diff --git a/hathor/builder/cli_builder.py b/hathor/builder/cli_builder.py
index f778a4fb2..890897b9a 100644
--- a/hathor/builder/cli_builder.py
+++ b/hathor/builder/cli_builder.py
@@ -59,7 +59,7 @@ def check_or_raise(self, condition: bool, message: str) -> None:
     def create_manager(self, reactor: Reactor) -> HathorManager:
         import hathor
         from hathor.conf.get_settings import get_settings, get_settings_source
-        from hathor.daa import TestMode, _set_test_mode
+        from hathor.daa import TestMode
         from hathor.event.storage import EventMemoryStorage, EventRocksDBStorage, EventStorage
         from hathor.event.websocket.factory import EventWebsocketFactory
         from hathor.p2p.netfilter.utils import add_peer_id_blacklist
@@ -204,7 +204,13 @@ def create_manager(self, reactor: Reactor) -> HathorManager:
             not_support_features=self._args.signal_not_support
         )
 
-        daa = DifficultyAdjustmentAlgorithm(settings=settings)
+        test_mode = TestMode.DISABLED
+        if self._args.test_mode_tx_weight:
+            test_mode = TestMode.TEST_TX_WEIGHT
+            if self.wallet:
+                self.wallet.test_mode = True
+
+        daa = DifficultyAdjustmentAlgorithm(settings=settings, test_mode=test_mode)
 
         vertex_verifiers = VertexVerifiers.create(settings=settings, daa=daa)
         verification_service = VerificationService(verifiers=vertex_verifiers)
@@ -273,11 +279,6 @@ def create_manager(self, reactor: Reactor) -> HathorManager:
         if self._args.bootstrap:
             self.manager.add_peer_discovery(BootstrapPeerDiscovery(self._args.bootstrap))
 
-        if self._args.test_mode_tx_weight:
-            _set_test_mode(TestMode.TEST_TX_WEIGHT)
-            if self.wallet:
-                self.wallet.test_mode = True
-
         if self._args.x_rocksdb_indexes:
             self.log.warn('--x-rocksdb-indexes is now the default, no need to specify it')
             if self._args.memory_indexes:
diff --git a/hathor/daa.py b/hathor/daa.py
index ece55766a..dbf101d63 100644
--- a/hathor/daa.py
+++ b/hathor/daa.py
@@ -21,7 +21,7 @@
 
 from enum import IntFlag
 from math import log
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, ClassVar, Optional
 
 from structlog import get_logger
 
@@ -45,26 +45,20 @@ class TestMode(IntFlag):
     TEST_ALL_WEIGHT = 3
 
 
-TEST_MODE = TestMode.DISABLED
-
-
-def _set_test_mode(mode: TestMode) -> None:
-    global TEST_MODE
-    logger.debug('change DAA test mode', from_mode=TEST_MODE.name, to_mode=mode.name)
-    TEST_MODE = mode
-
-
 class DifficultyAdjustmentAlgorithm:
+    singleton: ClassVar[Optional['DifficultyAdjustmentAlgorithm']] = None
 
-    def __init__(self, *, settings: HathorSettings) -> None:
+    def __init__(self, *, settings: HathorSettings, test_mode: TestMode = TestMode.DISABLED) -> None:
         self._settings = settings
         self.AVG_TIME_BETWEEN_BLOCKS = self._settings.AVG_TIME_BETWEEN_BLOCKS
         self.MIN_BLOCK_WEIGHT = self._settings.MIN_BLOCK_WEIGHT
+        self.TEST_MODE = test_mode
+        DifficultyAdjustmentAlgorithm.singleton = self
 
     @cpu.profiler(key=lambda _, block: 'calculate_block_difficulty!{}'.format(block.hash.hex()))
     def calculate_block_difficulty(self, block: 'Block') -> float:
         """ Calculate block weight according to the ascendents of `block`, using calculate_next_weight."""
-        if TEST_MODE & TestMode.TEST_BLOCK_WEIGHT:
+        if self.TEST_MODE & TestMode.TEST_BLOCK_WEIGHT:
             return 1.0
 
         if block.is_genesis:
@@ -79,7 +73,7 @@ def calculate_next_weight(self, parent_block: 'Block', timestamp: int) -> float:
 
