diff --git a/nimbus/db/db_chain.nim b/nimbus/db/db_chain.nim
index 6d4b8c477..223278a58 100644
--- a/nimbus/db/db_chain.nim
+++ b/nimbus/db/db_chain.nim
@@ -83,8 +83,8 @@ proc getBlockHeader*(self: BaseChainDB; n: BlockNumber): BlockHeader =
   ## Raises BlockNotFound error if the block is not in the DB.
   self.getBlockHeader(self.getBlockHash(n))
 
-proc getScore*(self: BaseChainDB; blockHash: Hash256): int =
-  rlp.decode(self.db.get(blockHashToScoreKey(blockHash).toOpenArray).toRange, int)
+proc getScore*(self: BaseChainDB; blockHash: Hash256): uint64 =
+  rlp.decode(self.db.get(blockHashToScoreKey(blockHash).toOpenArray).toRange, uint64)
 
 iterator findNewAncestors(self: BaseChainDB; header: BlockHeader): BlockHeader =
   ##         Returns the chain leading up from the given header until the first ancestor it has in
@@ -226,7 +226,7 @@ proc persistHeaderToDb*(self: BaseChainDB; header: BlockHeader): seq[BlockHeader
 
   self.addBlockNumberToHashLookup(header)
 
-  var headScore: int
+  var headScore: uint64
   try:
     headScore = self.getScore(self.getCanonicalHead().hash)
   except CanonicalHeadNotFound: