diff --git a/contrib/devtools/generate-bestchainparams.sh b/contrib/devtools/generate-bestchainparams.sh
new file mode 100755
--- /dev/null
+++ b/contrib/devtools/generate-bestchainparams.sh
@@ -0,0 +1,90 @@
+#!/bin/bash
+
+# set -e            Script exits immediately when a command fails.
+# set -u            Treats unset variables as a failure.
+set -eu
+
+help_message() {
+  echo "Generate a chainparams chain source file."
+  echo "Usage: $0 <options> > chainparamsbestchainmainnet.h"
+  echo "-b, --blockhash <hash>    The block hash to update defaultAssumeValid to."
+  echo "-c, --chainwork <hex>     The chainwork to update nMinimumChainWork to."
+  echo "-t, --testnet             If set, testnet chainparams will be updated instead of mainnet chainparams."
+}
+
+BLOCK_HASH=""
+CHAIN_WORK=""
+CHAIN="MainNet"
+
+# Parse command line arguments
+while [[ $# -gt 0 ]]; do
+case "$1" in
+  -b|--blockhash)
+    BLOCK_HASH="$2"
+    shift # shift past argument
+    shift # shift past value
+    ;;
+  -c|--chainwork)
+    CHAIN_WORK="$2"
+    shift # shift past argument
+    shift # shift past value
+    ;;
+  -h|--help)
+    help_message
+    exit 0
+    ;;
+  -t|--testnet)
+    CHAIN="TestNet"
+    shift # shift past argument
+    ;;
+  *)
+    echo "Unknown argument: $1"
+    help_message
+    exit 1
+    ;;
+esac
+done
+
+if [ -z "$BLOCK_HASH" ]; then
+  echo "Block hash is not set."
+  echo ""
+  help_message
+  exit 1
+fi
+if [[ ! "$BLOCK_HASH" =~ ^[0-9a-z]{64}$ ]]; then
+  echo "Block hash is not a valid block hash."
+  exit 1
+fi
+
+if [ -z "$CHAIN_WORK" ]; then
+  echo "Chain work is not set."
+  echo ""
+  help_message
+  exit 1
+fi
+if [[ ! "$CHAIN_WORK" =~ ^[0-9a-z]{64}$ ]]; then
+  echo "Chain work is not a valid uint256 hex value."
+  exit 1
+fi
+
+echo "// Copyright (c) 2019 The Bitcoin developers"
+echo "// Distributed under the MIT software license, see the accompanying"
+echo "// file COPYING or http://www.opensource.org/licenses/mit-license.php."
+echo ""
+echo "// This file is autogenerated. See /contrib/devtools/generate-chainparams.sh"
+echo ""
+echo "#ifndef BITCOIN_CHAINPARAMSBESTCHAIN${CHAIN^^}_H"
+echo "#define BITCOIN_CHAINPARAMSBESTCHAIN${CHAIN^^}_H"
+echo ""
+echo "#include <uint256.h>"
+echo ""
+echo "static inline uint256 Get${CHAIN}MinimumChainWork() {"
+echo "    return uint256S("
+echo "        \"${CHAIN_WORK}\");"
+echo "};"
+echo ""
+echo "static inline uint256 Get${CHAIN}DefaultAssumeValid() {"
+echo "    return uint256S("
+echo "        \"${BLOCK_HASH}\");"
+echo "};"
+echo "#endif // BITCOIN_CHAINPARAMSBESTCHAIN${CHAIN^^}_H"
diff --git a/src/Makefile.am b/src/Makefile.am
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -117,6 +117,8 @@
   chain.h \
   chainparams.h \
   chainparamsbase.h \
+  chainparamsbestchainmainnet.h \
+  chainparamsbestchaintestnet.h \
   chainparamsseeds.h \
   checkpoints.h \
   checkqueue.h \
diff --git a/src/chainparams.cpp b/src/chainparams.cpp
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -5,6 +5,8 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <chainparams.h>
+#include <chainparamsbestchainmainnet.h>
+#include <chainparamsbestchaintestnet.h>
 