         The weight must not be less than `MIN_BLOCK_WEIGHT`.
         """
-        if TEST_MODE & TestMode.TEST_BLOCK_WEIGHT:
+        if self.TEST_MODE & TestMode.TEST_BLOCK_WEIGHT:
             return 1.0
 
         from hathor.transaction import sum_weights
@@ -166,7 +160,7 @@ def minimum_tx_weight(self, tx: 'Transaction') -> float:
         """
         # In test mode we don't validate the minimum weight for tx
         # We do this to allow generating many txs for testing
-        if TEST_MODE & TestMode.TEST_TX_WEIGHT:
+        if self.TEST_MODE & TestMode.TEST_TX_WEIGHT:
             return 1.0
 
         if tx.is_genesis:
diff --git a/hathor/p2p/peer_id.py b/hathor/p2p/peer_id.py
index 612459e7a..f8eafbdf5 100644
--- a/hathor/p2p/peer_id.py
+++ b/hathor/p2p/peer_id.py
@@ -27,9 +27,10 @@
 from twisted.internet.interfaces import ISSLTransport
 from twisted.internet.ssl import Certificate, CertificateOptions, TLSVersion, trustRootFromCertificates
 
-from hathor import daa
 from hathor.conf.get_settings import get_settings
+from hathor.daa import DifficultyAdjustmentAlgorithm
 from hathor.p2p.utils import connection_string_to_host, discover_dns, generate_certificate
+from hathor.util import not_none
 
 if TYPE_CHECKING:
     from hathor.p2p.protocol import HathorProtocol  # noqa: F401
@@ -344,7 +345,8 @@ def validate_entrypoint(self, protocol: 'HathorProtocol') -> Generator[Any, Any,
                     break
                 host = connection_string_to_host(entrypoint)
                 # TODO: don't use `daa.TEST_MODE` for this
-                result = yield discover_dns(host, daa.TEST_MODE)
+                test_mode = not_none(DifficultyAdjustmentAlgorithm.singleton).TEST_MODE
+                result = yield discover_dns(host, test_mode)
                 if protocol.connection_string in result:
                     # Found the entrypoint
                     found_entrypoint = True
@@ -363,7 +365,8 @@ def validate_entrypoint(self, protocol: 'HathorProtocol') -> Generator[Any, Any,
                 if connection_host == host:
                     found_entrypoint = True
                     break
-                result = yield discover_dns(host, daa.TEST_MODE)
+                test_mode = not_none(DifficultyAdjustmentAlgorithm.singleton).TEST_MODE
+                result = yield discover_dns(host, test_mode)
                 if connection_host in [connection_string_to_host(x) for x in result]:
                     # Found the entrypoint
                     found_entrypoint = True
diff --git a/hathor/simulator/simulator.py b/hathor/simulator/simulator.py
index c9340486f..3384c4232 100644
--- a/hathor/simulator/simulator.py
+++ b/hathor/simulator/simulator.py
@@ -22,7 +22,7 @@
 
 from hathor.builder import BuildArtifacts, Builder
 from hathor.conf.get_settings import get_settings
-from hathor.daa import DifficultyAdjustmentAlgorithm, TestMode, _set_test_mode
+from hathor.daa import DifficultyAdjustmentAlgorithm
 from hathor.manager import HathorManager
 from hathor.p2p.peer_id import PeerId
 from hathor.simulator.clock import HeapClock, MemoryReactorHeapClock
@@ -62,7 +62,6 @@ def _apply_patches(cls):
         Patches:
 
         - disable Transaction.resolve method
-        - set DAA test-mode to DISABLED (will actually run the pow function, that won't actually verify the pow)
         """
         from hathor.transaction import BaseTransaction
 
