A contractor signed a contract to construct a building for an owner. Later during a conversation between the owner and the contractor, the owner agreed to be responsible for providing the bricks to be used in construction. This agreement was not written into the contract which of the following statements is true about this situation?

A contractor signed a contract to construct a building for an owner. Later during a conversation between the owner and the contractor, the owner agreed to be responsible for providing the bricks to be used in construction. This agreement was not written into the contract which of the following statements is true about this situation?