diff --git a/src/targets/taranis/STM32_USB-Host-Device_Lib_V2.1.0/Libraries/STM32_USB_Device_Library/Class/msc/src/usbd_msc_scsi.c b/src/targets/taranis/STM32_USB-Host-Device_Lib_V2.1.0/Libraries/STM32_USB_Device_Library/Class/msc/src/usbd_msc_scsi.c
index 0df426122..93a20de01 100644
--- a/src/targets/taranis/STM32_USB-Host-Device_Lib_V2.1.0/Libraries/STM32_USB_Device_Library/Class/msc/src/usbd_msc_scsi.c
+++ b/src/targets/taranis/STM32_USB-Host-Device_Lib_V2.1.0/Libraries/STM32_USB_Device_Library/Class/msc/src/usbd_msc_scsi.c
@@ -616,12 +616,18 @@ static int8_t SCSI_Verify10(uint8_t lun , uint8_t *params){
 */
 static int8_t SCSI_CheckAddressRange (uint8_t lun , uint32_t blk_offset , uint16_t blk_nbr)
 {
+  if (USBD_STORAGE_fops->GetCapacity(lun, &SCSI_blk_nbr, &SCSI_blk_size) != 0)
+  {
+    SCSI_SenseCode(lun, NOT_READY, MEDIUM_NOT_PRESENT);
+    return -1;
+  }
   
   if ((blk_offset + blk_nbr) > SCSI_blk_nbr )
   {
     SCSI_SenseCode(lun, ILLEGAL_REQUEST, ADDRESS_OUT_OF_RANGE);
     return -1;
   }
+
   return 0;
 }
 
diff --git a/src/targets/taranis/usbd_storage_msd.cpp b/src/targets/taranis/usbd_storage_msd.cpp
index 87887cd07..7ebca7d70 100644
--- a/src/targets/taranis/usbd_storage_msd.cpp
+++ b/src/targets/taranis/usbd_storage_msd.cpp
@@ -148,9 +148,13 @@ int8_t STORAGE_GetCapacity (uint8_t lun, uint32_t *block_num, uint32_t *block_si
   
     *block_size = 512;
 
-    DWORD sector_count = 0;
-    if (disk_ioctl(0, GET_SECTOR_COUNT, &sector_count) != RES_OK)
-      return -1;
+    static DWORD sector_count = 0;
+    if (sector_count == 0) {
+      if (disk_ioctl(0, GET_SECTOR_COUNT, &sector_count) != RES_OK) {
+        sector_count = 0;
+        return -1;
+      }
+    }
 
     *block_num  = sector_count;
   }