@@ -74,8 +73,6 @@ def resolve(self: BaseTransaction, update_time: bool = True) -> bool:
         cls._original_resolve = BaseTransaction.resolve
         BaseTransaction.resolve = resolve
 
-        _set_test_mode(TestMode.DISABLED)
-
     @classmethod
     def _remove_patches(cls):
         """ Remove the patches previously applied.
diff --git a/tests/p2p/test_split_brain.py b/tests/p2p/test_split_brain.py
index 7bc2f44c6..7c90aad87 100644
--- a/tests/p2p/test_split_brain.py
+++ b/tests/p2p/test_split_brain.py
@@ -1,7 +1,7 @@
 import pytest
 from mnemonic import Mnemonic
 
-from hathor.daa import TestMode, _set_test_mode
+from hathor.daa import TestMode
 from hathor.graphviz import GraphvizVisualizer
 from hathor.simulator import FakeConnection
 from hathor.wallet import HDWallet
@@ -25,8 +25,8 @@ def create_peer(self, network, unlock_wallet=True):
         wallet = HDWallet(gap_limit=2)
         wallet._manually_initialize()
 
-        _set_test_mode(TestMode.TEST_ALL_WEIGHT)
         manager = super().create_peer(network, wallet=wallet)
+        manager.daa.TEST_MODE = TestMode.TEST_ALL_WEIGHT
         manager.avg_time_between_blocks = 64
 
         # Don't use it anywhere else. It is unsafe to generate mnemonic words like this.
diff --git a/tests/resources/base_resource.py b/tests/resources/base_resource.py
index b7aebc16b..ce9a84c07 100644
--- a/tests/resources/base_resource.py
+++ b/tests/resources/base_resource.py
@@ -2,7 +2,7 @@
 from twisted.web import server
 from twisted.web.test.requesthelper import DummyRequest
 
-from hathor.daa import TestMode, _set_test_mode
+from hathor.daa import TestMode
 from hathor.util import json_dumpb, json_loadb
 from tests import unittest
 
@@ -19,7 +19,7 @@ def setUp(self, *, utxo_index: bool = False, unlock_wallet: bool = True) -> None
                 unlock_wallet=unlock_wallet
             )
             self.manager.allow_mining_without_peers()
-            _set_test_mode(TestMode.TEST_ALL_WEIGHT)
+            self.manager.daa.TEST_MODE = TestMode.TEST_ALL_WEIGHT
 
         def tearDown(self):
             return self.manager.stop()
diff --git a/tests/resources/transaction/test_create_tx.py b/tests/resources/transaction/test_create_tx.py
index 2217ec42b..b42e83c73 100644
--- a/tests/resources/transaction/test_create_tx.py
+++ b/tests/resources/transaction/test_create_tx.py
@@ -2,7 +2,7 @@
 
 from twisted.internet.defer import inlineCallbacks
 
-from hathor.daa import TestMode, _set_test_mode
+from hathor.daa import TestMode
 from hathor.transaction import Transaction
 from hathor.transaction.resources import CreateTxResource
 from hathor.transaction.scripts import P2PKH, create_base_script
@@ -195,7 +195,7 @@ def test_spend_tx_by_script(self):
 
     @inlineCallbacks
     def test_tx_propagate(self):
-        _set_test_mode(TestMode.DISABLED)      # disable test_mode so the weight is not 1
+        self.manager.daa.TEST_MODE = TestMode.DISABLED  # disable test_mode so the weight is not 1
         src_tx = self.unspent_tx
         output_address = 'HNXsVtRUmwDCtpcCJUrH4QiHo9kUKx199A'
         resp = (yield self.web.post('create_tx', {
@@ -233,7 +233,7 @@ def test_tx_propagate(self):
 
