diff --git a/lbry/wallet/server/leveldb.py b/lbry/wallet/server/leveldb.py
index 08b4bdbbd..3adf8ed44 100644
--- a/lbry/wallet/server/leveldb.py
+++ b/lbry/wallet/server/leveldb.py
@@ -280,6 +280,7 @@ def tx_merkle(tx_num, tx_height):
         return ctx.merkle_tx_cache[(tx_num, tx_height)]
     if tx_height not in ctx.block_txs_cache:
         block_txs = list(db.iterator(
+            prefix=TX_HASH_PREFIX,
             start=TX_HASH_PREFIX + util.pack_be_uint64(tx_counts[tx_height - 1]),
             stop=None if tx_height + 1 == len(tx_counts) else
             TX_HASH_PREFIX + util.pack_be_uint64(tx_counts[tx_height]), include_key=False
@@ -288,6 +289,7 @@ def tx_merkle(tx_num, tx_height):
             ctx.block_txs_cache[tx_height] = block_txs
     else:
         block_txs = ctx.block_txs_cache.get(tx_height, uncached)
+
     branch, root = ctx.merkle.branch_and_root(block_txs, tx_pos)
     merkle = {
         'block_height': tx_height,
diff --git a/lbry/wallet/server/storage.py b/lbry/wallet/server/storage.py
index ca24daa99..ff6ecf4a3 100644
--- a/lbry/wallet/server/storage.py
+++ b/lbry/wallet/server/storage.py
@@ -153,12 +153,11 @@ class RocksDBIterator:
     ]
 
     def __init__(self, db, prefix=None, start=None, stop=None, include_key=True, include_value=True, reverse=False):
-        assert (start is None and stop is None) or (prefix is None), 'cannot use start/stop and prefix'
         self.start = start
         self.prefix = prefix
         self.stop = stop
         self.iterator = db.iteritems() if not reverse else reversed(db.iteritems())
-        if prefix is not None:
+        if prefix is not None and start is None:
             self.iterator.seek(prefix)
         elif start is not None:
             self.iterator.seek(start)