diff --git a/setup.py b/setup.py
index dcb0973..1342153 100644
--- a/setup.py
+++ b/setup.py
@@ -31,7 +31,7 @@ def finalize_options(self):
 
 setup(
     name="tonpy" if not IS_DEV else "tonpy-dev",
-    version="0.0.0.1.3c0" if not IS_DEV else "0.0.0.5.9c1",
+    version="0.0.0.1.4a0" if not IS_DEV else "0.0.0.5.9c1",
     author="Disintar LLP",
     author_email="andrey@head-labs.com",
     description="Types / API for TON blockchain",
diff --git a/src/tonpy/blockscanner/blockscanner.py b/src/tonpy/blockscanner/blockscanner.py
index 17077ec..fc1864c 100644
--- a/src/tonpy/blockscanner/blockscanner.py
+++ b/src/tonpy/blockscanner/blockscanner.py
@@ -805,9 +805,7 @@ def prepare_prev_block_data(self, shards_data, mc_data):
             known_prev_block_data = {}
 
             for x in mc_data:
-                prev_blocks = [
-                    x['block_id'].to_data_nullabe_hashes()
-                ]
+                prev_blocks = []
                 prev_blocks_100 = []
 
                 for i in range(x['block_id'].id.seqno - 16, x['block_id'].id.seqno):
@@ -842,9 +840,7 @@ def prepare_prev_block_data(self, shards_data, mc_data):
                 if i['master'] in known_prev_block_data:
                     i['prev_block_data'] = known_prev_block_data[i['master']]
                 else:
-                    prev_blocks = [
-                        i['master'].to_data_nullabe_hashes()
-                    ]
+                    prev_blocks = []
                     prev_blocks_100 = []
                     for j in range(i['master'] - 16, i['master']):
                         prev_blocks.append(known_mcs[j].to_data())