     @inlineCallbacks
     def test_tx_propagate_multiple_inputs(self):
-        _set_test_mode(TestMode.DISABLED)      # disable test_mode so the weight is not 1
+        self.manager.daa.TEST_MODE = TestMode.DISABLED  # disable test_mode so the weight is not 1
         output_address = 'HNXsVtRUmwDCtpcCJUrH4QiHo9kUKx199A'
         resp = (yield self.web.post('create_tx', {
             'inputs': [
diff --git a/tests/resources/wallet/test_send_tokens.py b/tests/resources/wallet/test_send_tokens.py
index 0e5cbc533..7136fc85d 100644
--- a/tests/resources/wallet/test_send_tokens.py
+++ b/tests/resources/wallet/test_send_tokens.py
@@ -2,7 +2,7 @@
 
 from twisted.internet.defer import inlineCallbacks
 
-from hathor.daa import TestMode, _set_test_mode
+from hathor.daa import TestMode
 from hathor.p2p.resources import MiningResource
 from hathor.wallet.resources import BalanceResource, HistoryResource, SendTokensResource
 from tests import unittest
@@ -168,7 +168,7 @@ def test_post(self):
 
     @inlineCallbacks
     def test_tx_weight(self):
-        _set_test_mode(TestMode.DISABLED)
+        self.manager.daa.TEST_MODE = TestMode.DISABLED
         add_new_blocks(self.manager, 3, advance_clock=1)
         add_blocks_unlock_reward(self.manager)
         self.reactor.advance(3)
diff --git a/tests/tx/test_blockchain.py b/tests/tx/test_blockchain.py
index f52228c60..f758706d3 100644
--- a/tests/tx/test_blockchain.py
+++ b/tests/tx/test_blockchain.py
@@ -1,7 +1,7 @@
 from itertools import chain
 
 from hathor.conf import HathorSettings
-from hathor.daa import DifficultyAdjustmentAlgorithm, TestMode, _set_test_mode
+from hathor.daa import DifficultyAdjustmentAlgorithm, TestMode
 from hathor.transaction import sum_weights
 from hathor.transaction.storage import TransactionMemoryStorage
 from tests import unittest
@@ -390,8 +390,8 @@ def test_block_rewards(self):
 
     def test_daa_sanity(self):
         # sanity test the DAA
-        _set_test_mode(TestMode.DISABLED)
         manager = self.create_peer('testnet', tx_storage=self.tx_storage)
+        manager.daa.TEST_MODE = TestMode.DISABLED
         N = settings.BLOCK_DIFFICULTY_N_BLOCKS
         T = settings.AVG_TIME_BETWEEN_BLOCKS
         manager.avg_time_between_blocks = T
@@ -417,7 +417,7 @@ def test_daa_sanity(self):
             self.assertLess(new_weight, base_weight)
 
     def test_daa_weight_decay_amount(self):
-        _set_test_mode(TestMode.DISABLED)
+        self.daa.TEST_MODE = TestMode.DISABLED
         amount = settings.WEIGHT_DECAY_AMOUNT
 
         for distance in range(0, settings.WEIGHT_DECAY_ACTIVATE_DISTANCE, 10):
@@ -434,8 +434,8 @@ def test_daa_weight_decay_amount(self):
         self.assertAlmostEqual(self.daa.get_weight_decay_amount(distance), 11 * amount)
 
     def test_daa_weight_decay_blocks(self):
-        _set_test_mode(TestMode.DISABLED)
         manager = self.create_peer('testnet', tx_storage=self.tx_storage)
+        manager.daa.TEST_MODE = TestMode.DISABLED
         amount = settings.WEIGHT_DECAY_AMOUNT
 
         manager.daa.AVG_TIME_BETWEEN_BLOCKS = settings.AVG_TIME_BETWEEN_BLOCKS
diff --git a/tests/tx/test_cache_storage.py b/tests/tx/test_cache_storage.py
index a7832bd1c..c91f69db9 100644
--- a/tests/tx/test_cache_storage.py
+++ b/tests/tx/test_cache_storage.py
@@ -1,4 +1,4 @@
-from hathor.daa import TestMode, _set_test_mode
+from hathor.daa import TestMode
 from hathor.transaction import Transaction, TransactionMetadata
 from hathor.transaction.storage import TransactionCacheStorage
 from tests import unittest
@@ -144,7 +144,7 @@ def test_flush_thread(self):
         self.cache_storage._flush_to_storage(self.cache_storage.dirty_txs.copy())
 
