I have created a ProductFactory contract which creates instances of another Product contract. Now I change code in the Product contract which is imported into the ProductFactory and run

truffle migrate

When I create a new Product instance using ProductFactory the new Product does not reflect changes (new methods, new variables) in the Product contract. The migration file only deploys the ProductFactory like below:

 var ProductFactory = artifacts.require("./ProductFactory.sol");
    module.exports = function(deployer) {
      deployer.deploy(ProductFactory, {gas:4555000});

What should I do to get the Product contract code updated? Do I need to deploy the Product contract also separately?

2 Answers 2


you have to re-deploy the modified version of your contract after each change. You can do that by using the --reset flag with your migrate/deploy command, e.g. truffle migrate --reset


This is how it worked. I was modifying the Product contract but not the ProductFactory which referenced the Product. I had not deployed the Product Contract separately. And the truffle migration does not redeploy only the dependency in such a case. (I guess thats how solidity is) As a workaround I added a variable like below to ProductFactory

uint256 public version = 10;

Now everytime I make a change to Product I increment this value in ProductFactory and the changes are updated and redployed.

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