diff --git a/src/dexorder/bin/backfill_ohlc.py b/src/dexorder/bin/backfill_ohlc.py
index f20def7..6ad23ed 100644
--- a/src/dexorder/bin/backfill_ohlc.py
+++ b/src/dexorder/bin/backfill_ohlc.py
@@ -25,7 +25,7 @@ log = logging.getLogger('dexorder.backfill')
 
 async def finalize_callback(fork: Fork, diffs: Reversible[Union[DiffItem, DiffEntryItem]]):
     ohlc_save(fork, diffs)
-    ts = await get_block_timestamp(fork.head)
+    ts = await get_block_timestamp(fork.head, fork.height)
     log.info(f'backfill completed through block {fork.height} {from_timestamp(ts):%Y-%m-%d %H:%M:%S}')
 
 
diff --git a/src/dexorder/bin/finaldata.py b/src/dexorder/bin/finaldata.py
index d350927..9fb9f44 100644
--- a/src/dexorder/bin/finaldata.py
+++ b/src/dexorder/bin/finaldata.py
@@ -1,4 +1,5 @@
 import asyncio
+import itertools
 import logging
 import sys
 from datetime import timedelta
@@ -28,14 +29,16 @@ ohlcs = FinalOHLCRepository()
 
 async def handle_backfill_uniswap_swaps(swaps: list[EventData]):
     # asynchronously prefetch the block timestamps we'll need
-    hashes = set(swap['blockHash'] for swap in swaps)
-    asyncio.gather(*[get_block_timestamp(h) for h in hashes]).add_done_callback(lambda _:None) # fire and forget, just to build cache
+    block_ids = set((swap['blockHash'], swap['blockNumber']) for swap in swaps)
+    for batch in itertools.batched(block_ids, 4):
+        await asyncio.gather(*[get_block_timestamp(h,n) for h, n in batch])
+
     # now execute the swaps synchronously
     for swap in swaps:
         data = await get_uniswap_data(swap)
         if data is not None:
             pool, time, price = data
-#             log.debug(f'OHLC {pool["address"]} {time} {price}')
+            # log.debug(f'OHLC {pool["address"]} {time} {price}')
             ohlcs.light_update_all(pool['address'], time, price)
 
 async def flush_callback():
diff --git a/src/dexorder/blocks.py b/src/dexorder/blocks.py
index 829d9e3..e1d4d20 100644
--- a/src/dexorder/blocks.py
+++ b/src/dexorder/blocks.py
@@ -19,8 +19,13 @@ from dexorder.util.async_dict import AsyncDict
 log = logging.getLogger(__name__)
 
 
-async def get_block_timestamp(blockid: Union[bytes,int]) -> int:
+async def get_block_timestamp(blockid: Union[bytes,int], block_number: int = None) -> int:
     block = await (fetch_block_by_number(blockid) if type(blockid) is int else get_block(blockid))
+    if block is None:
+        if block_number is not None:
+            block = await fetch_block_by_number(block_number)
+        if block is None:
+            raise ValueError(f'Block {blockid} {block_number} not found')
     return block.timestamp
 
 
diff --git a/src/dexorder/event_handler.py b/src/dexorder/event_handler.py
index e61b801..7fe9641 100644
--- a/src/dexorder/event_handler.py
+++ b/src/dexorder/event_handler.py
@@ -1,4 +1,5 @@
 import asyncio
+import itertools
 import logging
 from uuid import UUID
 
@@ -131,8 +132,10 @@ async def handle_transfer(transfer: EventData):
 
 async def handle_uniswap_swaps(swaps: list[EventData]):
     # asynchronously prefetch the block timestamps we'll need
-    hashes = set(swap['blockHash'] for swap in swaps)
-    await asyncio.gather(*[get_block_timestamp(h) for h in hashes])
+    block_ids = set((swap['blockHash'], swap['blockNumber']) for swap in swaps)
+    for batch in itertools.batched(block_ids, 4):
+        await asyncio.gather(*[get_block_timestamp(h,n) for h, n in batch])
+
     # now execute the swaps synchronously
     for swap in swaps:
         await handle_uniswap_swap(swap)
diff --git a/src/dexorder/ohlc.py b/src/dexorder/ohlc.py
index 842c400..3cff509 100644
--- a/src/dexorder/ohlc.py
+++ b/src/dexorder/ohlc.py
@@ -374,9 +374,10 @@ class OHLCRepository:
             updated = update_ohlc(historical[-1], period, time, price)
             # drop any historical bars that are older than we need
             # oldest_needed = cover the root block time plus one period prior
-            root_hash = current_blockstate.get().root_branch.head
+            root_branch = current_blockstate.get().root_branch
+            root_hash = root_branch.head
             if root_hash is not None:
-                root_timestamp = await get_block_timestamp(root_hash)
+                root_timestamp = await get_block_timestamp(root_hash, root_branch.height)
                 oldest_needed = from_timestamp(root_timestamp) - period
                 # noinspection PyTypeChecker
                 trim = (oldest_needed - historical[0].start) // period
diff --git a/src/dexorder/pools.py b/src/dexorder/pools.py
index 7339c96..5e1df21 100644
--- a/src/dexorder/pools.py
+++ b/src/dexorder/pools.py
@@ -118,6 +118,6 @@ async def get_uniswap_data(swap: EventData) -> Optional[tuple[OldPoolDict, datet
     if pool['exchange'] != Exchange.UniswapV3.value:
         return None
     price: dec = await uniswap_price(pool, sqrt_price)
-    timestamp = await get_block_timestamp(swap['blockHash'])
+    timestamp = await get_block_timestamp(swap['blockHash'], swap['blockNumber'])
     dt = from_timestamp(timestamp)
     return pool, dt, price