     def test_topological_sort_dfs(self):
-        _set_test_mode(TestMode.TEST_ALL_WEIGHT)
+        self.manager.daa.TEST_MODE = TestMode.TEST_ALL_WEIGHT
         add_new_blocks(self.manager, 11, advance_clock=1)
         tx = add_new_transactions(self.manager, 1, advance_clock=1)[0]
 
diff --git a/tests/tx/test_genesis.py b/tests/tx/test_genesis.py
index d1e8b9d13..baa284b87 100644
--- a/tests/tx/test_genesis.py
+++ b/tests/tx/test_genesis.py
@@ -1,5 +1,5 @@
 from hathor.conf import HathorSettings
-from hathor.daa import DifficultyAdjustmentAlgorithm, TestMode, _set_test_mode
+from hathor.daa import DifficultyAdjustmentAlgorithm, TestMode
 from hathor.transaction.storage import TransactionMemoryStorage
 from hathor.verification.verification_service import VerificationService, VertexVerifiers
 from hathor.verification.vertex_verifier import VertexVerifier
@@ -69,10 +69,10 @@ def test_genesis_weight(self):
 
         # Validate the block and tx weight
         # in test mode weight is always 1
-        _set_test_mode(TestMode.TEST_ALL_WEIGHT)
+        self._daa.TEST_MODE = TestMode.TEST_ALL_WEIGHT
         self.assertEqual(self._daa.calculate_block_difficulty(genesis_block), 1)
         self.assertEqual(self._daa.minimum_tx_weight(genesis_tx), 1)
 
-        _set_test_mode(TestMode.DISABLED)
+        self._daa.TEST_MODE = TestMode.DISABLED
         self.assertEqual(self._daa.calculate_block_difficulty(genesis_block), genesis_block.weight)
         self.assertEqual(self._daa.minimum_tx_weight(genesis_tx), genesis_tx.weight)
diff --git a/tests/tx/test_tx.py b/tests/tx/test_tx.py
index d245361ea..bbab21cd5 100644
--- a/tests/tx/test_tx.py
+++ b/tests/tx/test_tx.py
@@ -3,7 +3,7 @@
 from math import isinf, isnan
 
 from hathor.crypto.util import decode_address, get_address_from_public_key, get_private_key_from_bytes
-from hathor.daa import TestMode, _set_test_mode
+from hathor.daa import TestMode
 from hathor.transaction import MAX_OUTPUT_VALUE, Block, Transaction, TxInput, TxOutput
 from hathor.transaction.exceptions import (
     BlockWithInputs,
@@ -630,8 +630,8 @@ def test_update_timestamp(self):
         self.assertEquals(tx.timestamp, ts)
 
     def test_propagation_error(self):
-        _set_test_mode(TestMode.DISABLED)
         manager = self.create_peer('testnet', unlock_wallet=True)
+        manager.daa.TEST_MODE = TestMode.DISABLED
 
         # 1. propagate genesis
         genesis_block = self.genesis_blocks[0]
diff --git a/tests/tx/test_tx_storage.py b/tests/tx/test_tx_storage.py
index b2f83a0a2..643366769 100644
--- a/tests/tx/test_tx_storage.py
+++ b/tests/tx/test_tx_storage.py
@@ -9,7 +9,7 @@
 from twisted.trial import unittest
 
