diff --git a/src/miner.cpp b/src/miner.cpp
index d01edd93b5..167e74284c 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -72,43 +72,56 @@ int64_t UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParam
     return nNewTime - nOldTime;
 }
 
-BlockAssembler::BlockAssembler(const CChainParams& _chainparams)
-    : chainparams(_chainparams)
+BlockAssembler::Options::Options() {
+    blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE);
+    nBlockMaxWeight = DEFAULT_BLOCK_MAX_WEIGHT;
+    nBlockMaxSize = DEFAULT_BLOCK_MAX_SIZE;
+}
+
+BlockAssembler::BlockAssembler(const CChainParams& params, const Options& options) : chainparams(params)
+{
+    blockMinFeeRate = options.blockMinFeeRate;
+    // Limit weight to between 4K and MAX_BLOCK_WEIGHT-4K for sanity:
+    nBlockMaxWeight = std::max<size_t>(4000, std::min<size_t>(MAX_BLOCK_WEIGHT - 4000, options.nBlockMaxWeight));
+    // Limit size to between 1K and MAX_BLOCK_SERIALIZED_SIZE-1K for sanity:
+    nBlockMaxSize = std::max<size_t>(1000, std::min<size_t>(MAX_BLOCK_SERIALIZED_SIZE - 1000, options.nBlockMaxSize));
+    // Whether we need to account for byte usage (in addition to weight usage)
+    fNeedSizeAccounting = (nBlockMaxSize < MAX_BLOCK_SERIALIZED_SIZE - 1000);
+}
+
+static BlockAssembler::Options DefaultOptions(const CChainParams& params)
 {
     // Block resource limits
     // If neither -blockmaxsize or -blockmaxweight is given, limit to DEFAULT_BLOCK_MAX_*
     // If only one is given, only restrict the specified resource.
     // If both are given, restrict both.
-    nBlockMaxWeight = DEFAULT_BLOCK_MAX_WEIGHT;
-    nBlockMaxSize = DEFAULT_BLOCK_MAX_SIZE;
+    BlockAssembler::Options options;
+    options.nBlockMaxWeight = DEFAULT_BLOCK_MAX_WEIGHT;
+    options.nBlockMaxSize = DEFAULT_BLOCK_MAX_SIZE;
     bool fWeightSet = false;
     if (IsArgSet("-blockmaxweight")) {
-        nBlockMaxWeight = GetArg("-blockmaxweight", DEFAULT_BLOCK_MAX_WEIGHT);
-        nBlockMaxSize = MAX_BLOCK_SERIALIZED_SIZE;
+        options.nBlockMaxWeight = GetArg("-blockmaxweight", DEFAULT_BLOCK_MAX_WEIGHT);
+        options.nBlockMaxSize = MAX_BLOCK_SERIALIZED_SIZE;
         fWeightSet = true;
     }
     if (IsArgSet("-blockmaxsize")) {
-        nBlockMaxSize = GetArg("-blockmaxsize", DEFAULT_BLOCK_MAX_SIZE);
+        options.nBlockMaxSize = GetArg("-blockmaxsize", DEFAULT_BLOCK_MAX_SIZE);
         if (!fWeightSet) {
-            nBlockMaxWeight = nBlockMaxSize * WITNESS_SCALE_FACTOR;
+            options.nBlockMaxWeight = options.nBlockMaxSize * WITNESS_SCALE_FACTOR;
         }
     }
     if (IsArgSet("-blockmintxfee")) {
         CAmount n = 0;
         ParseMoney(GetArg("-blockmintxfee", ""), n);
-        blockMinFeeRate = CFeeRate(n);
+        options.blockMinFeeRate = CFeeRate(n);
     } else {
-        blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE);
+        options.blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE);
     }
-
-    // Limit weight to between 4K and MAX_BLOCK_WEIGHT-4K for sanity:
-    nBlockMaxWeight = std::max((unsigned int)4000, std::min((unsigned int)(MAX_BLOCK_WEIGHT-4000), nBlockMaxWeight));
-    // Limit size to between 1K and MAX_BLOCK_SERIALIZED_SIZE-1K for sanity:
-    nBlockMaxSize = std::max((unsigned int)1000, std::min((unsigned int)(MAX_BLOCK_SERIALIZED_SIZE-1000), nBlockMaxSize));
-    // Whether we need to account for byte usage (in addition to weight usage)
-    fNeedSizeAccounting = (nBlockMaxSize < MAX_BLOCK_SERIALIZED_SIZE-1000);
+    return options;
 }
 
+BlockAssembler::BlockAssembler(const CChainParams& params) : BlockAssembler(params, DefaultOptions(params)) {}
+
 void BlockAssembler::resetBlock()
 {
     inBlock.clear();
diff --git a/src/miner.h b/src/miner.h
index 3ba92b16b8..fc2526ff5a 100644
--- a/src/miner.h
+++ b/src/miner.h
@@ -163,7 +163,16 @@ private:
     bool blockFinished;
 
 public:
-    BlockAssembler(const CChainParams& chainparams);
+    struct Options {
+        Options();
+        size_t nBlockMaxWeight;
+        size_t nBlockMaxSize;
+        CFeeRate blockMinFeeRate;
+    };
+
+    BlockAssembler(const CChainParams& params);
+    BlockAssembler(const CChainParams& params, const Options& options);
+
     /** Construct a new block template with coinbase to scriptPubKeyIn */
     std::unique_ptr<CBlockTemplate> CreateNewBlock(const CScript& scriptPubKeyIn);