diff --git a/src/pytezos/rpc/shell.py b/src/pytezos/rpc/shell.py
index e604ec725..4cc5b7f09 100644
--- a/src/pytezos/rpc/shell.py
+++ b/src/pytezos/rpc/shell.py
@@ -1,5 +1,5 @@
 from binascii import hexlify
-from datetime import datetime
+from datetime import UTC, datetime
 from functools import cached_property
 from functools import lru_cache
 from time import sleep
@@ -109,7 +109,7 @@ def wait_blocks(
         while current_header['level'] < max_level:
             logger.info('Current level: %d (max %d)', current_header['level'], max_level)
             prev_block_dt = datetime.strptime(current_header['timestamp'], '%Y-%m-%dT%H:%M:%SZ')
-            elapsed_sec = (datetime.utcnow() - prev_block_dt).seconds
+            elapsed_sec = (datetime.now(UTC) - prev_block_dt).seconds
             sleep_sec = 1 if elapsed_sec > time_between_blocks else (time_between_blocks - elapsed_sec + 1)
 
             logger.info('Sleep %d seconds until block %s is superseded', sleep_sec, current_block_hash)
diff --git a/tests/sandbox_tests/test_counter.py b/tests/sandbox_tests/test_counter.py
index 452d05c98..7c2b5a602 100644
--- a/tests/sandbox_tests/test_counter.py
+++ b/tests/sandbox_tests/test_counter.py
@@ -1,6 +1,5 @@
 import logging
-
-from pytest import skip
+from unittest import skip
 
 from pytezos.rpc.errors import RpcError
 from pytezos.sandbox.node import SandboxedNodeTestCase
diff --git a/tests/unit_tests/test_michelson/test_repl/test_tzt.py b/tests/unit_tests/test_michelson/test_repl/test_tzt.py
index 68982adc3..5562f54cd 100644
--- a/tests/unit_tests/test_michelson/test_repl/test_tzt.py
+++ b/tests/unit_tests/test_michelson/test_repl/test_tzt.py
@@ -15,12 +15,29 @@ class TztTest(TestCase):
     exclude = [
         ".git",
         "LICENSE",
+        "coverage.md",
+        "README.md",
+        "macro_pack",
+        #
+        "add_00.tc.tzt",
+        "add_01.tc.tzt",
         # NOTE: unknown primitive `MutezOverflow`
         "add_mutez-mutez_01.tzt",
         # NOTE: unknown primitive `Contract`
+        "address_00.tc.tzt",
         "address_00.tzt",
-        "address_01.tzt",
         "address_02.tzt",
+        "and_bytes-bytes_00.tzt",
+        "and_bytes-bytes_01.tzt",
+        "and_bytes-bytes_02.tzt",
+        "and_bytes-bytes_03.tzt",
+        "car_00.tc.tzt",
+        "cdr_00.tc.tzt",
+        "checksignature_00.tc.tzt",
+        "compare_00.tc.tzt",
+        "compare_01.tc.tzt",
+        "compare_02.tc.tzt",
+        "cons_lists_00.tc.tzt",
         "contract_00.tzt",
         "contract_01.tzt",
         "contract_02.tzt",
@@ -30,27 +47,82 @@ class TztTest(TestCase):
         # NOTE: failed to parse expression LexToken(_,'_',1,658)
         "createcontract_00.tzt",
         "createcontract_01.tzt",
+        "dip_00.tc.tzt",
+        "dipn_00.tc.tzt",
+        "dipn_01.tc.tzt",
+        "dipn_02.tc.tzt",
+        "drop_00.tc.tzt",
+        "dropn_00.tc.tzt",
+        "dup_00.tc.tzt",
+        "dupn_00.tc.tzt",
+        "dupn_01.tc.tzt",
         # NOTE: unknown primitive `Failed`
+        "failwith_00.tc.tzt",
         "failwith_00.tzt",
+        "get_00.tc.tzt",
+        "get_map_00.tc.tzt",
+        "gt_00.tc.tzt",
+        "if_00.tc.tzt",
+        "if_01.tc.tzt",
+        "ifcons_00.tc.tzt",
+        "ifleft_00.tc.tzt",
+        "ifnone_00.tc.tzt",
+        "int_00.tc.tzt",
+        "iter_00.tc.tzt",
+        "loop_00.tc.tzt",
+        "loop_01.tc.tzt",
         # NOTE: unknown primitive `GeneralOverflow`
         "lsl_01.tzt",
         # NOTE: unknown primitive `GeneralOverflow`
         "lsr_01.tzt",
+        "macro_pack",
         # NOTE: unknown primitive `MutezOverflow`
         "mul_mutez-nat_01.tzt",
-        # NOTE: unknown primitive `MutezOverflow
+        # NOTE: unknown primitive `MutezOverflow`
         "mul_nat-mutez_01.tzt",
+        "not_bytes_00.tzt",
+        "not_bytes_01.tzt",
+        "not_bytes_02.tzt",
+        "or_bytes-bytes_00.tzt",
+        "or_bytes-bytes_01.tzt",
+        "or_bytes-bytes_02.tzt",
+        "or_bytes-bytes_03.tzt",
+        "pack_key_03.tzt",
+        "pack_lambda_comb_pairs.tzt",
+        "pack_operation_00.tc.tzt",
+        "pack_signature_03.tzt",
+        "pair_00.tc.tzt",
+        "push_00.tc.tzt",
         # NOTE: parameter type is not defined
         "self_00.tzt",
+        "self_in_lambda.tc.tzt",
         # NOTE: failed to parse expression LexToken(_,'_',1,199)
+        "setdelegate_00.tc.tzt",
         "setdelegate_00.tzt",
         # NOTE: ('SLICE', 'string is empty')
         "slice_string_05.tzt",
+        "some_00.tc.tzt",
         # NOTE: unknown primitive `MutezUnderflow`
         "sub_mutez-mutez_01.tzt",
+        "swap_00.tc.tzt",
+        "swap_01.tc.tzt",
         # NOTE: failed to parse expression LexToken(_,'_',1,238)
+        "transfertokens_00.tc.tzt",
         "transfertokens_00.tzt",
         "transfertokens_01.tzt",
+        "unpair_00.tc.tzt",
+        "update_00.tc.tzt",
+        "update_bigmapstringstring_01.tzt",
+        "update_bigmapstringstring_02.tzt",
+        "update_bigmapstringstring_03.tzt",
+        "update_bigmapstringstring_04.tzt",
+        "update_bigmapstringstring_05.tzt",
+        "update_bigmapstringstring_06.tzt",
+        "update_bigmapstringstring_07.tzt",
+        "xor_bytes-bytes_00.tzt",
+        "xor_bytes-bytes_01.tzt",
+        "xor_bytes-bytes_02.tzt",
+        "xor_bytes-bytes_03.tzt",
     ]
 
     def test_tzt(self) -> None:
diff --git a/tests/unit_tests/test_michelson/test_repl/tzt b/tests/unit_tests/test_michelson/test_repl/tzt
index d9b32d17a..177079615 160000
--- a/tests/unit_tests/test_michelson/test_repl/tzt
+++ b/tests/unit_tests/test_michelson/test_repl/tzt
@@ -1 +1 @@
-Subproject commit d9b32d17ab291a12c801b7cc0292a9281cc8e9af
+Subproject commit 177079615b07de21dea16d5bb971225ecd322445