diff --git a/src/dsnotificationinterface.h b/src/dsnotificationinterface.h
index 9e96c9afe..8e7df34a3 100644
--- a/src/dsnotificationinterface.h
+++ b/src/dsnotificationinterface.h
@@ -21,7 +21,7 @@ protected:
     void AcceptedBlockHeader(const CBlockIndex *pindexNew) override;
     void NotifyHeaderTip(const CBlockIndex *pindexNew, bool fInitialDownload) override;
     void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) override;
-    void SyncTransaction(const CTransaction &tx, const CBlockIndex *pindex, int posInBlock);
+    void SyncTransaction(const CTransaction &tx, const CBlockIndex *pindex, int posInBlock) override;
 
 private:
     CConnman& connman;
diff --git a/src/governance-exceptions.h b/src/governance-exceptions.h
index a125e970c..6df354f71 100644
--- a/src/governance-exceptions.h
+++ b/src/governance-exceptions.h
@@ -76,7 +76,7 @@ public:
 
     virtual ~CGovernanceException() throw() {}
 
-    virtual const char* what() const throw()
+    virtual const char* what() const throw() override 
     {
         return strMessage.c_str();
     }
diff --git a/src/httprpc.cpp b/src/httprpc.cpp
index fe6dfd6af..bd59cc1a6 100644
--- a/src/httprpc.cpp
+++ b/src/httprpc.cpp
@@ -48,11 +48,11 @@ public:
     HTTPRPCTimerInterface(struct event_base* _base) : base(_base)
     {
     }
-    const char* Name()
+    const char* Name() override
     {
         return "HTTP";
     }
-    RPCTimerBase* NewTimer(boost::function<void(void)>& func, int64_t millis)
+    RPCTimerBase* NewTimer(boost::function<void(void)>& func, int64_t millis) override
     {
         return new HTTPRPCTimer(base, func, millis);
     }
diff --git a/src/httpserver.cpp b/src/httpserver.cpp
index 79e9f1ecb..1546211d5 100644
--- a/src/httpserver.cpp
+++ b/src/httpserver.cpp
@@ -46,7 +46,7 @@ public:
         req(std::move(_req)), path(_path), func(_func)
     {
     }
-    void operator()()
+    void operator()() override
     {
         func(req.get(), path);
     }
diff --git a/src/keystore.h b/src/keystore.h
index ed103659e..e81e376cf 100644
--- a/src/keystore.h
+++ b/src/keystore.h
@@ -64,9 +64,9 @@ protected:
     CHDChain hdChain;
 
 public:
-    bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey);
-    bool GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const;
-    bool HaveKey(const CKeyID &address) const
+    bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey) override;
+    bool GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const override;
+    bool HaveKey(const CKeyID &address) const override
     {
         bool result;
         {
@@ -75,7 +75,7 @@ public:
         }
         return result;
     }
-    void GetKeys(std::set<CKeyID> &setAddress) const
+    void GetKeys(std::set<CKeyID> &setAddress) const override
     {
         setAddress.clear();
         {
@@ -88,7 +88,7 @@ public:
             }
         }
     }
-    bool GetKey(const CKeyID &address, CKey &keyOut) const
+    bool GetKey(const CKeyID &address, CKey &keyOut) const override
     {
         {
             LOCK(cs_KeyStore);
@@ -101,16 +101,16 @@ public:
         }
         return false;
     }
-    virtual bool AddCScript(const CScript& redeemScript);
-    virtual bool HaveCScript(const CScriptID &hash) const;
-    virtual bool GetCScript(const CScriptID &hash, CScript& redeemScriptOut) const;
+    virtual bool AddCScript(const CScript& redeemScript) override;
+    virtual bool HaveCScript(const CScriptID &hash) const override;
+    virtual bool GetCScript(const CScriptID &hash, CScript& redeemScriptOut) const override;
 
-    virtual bool AddWatchOnly(const CScript &dest);
-    virtual bool RemoveWatchOnly(const CScript &dest);
-    virtual bool HaveWatchOnly(const CScript &dest) const;
-    virtual bool HaveWatchOnly() const;
+    virtual bool AddWatchOnly(const CScript &dest) override;
+    virtual bool RemoveWatchOnly(const CScript &dest) override;
+    virtual bool HaveWatchOnly(const CScript &dest) const override;
+    virtual bool HaveWatchOnly() const override;
 
