diff --git a/src/miner.h b/src/miner.h
--- a/src/miner.h
+++ b/src/miner.h
@@ -168,7 +168,16 @@
     int lastFewTxs;
 
 public:
-    BlockAssembler(const Config &_config, const CTxMemPool &mempool);
+    struct Options {
+        Options();
+        size_t nBlockMaxSize;
+        CFeeRate blockMinFeeRate;
+    };
+
+    BlockAssembler(const Config &config, const CTxMemPool &mempool);
+    BlockAssembler(const Config &config, const CTxMemPool &mempool,
+                   const Options &options);
+
     /** Construct a new block template with coinbase to scriptPubKeyIn */
     std::unique_ptr<CBlockTemplate>
     CreateNewBlock(const CScript &scriptPubKeyIn);
diff --git a/src/miner.cpp b/src/miner.cpp
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -63,10 +63,7 @@
 
 static uint64_t ComputeMaxGeneratedBlockSize(const Config &config,
                                              const CBlockIndex *pindexPrev) {
-    // Block resource limits
     // If -blockmaxsize is not given, limit to DEFAULT_MAX_GENERATED_BLOCK_SIZE
-    // If only one is given, only restrict the specified resource.
-    // If both are given, restrict both.
     uint64_t nMaxGeneratedBlockSize = DEFAULT_MAX_GENERATED_BLOCK_SIZE;
     if (gArgs.IsArgSet("-blockmaxsize")) {
         nMaxGeneratedBlockSize =
@@ -81,22 +78,41 @@
     return nMaxGeneratedBlockSize;
 }
 
-BlockAssembler::BlockAssembler(const Config &_config, const CTxMemPool &mpool)
+BlockAssembler::Options::Options() {
+    blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE_PER_KB);
+    nBlockMaxSize = DEFAULT_MAX_BLOCK_SIZE;
+}
+
+BlockAssembler::BlockAssembler(const Config &_config, const CTxMemPool &mpool,
+                               const Options &options)
     : config(&_config), mempool(&mpool) {
+    blockMinFeeRate = options.blockMinFeeRate;
+    // Limit size to between 1K and max block size-1K for sanity:
+    nMaxGeneratedBlockSize =
+        std::max(uint64_t(1000), std::min(config->GetMaxBlockSize() - 1000,
+                                          options.nBlockMaxSize));
+}
 
+static BlockAssembler::Options DefaultOptions(const Config &config) {
+    BlockAssembler::Options options;
+    {
+        LOCK(cs_main);
+        options.nBlockMaxSize =
+            ComputeMaxGeneratedBlockSize(config, chainActive.Tip());
+    }
     if (gArgs.IsArgSet("-blockmintxfee")) {
         Amount n = Amount::zero();
         ParseMoney(gArgs.GetArg("-blockmintxfee", ""), n);
-        blockMinFeeRate = CFeeRate(n);
+        options.blockMinFeeRate = CFeeRate(n);
     } else {
-        blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE_PER_KB);
+        options.blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE_PER_KB);
     }
-
-    LOCK(cs_main);
-    nMaxGeneratedBlockSize =
-        ComputeMaxGeneratedBlockSize(*config, chainActive.Tip());
+    return options;
 }
 
+BlockAssembler::BlockAssembler(const Config &_config, const CTxMemPool &mpool)
+    : BlockAssembler(_config, mpool, DefaultOptions(_config)) {}
+
 void BlockAssembler::resetBlock() {
     inBlock.clear();
 
diff --git a/src/test/miner_tests.cpp b/src/test/miner_tests.cpp
--- a/src/test/miner_tests.cpp
+++ b/src/test/miner_tests.cpp
@@ -32,6 +32,15 @@
 
 static CFeeRate blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE_PER_KB);
 
+static BlockAssembler AssemblerForTest(const Config &config,
+                                       const CTxMemPool &mempool) {
+    BlockAssembler::Options options;
+
+    options.nBlockMaxSize = DEFAULT_MAX_BLOCK_SIZE;
+    options.blockMinFeeRate = blockMinFeeRate;
+    return BlockAssembler(config, mempool, options);
+}
+
 static struct {
     uint8_t extranonce;
     uint32_t nonce;
@@ -126,7 +135,7 @@
                                             .FromTx(tx));
 
     std::unique_ptr<CBlockTemplate> pblocktemplate =
-        BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey);
+        AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey);
     BOOST_CHECK(pblocktemplate->block.vtx[1]->GetId() == parentTxId);
     BOOST_CHECK(pblocktemplate->block.vtx[2]->GetId() == highFeeTxId);
     BOOST_CHECK(pblocktemplate->block.vtx[3]->GetId() == mediumFeeTxId);
@@ -149,7 +158,7 @@
     TxId lowFeeTxId = tx.GetId();
     g_mempool.addUnchecked(lowFeeTxId, entry.Fee(feeToUse).FromTx(tx));
     pblocktemplate =
-        BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey);
+        AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey);
     // Verify that the free tx and the low fee tx didn't get selected.
     for (const auto &txn : pblocktemplate->block.vtx) {
         BOOST_CHECK(txn->GetId() != freeTxId);
@@ -166,7 +175,7 @@
     g_mempool.addUnchecked(lowFeeTxId,
                            entry.Fee(feeToUse + 2 * SATOSHI).FromTx(tx));
     pblocktemplate =
-        BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey);
+        AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey);
     BOOST_CHECK(pblocktemplate->block.vtx[4]->GetId() == freeTxId);
     BOOST_CHECK(pblocktemplate->block.vtx[5]->GetId() == lowFeeTxId);
 
