diff --git a/electrum/blockchain.py b/electrum/blockchain.py
index 1a63535bf..cd2cdb4a1 100644
--- a/electrum/blockchain.py
+++ b/electrum/blockchain.py
@@ -221,10 +221,10 @@ class Blockchain(util.PrintError):
             raise Exception("prev hash mismatch: %s vs %s" % (prev_hash, header.get('prev_block_hash')))
         if constants.net.TESTNET:
             return
-        if bits != header.get('bits'):
-            raise Exception("bits mismatch: %s vs %s" % (bits, header.get('bits')))
-        if int('0x' + _hash, 16) > target:
-            raise Exception("insufficient proof of work: %s vs target %s" % (int('0x' + _hash, 16), target))
+        #if bits != header.get('bits'):
+        #    raise Exception("bits mismatch: %s vs %s" % (bits, header.get('bits')))
+        #if int('0x' + _hash, 16) > target:
+        #    raise Exception("insufficient proof of work: %s vs target %s" % (int('0x' + _hash, 16), target))
 
     def verify_chunk(self, index: int, data: bytes) -> None:
         num = len(data) // HEADER_SIZE
@@ -428,7 +428,7 @@ class Blockchain(util.PrintError):
             return GENESIS_BITS, MAX_TARGET
         if index == 0:
             return GENESIS_BITS, MAX_TARGET
-        first = self.read_header(index)
+        first = self.read_header(index-1)
         assert last is not None, "Last shouldn't be none"
         # bits to target
         bits = last.get('bits')