diff --git a/lib/contracts/deploy.js b/lib/contracts/deploy.js
index be4207d42..85e1b466d 100644
--- a/lib/contracts/deploy.js
+++ b/lib/contracts/deploy.js
@@ -44,10 +44,9 @@ class Deploy {
       return callback();
     }
 
+    realArgs = self.determineArguments(params || contract.args);
+
     if (contract.address !== undefined) {
-
-      realArgs = self.determineArguments(params || contract.args);
-
       contract.deployedAddress = contract.address;
       self.deployTracker.trackContract(contract.className, contract.realRuntimeBytecode, realArgs, contract.address);
       self.deployTracker.save();
@@ -55,7 +54,7 @@ class Deploy {
       return callback();
     }
 
-    let trackedContract = self.deployTracker.getContract(contract.className, contract.realRuntimeBytecode, contract.args);
+    let trackedContract = self.deployTracker.getContract(contract.className, contract.realRuntimeBytecode, realArgs);
 
     if (trackedContract && this.web3.eth.getCode(trackedContract.address) !== "0x") {
       self.logger.info(contract.className.bold.cyan + " already deployed at ".green + trackedContract.address.bold.cyan);
@@ -88,8 +87,8 @@ class Deploy {
         if (contract.onDeploy !== undefined) {
           self.logger.info('executing onDeploy commands');
 
-          let cmds = "";
-          cmds += codeGenerator.generateContractCode(contract);
+          let contractCode = codeGenerator.generateContractCode(contract);
+          RunCode.doEval(contractCode, self.web3);
 
           let withErrors = false;
           let regex = /\$\w+/g;
@@ -128,9 +127,18 @@ class Deploy {
             return callback(new Error("error running onDeploy"));
           }
 
-          cmds += onDeployCode.join(';\n');
-
-          RunCode.doEval(cmds, self.web3);
+          // TODO: convert to for to avoid repeated callback
+          for(let cmd of onDeployCode) {
+            self.logger.info("executing: " + cmd);
+            try {
+              RunCode.doEval(cmd, self.web3);
+            } catch(e) {
+              if (e.message.indexOf("invalid opcode") >= 0) {
+                self.logger.error('the transaction was rejected; this usually happens due to a throw or a require, it can also happen due to an invalid operation');
+              }
+              return callback(new Error(e));
+            }
+          }
         }
 
         callback();
diff --git a/lib/contracts/deploy_tracker.js b/lib/contracts/deploy_tracker.js
index 38874c115..96426502d 100644
--- a/lib/contracts/deploy_tracker.js
+++ b/lib/contracts/deploy_tracker.js
@@ -59,4 +59,3 @@ class DeployTracker {
 }
 
 module.exports = DeployTracker;
-