diff --git a/src/policy/policy.h b/src/policy/policy.h
--- a/src/policy/policy.h
+++ b/src/policy/policy.h
@@ -22,7 +22,7 @@
 static const uint64_t DEFAULT_BLOCK_PRIORITY_PERCENTAGE = 5;
 /** Default for -blockmintxfee, which sets the minimum feerate for a transaction
  * in blocks created by mining code **/
-static const Amount DEFAULT_BLOCK_MIN_TX_FEE(1000);
+static const Amount DEFAULT_BLOCK_MIN_TX_FEE(0);
 /** The maximum size for transactions we're willing to relay/mine */
 static const unsigned int MAX_STANDARD_TX_SIZE = 100000;
 /** Maximum number of signature check operations in an IsStandard() P2SH script
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
@@ -3,7 +3,6 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include "miner.h"
-
 #include "chainparams.h"
 #include "coins.h"
 #include "config.h"
@@ -89,6 +88,10 @@
     // these 3 tests assume blockprioritypercentage is 0.
     config.SetBlockPriorityPercentage(0);
 
+    // the following tests assume that minimum fee rate is 1000 satoshi per kB.
+    ForceSetArg("-blockmintxfee", std::to_string(1000));
+    blockMinFeeRate = CFeeRate(1000);
+
     // Test that a medium fee transaction will be selected after a higher fee
     // rate package with a low fee rate parent.
     CMutableTransaction tx;
diff --git a/src/validation.h b/src/validation.h
--- a/src/validation.h
+++ b/src/validation.h
@@ -56,7 +56,7 @@
 /** Default for DEFAULT_WHITELISTFORCERELAY. */
 static const bool DEFAULT_WHITELISTFORCERELAY = true;
 /** Default for -minrelaytxfee, minimum relay fee for transactions */
-static const Amount DEFAULT_MIN_RELAY_TX_FEE(1000);
+static const Amount DEFAULT_MIN_RELAY_TX_FEE(0);
 //! -maxtxfee default
 static const Amount DEFAULT_TRANSACTION_MAXFEE(COIN / 10);
 //! Discourage users to set fees higher than this amount (in satoshis) per kB
@@ -140,7 +140,7 @@
  */
 static const int64_t BLOCK_DOWNLOAD_TIMEOUT_PER_PEER = 500000;
 
-static const unsigned int DEFAULT_LIMITFREERELAY = 0;
+static const unsigned int DEFAULT_LIMITFREERELAY = 20;
 static const bool DEFAULT_RELAYPRIORITY = true;
 static const int64_t DEFAULT_MAX_TIP_AGE = 24 * 60 * 60;
 /** Maximum age of our tip in seconds for us to be considered current for fee