diff --git a/vm.h b/vm.h
index a9897bee3..3a0091a06 100644
--- a/vm.h
+++ b/vm.h
@@ -50,18 +50,18 @@ public:
 class FakeExtVM: public eth::ExtVMFace
 {
 public:
-	FakeExtVM()	{}
+	FakeExtVM() = default;
 	FakeExtVM(eth::BlockInfo const& _previousBlock, eth::BlockInfo const& _currentBlock, unsigned _depth = 0);
 
-	u256 store(u256 _n) override { return std::get<2>(addresses[myAddress])[_n]; }
-	void setStore(u256 _n, u256 _v) override { std::get<2>(addresses[myAddress])[_n] = _v; }
-	u256 balance(Address _a) override { return std::get<0>(addresses[_a]); }
-	void subBalance(u256 _a) override { std::get<0>(addresses[myAddress]) -= _a; }
-	u256 txCount(Address _a) override { return std::get<1>(addresses[_a]); }
-	void suicide(Address _a) override { std::get<0>(addresses[_a]) += std::get<0>(addresses[myAddress]); addresses.erase(myAddress); }
-	bytes const& codeAt(Address _a) override { return std::get<3>(addresses[_a]); }
-	h160 create(u256 _endowment, u256* _gas, bytesConstRef _init, eth::OnOpFunc const&) override;
-	bool call(Address _receiveAddress, u256 _value, bytesConstRef _data, u256* _gas, bytesRef _out, eth::OnOpFunc const&, Address, Address) override;
+	virtual u256 store(u256 _n) override { return std::get<2>(addresses[myAddress])[_n]; }
+	virtual void setStore(u256 _n, u256 _v) override { std::get<2>(addresses[myAddress])[_n] = _v; }
+	virtual u256 balance(Address _a) override { return std::get<0>(addresses[_a]); }
+	virtual void subBalance(u256 _a) override { std::get<0>(addresses[myAddress]) -= _a; }
+	virtual u256 txCount(Address _a) override { return std::get<1>(addresses[_a]); }
+	virtual void suicide(Address _a) override { std::get<0>(addresses[_a]) += std::get<0>(addresses[myAddress]); addresses.erase(myAddress); }
+	virtual bytes const& codeAt(Address _a) override { return std::get<3>(addresses[_a]); }
+	virtual h160 create(u256 _endowment, u256* _gas, bytesConstRef _init, eth::OnOpFunc const&) override;
+	virtual bool call(Address _receiveAddress, u256 _value, bytesConstRef _data, u256* _gas, bytesRef _out, eth::OnOpFunc const&, Address, Address) override;
 	void setTransaction(Address _caller, u256 _value, u256 _gasPrice, bytes const& _data);
 	void setContract(Address _myAddress, u256 _myBalance, u256 _myNonce, std::map<u256, u256> const& _storage, bytes const& _code);
 	void set(Address _a, u256 _myBalance, u256 _myNonce, std::map<u256, u256> const& _storage, bytes const& _code);