diff --git a/mtkclient/Library/Exploit/amonet.py b/mtkclient/Library/Exploit/amonet.py
index c2ced4ac..bd7c8412 100644
--- a/mtkclient/Library/Exploit/amonet.py
+++ b/mtkclient/Library/Exploit/amonet.py
@@ -26,6 +26,7 @@ def da_read_write(self, address, length, data=None, check_result=True):
         if self.chipconfig.blacklist:
             self.hwcrypto.disable_range_blacklist("gcpu", self.mtk)
         if data is None:
+            old = 0
             data=bytearray()
             for addr in range(address, address+length, 16):
                 prog = int(addr / length * 100)
@@ -138,4 +139,4 @@ def dump_brom(self, filename, dump_ptr=None, length=0x20000):
                     old = round(prog, 1)
                 wf.write(self.hwcrypto.gcpu.aes_read_cbc(addr))
         print_progress(100, 100, prefix='Progress:', suffix='Complete', bar_length=50)
-        return True
\ No newline at end of file
+        return True