 #include <chainparamsseeds.h>
 #include <consensus/merkle.h>
@@ -104,13 +106,11 @@
         consensus.fPowNoRetargeting = false;
 
         // The best chain should have at least this much work.
-        consensus.nMinimumChainWork = uint256S(
-            "000000000000000000000000000000000000000000f22fbd89943b5f5104e4ec");
+        consensus.nMinimumChainWork = GetMainNetMinimumChainWork();
 
         // By default assume that the signatures in ancestors of this block are
         // valid.
-        consensus.defaultAssumeValid = uint256S(
-            "00000000000000000401095ca2933cc4729484965e66e6a9f8e937070cc8e971");
+        consensus.defaultAssumeValid = GetMainNetDefaultAssumeValid();
 
         // August 1, 2017 hard fork
         consensus.uahfHeight = 478558;
@@ -269,13 +269,11 @@
         consensus.fPowNoRetargeting = false;
 
         // The best chain should have at least this much work.
-        consensus.nMinimumChainWork = uint256S(
-            "00000000000000000000000000000000000000000000004f587a0e52b7984751");
+        consensus.nMinimumChainWork = GetTestNetMinimumChainWork();
 
         // By default assume that the signatures in ancestors of this block are
         // valid.
-        consensus.defaultAssumeValid = uint256S(
-            "00000000001b618c015c41cc218a60a5a94bc42e16e30f1426cfc138615201c3");
+        consensus.defaultAssumeValid = GetTestNetDefaultAssumeValid();
 
         // August 1, 2017 hard fork
         consensus.uahfHeight = 1155875;
diff --git a/src/chainparamsbestchainmainnet.h b/src/chainparamsbestchainmainnet.h
new file mode 100644
--- /dev/null
+++ b/src/chainparamsbestchainmainnet.h
@@ -0,0 +1,21 @@
+// Copyright (c) 2019 The Bitcoin developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+// This file is autogenerated. See /contrib/devtools/generate-chainparams.sh
+
+#ifndef BITCOIN_CHAINPARAMSBESTCHAINMAINNET_H
+#define BITCOIN_CHAINPARAMSBESTCHAINMAINNET_H
+
+#include <uint256.h>
+
+static inline uint256 GetMainNetMinimumChainWork() {
+    return uint256S(
+        "000000000000000000000000000000000000000000f22fbd89943b5f5104e4ec");
+};
+
+static inline uint256 GetMainNetDefaultAssumeValid() {
+    return uint256S(
+        "00000000000000000401095ca2933cc4729484965e66e6a9f8e937070cc8e971");
+};
+#endif // BITCOIN_CHAINPARAMSBESTCHAINMAINNET_H
diff --git a/src/chainparamsbestchaintestnet.h b/src/chainparamsbestchaintestnet.h
new file mode 100644
--- /dev/null
+++ b/src/chainparamsbestchaintestnet.h
@@ -0,0 +1,21 @@
+// Copyright (c) 2019 The Bitcoin developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+// This file is autogenerated. See /contrib/devtools/generate-chainparams.sh
+
+#ifndef BITCOIN_CHAINPARAMSBESTCHAINTESTNET_H
+#define BITCOIN_CHAINPARAMSBESTCHAINTESTNET_H
+
+#include <uint256.h>
+
+static inline uint256 GetTestNetMinimumChainWork() {
+    return uint256S(
+        "00000000000000000000000000000000000000000000004f587a0e52b7984751");
+};
+
+static inline uint256 GetTestNetDefaultAssumeValid() {
+    return uint256S(
+        "00000000001b618c015c41cc218a60a5a94bc42e16e30f1426cfc138615201c3");
+};
+#endif // BITCOIN_CHAINPARAMSBESTCHAINTESTNET_H