diff --git a/scripts/joinmarket-qt.py b/scripts/joinmarket-qt.py
index 39a0e3aeb..d869e69f0 100755
--- a/scripts/joinmarket-qt.py
+++ b/scripts/joinmarket-qt.py
@@ -2449,6 +2449,8 @@ def onTabChange(i):
 mainWindow.resize(600, 500)
 if get_network() == 'testnet':
     suffix = ' - Testnet'
+elif get_network() == 'testnet4':
+    suffix = ' - Testnet4'
 elif get_network() == 'signet':
     suffix = ' - Signet'
 else:
diff --git a/scripts/qtsupport.py b/scripts/qtsupport.py
index c900178cf..134bdd222 100644
--- a/scripts/qtsupport.py
+++ b/scripts/qtsupport.py
@@ -61,7 +61,7 @@
                 'absurd_fee_per_kb': 'amount'}
 config_tips = {
     'blockchain_source': 'options: bitcoin-rpc, regtest (for testing)',
-    'network': 'one of "signet", "testnet" or "mainnet"',
+    'network': 'one of "signet", "testnet", "testnet4" or "mainnet"',
     'checktx': 'whether to check fees before completing transaction',
     'rpc_host':
     'the host for bitcoind; only used if blockchain_source is bitcoin-rpc',
diff --git a/src/jmbitcoin/secp256k1_deterministic.py b/src/jmbitcoin/secp256k1_deterministic.py
index eb4fa3dbd..5c3050c6f 100644
--- a/src/jmbitcoin/secp256k1_deterministic.py
+++ b/src/jmbitcoin/secp256k1_deterministic.py
@@ -12,8 +12,10 @@
 TESTNET_PUBLIC = b'\x04\x35\x87\xCF'
 SIGNET_PRIVATE = b'\x04\x35\x83\x94'
 SIGNET_PUBLIC = b'\x04\x35\x87\xCF'
-PRIVATE = [MAINNET_PRIVATE, TESTNET_PRIVATE, SIGNET_PRIVATE]
-PUBLIC = [MAINNET_PUBLIC, TESTNET_PUBLIC, SIGNET_PUBLIC]
+TESTNET4_PRIVATE = b'\x04\x35\x83\x94'
+TESTNET4_PUBLIC = b'\x04\x35\x87\xCF'
+PRIVATE = [MAINNET_PRIVATE, TESTNET_PRIVATE, SIGNET_PRIVATE, TESTNET4_PRIVATE]
+PUBLIC = [MAINNET_PUBLIC, TESTNET_PUBLIC, SIGNET_PUBLIC, TESTNET4_PUBLIC]
 
 privtopub = privkey_to_pubkey
 
diff --git a/src/jmbitcoin/secp256k1_main.py b/src/jmbitcoin/secp256k1_main.py
index 44204f920..68c9f8d7f 100644
--- a/src/jmbitcoin/secp256k1_main.py
+++ b/src/jmbitcoin/secp256k1_main.py
@@ -22,8 +22,9 @@
 N = 115792089237316195423570985008687907852837564279074904382605163141518161494337
 
 BTC_P2PK_VBYTE = {"mainnet": b'\x00', "testnet": b'\x6f', "signet": b'\x6f',
-    "regtest": 100}
-BTC_P2SH_VBYTE = {"mainnet": b'\x05', "testnet": b'\xc4', "signet": b'\xc4'}
+    "regtest": 100, "testnet4": b'\x6f'}
+BTC_P2SH_VBYTE = {"mainnet": b'\x05', "testnet": b'\xc4', "signet": b'\xc4',
+    "testnet4": b'\xc4'}
 
 """PoDLE related primitives
 """
diff --git a/src/jmclient/blockchaininterface.py b/src/jmclient/blockchaininterface.py
index 3251eea26..af06b744b 100644
--- a/src/jmclient/blockchaininterface.py
+++ b/src/jmclient/blockchaininterface.py
@@ -342,7 +342,7 @@ def __init__(self, jsonRpc: JsonRpc, network: str, wallet_name: str) -> None:
         actualNet = blockchainInfo['chain']
 
         netmap = {'main': 'mainnet', 'test': 'testnet', 'regtest': 'regtest',
-            'signet': 'signet'}
+            'signet': 'signet', 'testnet4': 'testnet4'}
         if netmap[actualNet] != network and \
                 (not (actualNet == "regtest" and network == "testnet")):
             #special case of regtest and testnet having the same addr format
diff --git a/src/jmclient/configure.py b/src/jmclient/configure.py
index 9a31a5e90..fcdfd562e 100644
--- a/src/jmclient/configure.py
+++ b/src/jmclient/configure.py
@@ -121,12 +121,13 @@ def jm_single() -> AttributeDict:
 # to Bitcoin Core; note that use of this option for any other purpose is currently unsupported.
 blockchain_source = bitcoin-rpc
 
