diff --git a/lib/modules/blockchain_process/blockchain.js b/lib/modules/blockchain_process/blockchain.js
index 90e4a1619..f5c3f85d5 100644
--- a/lib/modules/blockchain_process/blockchain.js
+++ b/lib/modules/blockchain_process/blockchain.js
@@ -231,7 +231,7 @@ Blockchain.prototype.readyCallback = function() {
 
   if (this.config.mineWhenNeeded && !this.isDev) {
     const GethMiner = require('./miner');
-    this.miner = new GethMiner();
+    this.miner = new GethMiner({datadir: this.blockchainConfig.datadir});
   }
 };
 
@@ -316,7 +316,7 @@ Blockchain.prototype.initChainAndGetAddress = function(callback) {
 };
 
 var BlockchainClient = function(blockchainConfig, client, env, onReadyCallback, onExitCallback) {
-  const isDev = blockchainConfig.isDev || blockchainConfig.default;
+  const isDev = Boolean(blockchainConfig.isDev);
   // TODO add other clients at some point
   if (client === 'geth') {
     return new Blockchain({blockchainConfig, client: GethCommands, env, isDev, onReadyCallback, onExitCallback});
diff --git a/lib/modules/blockchain_process/miner.js b/lib/modules/blockchain_process/miner.js
index 16590a10d..79f132b83 100644
--- a/lib/modules/blockchain_process/miner.js
+++ b/lib/modules/blockchain_process/miner.js
@@ -13,11 +13,12 @@ const getChanges = 'eth_getFilterChanges';
 const getBlockCount = 'eth_getBlockTransactionCountByNumber';
 
 class GethMiner {
-  constructor() {
+  constructor(options) {
     const self = this;
     // TODO: Find a way to load mining config from YML.
     // In the meantime, just set an empty config object
     this.config = {};
+    this.datadir = options.datadir;
     self.interval = null;
     self.callback = null;
     self.started = null;