diff --git a/doc/release-notes-6189.md b/doc/release-notes-6189.md
new file mode 100644
index 0000000000..be8815c960
--- /dev/null
+++ b/doc/release-notes-6189.md
@@ -0,0 +1,5 @@
+Tests
+-----
+
+- For the `regtest` network the BIP 66 (DERSIG) activation height was changed
+  from 1251 to 102. (dash#6189)
diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index d946b2d84b..90e652a839 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -797,7 +797,7 @@ public:
         consensus.BIP34Height = 500; // BIP34 activated on regtest (Used in functional tests)
         consensus.BIP34Hash = uint256();
         consensus.BIP65Height = 1351; // BIP65 activated on regtest (Used in functional tests)
-        consensus.BIP66Height = 1251; // BIP66 activated on regtest (Used in functional tests)
+        consensus.BIP66Height = 102; // BIP66 activated on regtest (Block at height 101 and earlier not enforced for testing purposes)
         consensus.BIP147Height = 432; // BIP147 activated on regtest (Used in functional tests)
         consensus.CSVHeight = 432; // CSV activated on regtest (Used in rpc activation tests)
         consensus.DIP0001Height = 2000;
diff --git a/test/functional/feature_dersig.py b/test/functional/feature_dersig.py
index 6e3a49df3e..597bce5a7e 100755
--- a/test/functional/feature_dersig.py
+++ b/test/functional/feature_dersig.py
@@ -4,10 +4,11 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Test BIP66 (DER SIG).
 
-Test that the DERSIG soft-fork activates at (regtest) height 1251.
+Test the DERSIG soft-fork activation on regtest.
 """
 
 from test_framework.blocktools import (
+    DERSIG_HEIGHT,
     create_block,
     create_coinbase,
 )
@@ -24,8 +25,6 @@ from test_framework.wallet import (
     MiniWalletMode,
 )
 
-DERSIG_HEIGHT = 1251
-
 
 # A canonical signature consists of:
 # <30> <total len> <02> <len R> <R> <02> <len S> <S> <hashtype>
@@ -88,8 +87,10 @@ class BIP66Test(BitcoinTestFramework):
         block.rehash()
         block.solve()
 
+        assert_equal(self.nodes[0].getblockcount(), DERSIG_HEIGHT - 2)
         self.test_dersig_info(is_active=False)  # Not active as of current tip and next block does not need to obey rules
         peer.send_and_ping(msg_block(block))
+        assert_equal(self.nodes[0].getblockcount(), DERSIG_HEIGHT - 1)
         self.test_dersig_info(is_active=True)  # Not active as of current tip, but next block must obey rules
         assert_equal(self.nodes[0].getbestblockhash(), block.hash)
 
diff --git a/test/functional/rpc_blockchain.py b/test/functional/rpc_blockchain.py
index 9c4eab3a37..1e6b23d354 100755
--- a/test/functional/rpc_blockchain.py
+++ b/test/functional/rpc_blockchain.py
@@ -27,6 +27,7 @@ import subprocess
 
 from test_framework.address import ADDRESS_BCRT1_P2SH_OP_TRUE
 from test_framework.blocktools import (
+    DERSIG_HEIGHT,
     create_block,
     create_coinbase,
     TIME_GENESIS_BLOCK,
@@ -143,7 +144,7 @@ class BlockchainTest(BitcoinTestFramework):
         assert_greater_than(res['size_on_disk'], 0)
         assert_equal(res['softforks'], {
             'bip34': {'type': 'buried', 'active': False, 'height': 500},
-            'bip66': {'type': 'buried', 'active': False, 'height': 1251},
+            'bip66': {'type': 'buried', 'active': True, 'height': DERSIG_HEIGHT},
             'bip65': {'type': 'buried', 'active': False, 'height': 1351},
             'bip147': { 'type': 'buried', 'active': False, 'height': 432},
             'csv': {'type': 'buried', 'active': False, 'height': 432},
diff --git a/test/functional/test_framework/blocktools.py b/test/functional/test_framework/blocktools.py
index 423ffbeb49..ae909a9ee0 100644
--- a/test/functional/test_framework/blocktools.py
+++ b/test/functional/test_framework/blocktools.py
@@ -36,6 +36,7 @@ TIME_GENESIS_BLOCK = 1417713337
 COINBASE_MATURITY = 100
 
 # Soft-fork activation heights
+DERSIG_HEIGHT = 102  # BIP 66
 CLTV_HEIGHT = 1351
 CSV_ACTIVATION_HEIGHT = 432