diff --git a/bitcoin/chainparams.c b/bitcoin/chainparams.c
index d26e77910..572f8b167 100644
--- a/bitcoin/chainparams.c
+++ b/bitcoin/chainparams.c
@@ -137,6 +137,32 @@ const struct chainparams networks[] = {
      .bip32_key_version = {.bip32_pubkey_version = BIP32_VER_TEST_PUBLIC,
 			   .bip32_privkey_version = BIP32_VER_TEST_PRIVATE},
      .is_elements = false},
+    {.network_name = "testnet4",
+     .onchain_hrp = "tb",
+     .lightning_hrp = "tb",
+     .bip70_name = "testnet4",
+     // 00000000da84f2bafbbc53dee25a72ae507ff4914b867c565be350b0da8bf043
+     .genesis_blockhash = {{{.u.u8 = {0x43, 0xf0, 0x8b, 0xda, 0xb0, 0x50, 0xe3,
+				      0x5b, 0x56, 0x7c, 0x86, 0x4b, 0x91, 0xf4,
+				      0x7f, 0x50, 0xae, 0x72, 0x5a, 0xe2, 0xde,
+				      0x53, 0xbc, 0xfb, 0xba, 0xf2, 0x84, 0xda,
+				      0x00, 0x00, 0x00, 0x00}}}},
+     .rpc_port = 48332,
+     .ln_port = 49735,
+     .cli = "bitcoin-cli",
+     .cli_args = "-testnet4",
+     .cli_min_supported_version = 150000,
+     .dust_limit = { 546 },
+     .max_funding = AMOUNT_SAT_INIT((1 << 24) - 1),
+     .max_payment = AMOUNT_MSAT_INIT(0xFFFFFFFFULL),
+     .max_supply = AMOUNT_SAT_INIT(2100000000000000),
+     .p2pkh_version = 111,
+     .p2sh_version = 196,
+     .testnet = true,
+     .fee_asset_tag = NULL,
+     .bip32_key_version = {.bip32_pubkey_version = BIP32_VER_TEST_PUBLIC,
+			   .bip32_privkey_version = BIP32_VER_TEST_PRIVATE},
+     .is_elements = false},
     {.network_name = "litecoin",
      .onchain_hrp = "ltc",
      .lightning_hrp = "ltc",
diff --git a/common/configdir.c b/common/configdir.c
index c6ac3fdcf..1873074f6 100644
--- a/common/configdir.c
+++ b/common/configdir.c
@@ -336,6 +336,9 @@ struct configvar **initial_config_opts(const tal_t *ctx,
 	opt_register_early_noarg("--testnet",
 				 opt_set_specific_network, "testnet",
 				 "Alias for --network=testnet");
+	opt_register_early_noarg("--testnet4",
+				 opt_set_specific_network, "testnet4",
+				 "Alias for --network=testnet4");
 	opt_register_early_noarg("--signet",
 				 opt_set_specific_network, "signet",
 				 "Alias for --network=signet");
diff --git a/common/json_param.c b/common/json_param.c
index 413814423..b95952dd4 100644
--- a/common/json_param.c
+++ b/common/json_param.c
@@ -775,11 +775,11 @@ struct command_result *param_secrets_array(struct command *cmd,
 
 /**
  * segwit_addr_net_decode - Try to decode a Bech32(m) address and detect
- * testnet/mainnet/regtest/signet
+ * testnet/mainnet/regtest/signet/testnet4
  *
  * This processes the address and returns a string if it is a Bech32
  * address specified by BIP173 or Bech32m as by BIP350. The string is
- * set whether it is testnet or signet (both "tb"),  mainnet ("bc"),
+ * set whether it is testnet/testnet4/signet ("tb"),  mainnet ("bc"),
  * regtest ("bcrt"). It does not check witness version and program size
  * restrictions.
  *