diff --git a/contrib/seeds/nodes_main.txt b/contrib/seeds/nodes_main.txt
index ad46cd07a4..234ea6320a 100644
--- a/contrib/seeds/nodes_main.txt
+++ b/contrib/seeds/nodes_main.txt
@@ -36,6 +36,10 @@
 [2a02:c207:2110:9259::1]
 [2a10:3781:525:1::210]
 [2a10:3781:525:1::201]
+[2a10:3781:525:1::211]
+[2a10:3781:525:1::212]
+[2a10:3781:525:1::213]
+[2a10:3781:525:1::215]
 [2a10:3781:525:6::10]
 [2a10:3781:525:6::11]
 [2602:fec3:2:10::9:91]
diff --git a/contrib/seeds/nodes_test.txt b/contrib/seeds/nodes_test.txt
index 8772f2a792..849dd7bb12 100644
--- a/contrib/seeds/nodes_test.txt
+++ b/contrib/seeds/nodes_test.txt
@@ -5,7 +5,6 @@
 167.86.117.144
 167.86.117.143
 45.137.91.173
-45.137.91.173
 5.189.160.139
 81.0.246.79
 5.189.159.220
@@ -27,8 +26,12 @@
 [2a02:c207:2110:9257::1]
 [2a02:c204:2110:9258::1]
 [2a02:c207:2110:9259::1]
-[2a10:3781:525:1::210]
 [2a10:3781:525:1::201]
+[2a10:3781:525:1::210]
+[2a10:3781:525:1::211]
+[2a10:3781:525:1::212]
+[2a10:3781:525:1::213]
+[2a10:3781:525:1::215]
 [2a10:3781:525:6::10]
 [2a10:3781:525:6::11]
 
diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 30df2166f6..a65dae2fcc 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -117,7 +117,7 @@ class CMainParams : public CChainParams {
         consensus.nCoinbaseMaturity = 500;
 
         // The best chain should have at least this much work.
-        consensus.nMinimumChainWork = uint256S("0x000000000000000000000000000000000000000000000416ebe78f593ec11fb2"); // block 4791500
+        consensus.nMinimumChainWork = uint256S("0x00000000000000000000000000000000000000000000042bc25fcf69bab7b312"); // block 4938940
 
         /**
          * The message start string is designed to be unlikely to occur in normal data.
@@ -164,9 +164,10 @@ class CMainParams : public CChainParams {
                     (254348, uint256S("0x9bf8d9bd757d3ef23d5906d70567e5f0da93f1e0376588c8d421a95e2421838b"))  // minor network split
                     (319002, uint256S("0x0011494d03b2cdf1ecfc8b0818f1e0ef7ee1d9e9b3d1279c10d35456bc3899ef"))  // hardfork
                     (872456, uint256S("0xe4fd321ced1de06213d2e246b150b4bfd8c4aa0989965dce88f2a58668c64860"))  // hardfork
-                    (4232630, uint256S("0xae0c2a9bd13746e2887ca57bf1046b3c787a5ed1068fd1633a3575f08ee291fc")), // start devfund
-                    1668631296, // * UNIX timestamp of last checkpoint block
-                    13562393,    // * total number of transactions between genesis and last checkpoint
+                    (4232630, uint256S("0xae0c2a9bd13746e2887ca57bf1046b3c787a5ed1068fd1633a3575f08ee291fc")) // start devfund
+                    (4908715, uint256S("0x6f8e37e21aa2fba3f8e2d6825cb825ca290e9367ed08b8c30943bc16efcba119")), // PoS v3.1 hardfork
+                    1713938480, // * UNIX timestamp of last checkpoint block
+                    15170003,    // * total number of transactions between genesis and last checkpoint
                                 //   (the tx=... number in the SetBestChain debug.log lines)
                     3500.0      // * estimated number of transactions per day after checkpoint
         };
@@ -220,7 +221,7 @@ class CTestNetParams : public CChainParams {
         nDefaultPort = 25714;
 
         // The best chain should have at least this much work.
-        consensus.nMinimumChainWork = uint256S("0x0000000000000000000000000000000000000000000000478d1e3e759bd0f7e2"); // block 1720482  
+        consensus.nMinimumChainWork = uint256S("0x00000000000000000000000000000000000000000000004ef99ad4b35ad0930a"); // block 1866885  
 
         nPruneAfterHeight = 1000;
 
@@ -249,10 +250,11 @@ class CTestNetParams : public CChainParams {
         checkpointData = (CCheckpointData) {
             boost::assign::map_list_of
             (  90235, uint256S("0x567898e79184dc2f7dc3a661f794f28566e4b856d70180914f7371b1b3cc82d8"))  //initial snapshot
+            (1320664, uint256S("0x64fa6a5414c6797629d34ef150c46486a5e1d49d2bceb87d6da14a501f838afd"))  //PoS v3.1 hardfork 
             (1415393, uint256S("0x5d5c42500cc6057533e249ba9eeb9b5e998aff30468c904bc267ec9bccbc8b39")), //start devfund
             1685643568,
-            70100,
-            2.0
+            280130,
+            3500.0
         };
 
         // A vector of p2sh addresses
diff --git a/src/chainparamsseeds.h b/src/chainparamsseeds.h
index 48f0bba5e6..9c7e5d561a 100644
--- a/src/chainparamsseeds.h
+++ b/src/chainparamsseeds.h
@@ -40,6 +40,10 @@ static SeedSpec6 pnSeed6_main[] = {
     {{0x2a,0x02,0xc2,0x07,0x21,0x10,0x92,0x59,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01}, 15714},
     {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x10}, 15714},
     {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x01}, 15714},
+    {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x11}, 15714},
+    {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x12}, 15714},
+    {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x13}, 15714},
+    {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x15}, 15714},
     {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x06,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x10}, 15714},
     {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x06,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x11}, 15714},
     {{0x26,0x02,0xfe,0xc3,0x00,0x02,0x00,0x10,0x00,0x00,0x00,0x00,0x00,0x09,0x00,0x91}, 15714},
@@ -56,7 +60,6 @@ static SeedSpec6 pnSeed6_test[] = {
     {{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xff,0xff,0xa7,0x56,0x75,0x90}, 25714},
     {{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xff,0xff,0xa7,0x56,0x75,0x8f}, 25714},
     {{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xff,0xff,0x2d,0x89,0x5b,0xad}, 25714},
-    {{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xff,0xff,0x2d,0x89,0x5b,0xad}, 25714},
     {{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xff,0xff,0x05,0xbd,0xa0,0x8b}, 25714},
     {{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xff,0xff,0x51,0x00,0xf6,0x4f}, 25714},
     {{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xff,0xff,0x05,0xbd,0x9f,0xdc}, 25714},
@@ -76,7 +79,12 @@ static SeedSpec6 pnSeed6_test[] = {
     {{0x2a,0x02,0xc2,0x07,0x21,0x10,0x92,0x57,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01}, 25714},
     {{0x2a,0x02,0xc2,0x04,0x21,0x10,0x92,0x58,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01}, 25714},
     {{0x2a,0x02,0xc2,0x07,0x21,0x10,0x92,0x59,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01}, 25714},
+    {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x01}, 25714},
     {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x10}, 25714},
+    {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x11}, 25714},
+    {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x12}, 25714},
+    {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x13}, 25714},
+    {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x15}, 25714},
     {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x01}, 25714},
     {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x06,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x10}, 25714},
     {{0x2a,0x10,0x37,0x81,0x05,0x25,0x00,0x06,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x11}, 25714},