@@ -191,7 +200,7 @@
     g_mempool.addUnchecked(
         lowFeeTxId2, entry.Fee(feeToUse).SpendsCoinbase(false).FromTx(tx));
     pblocktemplate =
-        BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey);
+        AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey);
 
     // Verify that this tx isn't selected.
     for (const auto &txn : pblocktemplate->block.vtx) {
@@ -206,7 +215,7 @@
     tx.vout[0].nValue = (100000000 - 10000) * SATOSHI;
     g_mempool.addUnchecked(tx.GetId(), entry.Fee(10000 * SATOSHI).FromTx(tx));
     pblocktemplate =
-        BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey);
+        AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey);
     BOOST_CHECK(pblocktemplate->block.vtx[8]->GetId() == lowFeeTxId2);
 }
 
@@ -221,7 +230,7 @@
                   << OP_CHECKSIG;
 
     std::unique_ptr<CBlockTemplate> pblocktemplate =
-        BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey);
+        AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey);
 
     CBlock *pblock = &pblocktemplate->block;
 
@@ -268,7 +277,7 @@
     // Simple block creation, nothing special yet:
     BOOST_CHECK(
         pblocktemplate =
-            BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey));
+            AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey));
 
     // We can't make transactions until we have inputs. Therefore, load 100
     // blocks :)
@@ -309,7 +318,7 @@
     // Just to make sure we can still make simple blocks.
     BOOST_CHECK(
         pblocktemplate =
-            BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey));
+            AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey));
 
     const Amount BLOCKSUBSIDY = 50 * COIN;
     const Amount LOWFEE = CENT;
@@ -338,7 +347,7 @@
         tx.vin[0].prevout = COutPoint(hash, 0);
     }
     BOOST_CHECK_THROW(
-        BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey),
+        AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey),
         std::runtime_error);
     g_mempool.clear();
 
@@ -360,7 +369,7 @@
     }
     BOOST_CHECK(
         pblocktemplate =
-            BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey));
+            AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey));
     g_mempool.clear();
 
     // block size > limit
@@ -387,14 +396,14 @@
     }
     BOOST_CHECK(
         pblocktemplate =
-            BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey));
+            AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey));
     g_mempool.clear();
 
     // Orphan in mempool, template creation fails.
     hash = tx.GetId();
     g_mempool.addUnchecked(hash, entry.Fee(LOWFEE).Time(GetTime()).FromTx(tx));
     BOOST_CHECK_THROW(
-        BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey),
+        AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey),
         std::runtime_error);
     g_mempool.clear();
 
@@ -418,7 +427,7 @@
         entry.Fee(HIGHERFEE).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));
     BOOST_CHECK(
         pblocktemplate =
-            BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey));
+            AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey));
     g_mempool.clear();
 
     // Coinbase in mempool, template creation fails.
@@ -432,7 +441,7 @@
         hash,
         entry.Fee(LOWFEE).Time(GetTime()).SpendsCoinbase(false).FromTx(tx));
     BOOST_CHECK_THROW(
-        BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey),
+        AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey),
         std::runtime_error);
     g_mempool.clear();
 
@@ -451,7 +460,7 @@
         hash,
         entry.Fee(HIGHFEE).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));
     BOOST_CHECK_THROW(
-        BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey),
+        AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey),
         std::runtime_error);
     g_mempool.clear();
 
@@ -470,7 +479,7 @@
     }
     BOOST_CHECK(
         pblocktemplate =
-            BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey));
+            AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey));
     // Extend to a 210000-long block chain.
     while (chainActive.Tip()->nHeight < 210000) {
         CBlockIndex *prev = chainActive.Tip();
@@ -484,7 +493,7 @@
     }
     BOOST_CHECK(
         pblocktemplate =
-            BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey));
+            AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey));
 
     // Invalid p2sh txn in mempool, template creation fails
     tx.vin[0].prevout = COutPoint(txFirst[0]->GetId(), 0);
@@ -505,7 +514,7 @@
         hash,
         entry.Fee(LOWFEE).Time(GetTime()).SpendsCoinbase(false).FromTx(tx));
     BOOST_CHECK_THROW(
-        BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey),
+        AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey),
         std::runtime_error);
     g_mempool.clear();
 
@@ -676,7 +685,7 @@
     BOOST_CHECK(!TestSequenceLocks(CTransaction(tx), flags));
 
     pblocktemplate =
-        BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey);
+        AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey);
     BOOST_CHECK(pblocktemplate);
 
     // None of the of the absolute height/time locked tx should have made it
@@ -696,7 +705,7 @@
 
     BOOST_CHECK(
         pblocktemplate =
-            BlockAssembler(config, g_mempool).CreateNewBlock(scriptPubKey));
+            AssemblerForTest(config, g_mempool).CreateNewBlock(scriptPubKey));
     BOOST_CHECK_EQUAL(pblocktemplate->block.vtx.size(), 5UL);
 
     chainActive.Tip()->nHeight--;
@@ -713,6 +722,13 @@
 
     BlockAssembler ba(config, g_mempool);
     BOOST_CHECK_EQUAL(ba.GetMaxGeneratedBlockSize(), expected);
+
+    // BlockAssembler with options gives the same result
+    BlockAssembler::Options options;
+    options.nBlockMaxSize = size;
+    options.blockMinFeeRate = blockMinFeeRate;
+    BlockAssembler ba2(config, g_mempool, options);
+    BOOST_CHECK_EQUAL(ba2.GetMaxGeneratedBlockSize(), expected);
 }
 
 BOOST_AUTO_TEST_CASE(BlockAssembler_construction) {