->sector_len >> 16;
+    pfl->cfi_table[0x2F] = sector_len_per_device >> 8;
+    pfl->cfi_table[0x30] = sector_len_per_device >> 16;
 
     /* Extended */
     pfl->cfi_table[0x31] = 'P';