 from hathor.conf import HathorSettings
-from hathor.daa import TestMode, _set_test_mode
+from hathor.daa import TestMode
 from hathor.transaction import Block, Transaction, TxInput, TxOutput
 from hathor.transaction.scripts import P2PKH
 from hathor.transaction.storage.exceptions import TransactionDoesNotExist
@@ -155,7 +155,7 @@ def test_storage_basic_v2(self):
         self.assertEqual(set(tx_parents_hash), {self.genesis_txs[0].hash, self.genesis_txs[1].hash})
 
     def test_vertices_count(self):
-        _set_test_mode(TestMode.TEST_ALL_WEIGHT)
+        self.manager.daa.TEST_MODE = TestMode.TEST_ALL_WEIGHT
 
         blocks_count = 1
         txs_count = 2
@@ -532,7 +532,7 @@ def _add_new_block(self, parents=None):
         return block
 
     def test_best_block_tips_cache(self):
-        _set_test_mode(TestMode.TEST_ALL_WEIGHT)
+        self.manager.daa.TEST_MODE = TestMode.TEST_ALL_WEIGHT
         self.manager.wallet.unlock(b'MYPASS')
         spent_blocks = add_new_blocks(self.manager, 10)
         self.assertEqual(self.tx_storage._best_block_tips_cache, [spent_blocks[-1].hash])
@@ -544,7 +544,7 @@ def test_best_block_tips_cache(self):
         self.assertEqual(self.tx_storage._best_block_tips_cache, [latest_blocks[-1].hash])
 
     def test_topological_sort(self):
-        _set_test_mode(TestMode.TEST_ALL_WEIGHT)
+        self.manager.daa.TEST_MODE = TestMode.TEST_ALL_WEIGHT
         _total = 0
         blocks = add_new_blocks(self.manager, 1, advance_clock=1)
         _total += len(blocks)
diff --git a/tests/unittest.py b/tests/unittest.py
index 881c613e6..51a867077 100644
--- a/tests/unittest.py
+++ b/tests/unittest.py
@@ -12,7 +12,7 @@
 from hathor.builder import BuildArtifacts, Builder
 from hathor.conf import HathorSettings
 from hathor.conf.get_settings import get_settings
-from hathor.daa import TestMode, _set_test_mode
+from hathor.daa import DifficultyAdjustmentAlgorithm, TestMode
 from hathor.p2p.peer_id import PeerId
 from hathor.p2p.sync_version import SyncVersion
 from hathor.simulator.clock import MemoryReactorHeapClock
@@ -104,7 +104,6 @@ class TestCase(unittest.TestCase):
     seed_config: Optional[int] = None
 
     def setUp(self):
-        _set_test_mode(TestMode.TEST_ALL_WEIGHT)
         self.tmpdirs = []
         self.clock = TestMemoryReactorClock()
         self.clock.advance(time.time())
@@ -183,7 +182,7 @@ def create_peer_from_builder(self, builder, start_manager=True):
     def create_peer(self, network, peer_id=None, wallet=None, tx_storage=None, unlock_wallet=True, wallet_index=False,
                     capabilities=None, full_verification=True, enable_sync_v1=None, enable_sync_v2=None,
                     checkpoints=None, utxo_index=False, event_manager=None, use_memory_index=None, start_manager=True,
-                    pubsub=None, event_storage=None, enable_event_queue=None, use_memory_storage=None, daa=None):
+                    pubsub=None, event_storage=None, enable_event_queue=None, use_memory_storage=None):
 
         enable_sync_v1, enable_sync_v2 = self._syncVersionFlags(enable_sync_v1, enable_sync_v2)
 
@@ -246,9 +245,8 @@ def create_peer(self, network, peer_id=None, wallet=None, tx_storage=None, unloc
         if utxo_index:
             builder.enable_utxo_index()
 
-        if daa:
-            builder.set_daa(daa)
-
+        daa = DifficultyAdjustmentAlgorithm(settings=self._settings, test_mode=TestMode.TEST_ALL_WEIGHT)
+        builder.set_daa(daa)
         manager = self.create_peer_from_builder(builder, start_manager=start_manager)
 
         # XXX: just making sure that tests set this up correctly