diff --git a/contracts/common/basic.sol b/contracts/mainnet/common/basic.sol
similarity index 100%
rename from contracts/common/basic.sol
rename to contracts/mainnet/common/basic.sol
diff --git a/contracts/common/interfaces.sol b/contracts/mainnet/common/interfaces.sol
similarity index 100%
rename from contracts/common/interfaces.sol
rename to contracts/mainnet/common/interfaces.sol
diff --git a/contracts/common/math.sol b/contracts/mainnet/common/math.sol
similarity index 100%
rename from contracts/common/math.sol
rename to contracts/mainnet/common/math.sol
diff --git a/contracts/common/stores.sol b/contracts/mainnet/common/stores.sol
similarity index 100%
rename from contracts/common/stores.sol
rename to contracts/mainnet/common/stores.sol