diff --git a/eth/common/eth_types.nim b/eth/common/eth_types.nim
index 6fbde9f..fc4edf4 100644
--- a/eth/common/eth_types.nim
+++ b/eth/common/eth_types.nim
@@ -180,6 +180,12 @@ when BlockNumber is int64:
   template toBlockNumber*(n: SomeInteger): BlockNumber =
     int64(n)
 
+  template toBlockNumber*(n: UInt256): BlockNumber =
+    n.toInt
+
+  template toInt*(n: BlockNumber): int =
+    int(n)
+
 else:
   template vmWordToBlockNumber*(word: VMWord): BlockNumber =
     word
@@ -190,6 +196,12 @@ else:
   template toBlockNumber*(n: SomeInteger): BlockNumber =
     u256(n)
 
+  template toBlockNumber*(n: UInt256): BlockNumber =
+    n
+
+  template u256*(n: BlockNumber): UInt256 =
+    n
+
 proc toBlockNonce*(n: uint64): BlockNonce =
   bigEndian64(addr result[0], unsafeAddr n)
 
@@ -303,7 +315,7 @@ proc read*(rlp: var Rlp, T: typedesc[HashOrNum]): T =
   if rlp.blobLen == 32:
     result = HashOrNum(isHash: true, hash: rlp.read(Hash256))
   else:
-    result = HashOrNum(isHash: false, number: rlp.read(UInt256))
+    result = HashOrNum(isHash: false, number: rlp.read(BlockNumber))
 
 proc append*(rlpWriter: var RlpWriter, t: Time) {.inline.} =
   rlpWriter.append(t.toUnix())
diff --git a/eth/p2p/blockchain_sync.nim b/eth/p2p/blockchain_sync.nim
index 361b827..9ae4dae 100644
--- a/eth/p2p/blockchain_sync.nim
+++ b/eth/p2p/blockchain_sync.nim
@@ -40,7 +40,7 @@ proc hash*(p: Peer): Hash {.inline.} = hash(cast[pointer](p))
 
 proc endIndex(b: WantedBlocks): BlockNumber =
   result = b.startIndex
-  result += (b.numBlocks - 1).u256
+  result += (b.numBlocks - 1).toBlockNumber
 
 proc availableWorkItem(ctx: SyncContext): int =
   var maxPendingBlock = ctx.finalizedBlock
diff --git a/eth/p2p/blockchain_utils.nim b/eth/p2p/blockchain_utils.nim
index 23f5c89..024d609 100644
--- a/eth/p2p/blockchain_utils.nim
+++ b/eth/p2p/blockchain_utils.nim
@@ -10,16 +10,15 @@ proc getBlockHeaders*(db: AbstractChainDB,
   var foundBlock: BlockHeader
   if db.getBlockHeader(req.startBlock, foundBlock):
     result.add foundBlock
-    # Quick sanity check for lower bounds, code should be safe though without.
-    if not req.reverse or (foundBlock.blockNumber >= (req.skip + 1).toBlockNumber):
-      while uint64(result.len) < req.maxResults:
-        if not req.reverse:
-          if not db.getSuccessorHeader(foundBlock, foundBlock, req.skip):
-            break
-        else:
-          if not db.getAncestorHeader(foundBlock, foundBlock, req.skip):
-            break
-        result.add foundBlock
+
+    while uint64(result.len) < req.maxResults:
+      if not req.reverse:
+        if not db.getSuccessorHeader(foundBlock, foundBlock, req.skip):
+          break
+      else:
+        if not db.getAncestorHeader(foundBlock, foundBlock, req.skip):
+          break
+      result.add foundBlock
 
 
 template fetcher*(fetcherName, fetchingFunc, InputType, ResultType: untyped) =