diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 480a02f24b..dd53f58232 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -436,9 +436,10 @@ class CCustomParams : public CRegTestParams {
         std::vector<unsigned char> man_bytes = ParseHex(gArgs.GetArg("-con_mandatorycoinbase", ""));
         consensus.mandatory_coinbase_destination = CScript(man_bytes.begin(), man_bytes.end()); // Blank script allows any coinbase destination
 
-        // Block signing encumberance script
-        std::vector<unsigned char> sign_bytes = ParseHex(gArgs.GetArg("-signblockscript", ""));
+        // Block signing encumberance script, default of 51 aka OP_TRUE
+        std::vector<unsigned char> sign_bytes = ParseHex(gArgs.GetArg("-signblockscript", "51"));
         consensus.signblockscript = CScript(sign_bytes.begin(), sign_bytes.end());
+        g_signed_blocks = !sign_bytes.empty();
 
         // Custom chains connect coinbase outputs to db by default
         consensus.connect_genesis_outputs = gArgs.GetArg("-con_connect_coinbase", true);
diff --git a/src/consensus/params.h b/src/consensus/params.h
index e82c134cc8..d90901faf4 100644
--- a/src/consensus/params.h
+++ b/src/consensus/params.h
@@ -84,6 +84,7 @@ struct Params {
     CAmount genesis_subsidy;
     bool connect_genesis_outputs;
     CScript signblockscript;
+    // g_signed_blocks - Whether blocks are signed or not, get around circular dep
 };
 } // namespace Consensus
 
diff --git a/src/primitives/block.cpp b/src/primitives/block.cpp
index ee41cc88d6..01d20719d4 100644
--- a/src/primitives/block.cpp
+++ b/src/primitives/block.cpp
@@ -10,6 +10,8 @@
 #include <utilstrencodings.h>
 #include <crypto/common.h>
 
+bool g_signed_blocks = false;
+
 std::string CProof::ToString() const
 {
     return strprintf("CProof(challenge=%s, solution=%s)",
diff --git a/src/primitives/block.h b/src/primitives/block.h
index 2c37a718a5..5c182d426f 100644
--- a/src/primitives/block.h
+++ b/src/primitives/block.h
@@ -11,6 +11,8 @@
 #include <serialize.h>
 #include <uint256.h>
 
+extern bool g_signed_blocks;
+
 class CProof
 {
 public:
@@ -79,7 +81,7 @@ public:
         READWRITE(hashPrevBlock);
         READWRITE(hashMerkleRoot);
         READWRITE(nTime);
-        if (false) {
+        if (g_signed_blocks) {
             READWRITE(proof);
         } else {
             READWRITE(nBits);
@@ -100,7 +102,7 @@ public:
 
     bool IsNull() const
     {
-        if (false) {
+        if (g_signed_blocks) {
             return proof.IsNull();
         } else {
             return (nBits == 0);
diff --git a/test/bitcoin_functional/functional/test_framework/util.py b/test/bitcoin_functional/functional/test_framework/util.py
index e081aab825..f8689b40c5 100644
--- a/test/bitcoin_functional/functional/test_framework/util.py
+++ b/test/bitcoin_functional/functional/test_framework/util.py
@@ -307,6 +307,7 @@ def initialize_datadir(dirname, n, chain):
         f.write("printtoconsole=0\n")
         f.write("con_blocksubsidy=5000000000\n")
         f.write("con_connect_coinbase=0\n")
+        f.write("signblockscript=0\n")
         os.makedirs(os.path.join(datadir, 'stderr'), exist_ok=True)
         os.makedirs(os.path.join(datadir, 'stdout'), exist_ok=True)
     return datadir