-# options: signet, testnet, mainnet
+# options: signet, testnet, testnet4, mainnet
 # Note: for regtest, use network = testnet
 network = mainnet
 
 rpc_host = localhost
-# default ports are 8332 for mainnet, 18443 for regtest, 18332 for testnet, 38332 for signet
+# default ports are 8332 for mainnet, 18443 for regtest, 18332 for testnet,
+# 38332 for signet, 48332 for testnet4
 rpc_port =
 
 # Use either rpc_user / rpc_password pair or rpc_cookie_file.
@@ -183,6 +184,9 @@ def jm_single() -> AttributeDict:
 # for SIGNET (testing network):
 # directory_nodes = rr6f6qtleiiwic45bby4zwmiwjrj3jsbmcvutwpqxjziaydjydkk5iad.onion:5222,k74oyetjqgcamsyhlym2vgbjtvhcrbxr4iowd4nv4zk5sehw4v665jad.onion:5222,y2ruswmdbsfl4hhwwiqz4m3sx6si5fr6l3pf62d4pms2b53wmagq3eqd.onion:5222
 
+# for TESTNET4 (testing network):
+# directory_nodes = qibbq5s7come4ihuroa232pf2pf6kse4wsu3n753fjkyfn6bhyllhdyd.onion:5222
+
 # This setting is ONLY for developer regtest setups,
 # running multiple bots at once. Don't alter it otherwise
 regtest_count = 0,0
@@ -771,7 +775,7 @@ def load_program_config(config_path: str = "", bs: Optional[str] = None,
                   "location cmtdata/commitments.json")
     if get_network() != "mainnet":
         # no need to be flexible for tests; note this is used
-        # for regtest, signet and testnet3
+        # for regtest, signet, testnet3 and testnet4
         global_singleton.commit_file_location = "cmtdata/" + get_network() + \
             "_commitments.json"
     set_commitment_file(os.path.join(config_path,
@@ -872,7 +876,7 @@ def get_blockchain_interface_instance(_config: ConfigParser):
         BitcoinCoreNoHistoryInterface
     source = _config.get("BLOCKCHAIN", "blockchain_source")
     network = get_network()
-    testnet = (network == 'testnet' or network == 'signet')
+    testnet = (network in ['testnet', 'testnet4', 'signet'])
 
     if source in ('bitcoin-rpc', 'regtest', 'bitcoin-rpc-no-history'):
         rpc_host = _config.get("BLOCKCHAIN", "rpc_host")
@@ -884,6 +888,8 @@ def get_blockchain_interface_instance(_config: ConfigParser):
                 rpc_port = 18443
             elif network == 'testnet':
                 rpc_port = 18332
+            elif network == 'testnet4':
+                rpc_port = 48332
             elif network == 'signet':
                 rpc_port = 38332
             else:
diff --git a/src/jmclient/cryptoengine.py b/src/jmclient/cryptoengine.py
index 065e3eeac..1ea73cbd7 100644
--- a/src/jmclient/cryptoengine.py
+++ b/src/jmclient/cryptoengine.py
@@ -17,11 +17,13 @@
 TYPE_P2PKH, TYPE_P2SH_P2WPKH, TYPE_P2WPKH, TYPE_P2SH_M_N, TYPE_TIMELOCK_P2WSH, \
     TYPE_SEGWIT_WALLET_FIDELITY_BONDS, TYPE_WATCHONLY_FIDELITY_BONDS, \
     TYPE_WATCHONLY_TIMELOCK_P2WSH, TYPE_WATCHONLY_P2WPKH, TYPE_P2WSH, TYPE_P2TR = range(11)
-NET_MAINNET, NET_TESTNET, NET_SIGNET = range(3)
+NET_MAINNET, NET_TESTNET, NET_SIGNET, NET_TESTNET4 = range(4)
 NET_MAP = {'mainnet': NET_MAINNET, 'testnet': NET_TESTNET,
-    'signet': NET_SIGNET}
-WIF_PREFIX_MAP = {'mainnet': b'\x80', 'testnet': b'\xef', 'signet': b'\xef'}
-BIP44_COIN_MAP = {'mainnet': 2**31, 'testnet': 2**31 + 1, 'signet': 2**31 + 1}
+           'signet': NET_SIGNET, 'testnet4': NET_TESTNET4}
+WIF_PREFIX_MAP = {'mainnet': b'\x80', 'testnet': b'\xef', 'signet': b'\xef',
+                  'testnet4': b'\xef'}
+BIP44_COIN_MAP = {'mainnet': 2**31, 'testnet': 2**31 + 1, 'signet': 2**31 + 1,
+                  'testnet4': 2**31 + 1}
 
