diff --git a/trunk/src/fw_downloader.cpp b/trunk/src/fw_downloader.cpp
index f2d89f4b3815a0a1b620f907ce0ae805f63d0830..ca8a6ce01acdcfae8c4b5e8975f1c7b92dbbe106 100755
--- a/trunk/src/fw_downloader.cpp
+++ b/trunk/src/fw_downloader.cpp
@@ -45,7 +45,8 @@ void show_help(char *name) {
 
 int main(int argc,char *argv[])
 {
-  unsigned int baudrate=57600,left,addr,start_addr=0x00000000,len,base,data_len;
+  unsigned int baudrate=57600,left,addr,start_addr=0x00000000,len,base;
+  size_t data_len;
   unsigned short int erase_pages=0xFFFF,device_id;
   unsigned char bootloader_ver,buffer[256];
   flash_op operation=flash_none;