 BIP32_PUB_PREFIX = "xpub"
 BIP49_PUB_PREFIX = "ypub"
diff --git a/src/jmclient/wallet.py b/src/jmclient/wallet.py
index 5ac786fee..19bcc1932 100644
--- a/src/jmclient/wallet.py
+++ b/src/jmclient/wallet.py
@@ -416,7 +416,7 @@ def __init__(self, storage, gap_limit=6, merge_algorithm_name=None,
         assert self._cache is not None
         assert self.max_mixdepth is not None
         assert self.max_mixdepth >= 0
-        assert self.network in ('mainnet', 'testnet', 'signet')
+        assert self.network in ('mainnet', 'testnet', 'signet', 'testnet4')
 
         if mixdepth is not None:
             assert mixdepth >= 0
@@ -479,12 +479,13 @@ def initialize(cls, storage, network, max_mixdepth=2, timestamp=None,
 
         args:
             storage: a Storage object
-            network: str, network we are on, 'mainnet', 'testnet' or 'signet'
+            network: str, network we are on, 'mainnet', 'testnet', 'signet'
+            or 'testnet4'
             max_mixdepth: int, number of the highest mixdepth
             timestamp: bytes or None, defaults to the current time
             write: execute storage.save()
         """
-        assert network in ('mainnet', 'testnet', 'signet')
+        assert network in ('mainnet', 'testnet', 'signet', 'testnet4')
         assert max_mixdepth >= 0
 
         if storage.data != {}:
diff --git a/src/jmclient/yieldgenerator.py b/src/jmclient/yieldgenerator.py
index 8be330771..d6a7873da 100644
--- a/src/jmclient/yieldgenerator.py
+++ b/src/jmclient/yieldgenerator.py
@@ -477,8 +477,8 @@ def ygmain(ygclass, nickserv_password='', gaplimit=6):
         if jm_single().config.get("BLOCKCHAIN", "network") == "mainnet":
             jlog.error("You have enabled SNICKER on mainnet, this is not "
                        "yet supported for yieldgenerators; either use "
-                       "signet/regtest/testnet, or run SNICKER manually "
-                       "with snicker/receive-snicker.py.")
+                       "signet/regtest/testnet/testnet4, or run SNICKER "
+                       "manually with snicker/receive-snicker.py.")
             sys.exit(EXIT_ARGERROR)
         snicker_r = SNICKERReceiver(wallet_service)
         servers = jm_single().config.get("SNICKER", "servers").split(",")
@@ -487,7 +487,8 @@ def ygmain(ygclass, nickserv_password='', gaplimit=6):
         snicker_factory = None
     nodaemon = jm_single().config.getint("DAEMON", "no_daemon")
     daemon = True if nodaemon == 1 else False
-    if jm_single().config.get("BLOCKCHAIN", "network") in ["regtest", "testnet", "signet"]:
+    if jm_single().config.get("BLOCKCHAIN", "network") in [
+            "regtest", "testnet", "signet", "testnet4"]:
         startLogging(sys.stdout)
     start_reactor(jm_single().config.get("DAEMON", "daemon_host"),
                       jm_single().config.getint("DAEMON", "daemon_port"),
diff --git a/src/jmdaemon/irc.py b/src/jmdaemon/irc.py
index 7b090f380..6039158e3 100644
--- a/src/jmdaemon/irc.py
+++ b/src/jmdaemon/irc.py
@@ -47,6 +47,8 @@ def get_config_irc_channel(chan_name, btcnet):
     channel = "#" + chan_name
     if btcnet == "testnet":
         channel += "-test"
+    elif btcnet == "testnet4":
+        channel += "-test4"
     elif btcnet == "signet":
         channel += "-sig"
     return channel