-    bool GetHDChain(CHDChain& hdChainRet) const;
+    virtual bool GetHDChain(CHDChain& hdChainRet) const;
 };
 
 typedef std::vector<unsigned char, secure_allocator<unsigned char> > CKeyingMaterial;
diff --git a/src/net_processing.h b/src/net_processing.h
index 8d4408f46..317f8eafa 100644
--- a/src/net_processing.h
+++ b/src/net_processing.h
@@ -33,9 +33,9 @@ private:
 public:
     PeerLogicValidation(CConnman* connmanIn);
 
-    virtual void SyncTransaction(const CTransaction& tx, const CBlockIndex* pindex, int nPosInBlock);
-    virtual void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload);
-    virtual void BlockChecked(const CBlock& block, const CValidationState& state);
+    virtual void SyncTransaction(const CTransaction& tx, const CBlockIndex* pindex, int nPosInBlock) override;
+    virtual void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) override;
+    virtual void BlockChecked(const CBlock& block, const CValidationState& state) override;
 };
 
 struct CNodeStateStats {
diff --git a/src/qt/coincontroltreewidget.h b/src/qt/coincontroltreewidget.h
index 62645fcdb..09059f993 100644
--- a/src/qt/coincontroltreewidget.h
+++ b/src/qt/coincontroltreewidget.h
@@ -16,7 +16,7 @@ public:
     explicit CoinControlTreeWidget(QWidget *parent = 0);
 
 protected:
-    virtual void keyPressEvent(QKeyEvent *event);
+    virtual void keyPressEvent(QKeyEvent *event) override;
 };
 
 #endif // BITCOIN_QT_COINCONTROLTREEWIDGET_H
diff --git a/src/qt/receivecoinsdialog.h b/src/qt/receivecoinsdialog.h
index d137f1616..0520eb4b3 100644
--- a/src/qt/receivecoinsdialog.h
+++ b/src/qt/receivecoinsdialog.h
@@ -51,7 +51,7 @@ public Q_SLOTS:
     void accept();
 
 protected:
-    virtual void keyPressEvent(QKeyEvent *event);
+    virtual void keyPressEvent(QKeyEvent *event) override;
 
 private:
     Ui::ReceiveCoinsDialog *ui;
@@ -62,7 +62,7 @@ private:
 
     QModelIndex selectedRow();
     void copyColumnToClipboard(int column);
-    virtual void resizeEvent(QResizeEvent *event);
+    virtual void resizeEvent(QResizeEvent *event) override;
 
 private Q_SLOTS:
     void on_receiveButton_clicked();
diff --git a/src/qt/receiverequestdialog.h b/src/qt/receiverequestdialog.h
index 676745a85..aef30732c 100644
--- a/src/qt/receiverequestdialog.h
+++ b/src/qt/receiverequestdialog.h
@@ -38,8 +38,8 @@ public Q_SLOTS:
     void copyImage();
 
 protected:
-    virtual void mousePressEvent(QMouseEvent *event);
-    virtual void contextMenuEvent(QContextMenuEvent *event);
+    virtual void mousePressEvent(QMouseEvent *event) override;
+    virtual void contextMenuEvent(QContextMenuEvent *event) override;
 
 private:
     QMenu *contextMenu;
diff --git a/src/qt/rpcconsole.cpp b/src/qt/rpcconsole.cpp
index 223d0389e..b8d9ecc87 100644
--- a/src/qt/rpcconsole.cpp
+++ b/src/qt/rpcconsole.cpp
@@ -127,8 +127,8 @@ class QtRPCTimerInterface: public RPCTimerInterface
 {
 public:
     ~QtRPCTimerInterface() {}
-    const char *Name() { return "Qt"; }
-    RPCTimerBase* NewTimer(boost::function<void(void)>& func, int64_t millis)
+    const char *Name() override { return "Qt"; }
+    RPCTimerBase* NewTimer(boost::function<void(void)>& func, int64_t millis) override
     {
         return new QtRPCTimerBase(func, millis);
     }
diff --git a/src/qt/transactionview.h b/src/qt/transactionview.h
index 2a2ad4912..340f2e191 100644
--- a/src/qt/transactionview.h
+++ b/src/qt/transactionview.h
@@ -81,7 +81,7 @@ private:
 
     GUIUtil::TableViewLastColumnResizingFixer *columnResizingFixer;
 
-    virtual void resizeEvent(QResizeEvent* event);
+    virtual void resizeEvent(QResizeEvent* event) override;
 
     bool eventFilter(QObject *obj, QEvent *event);
 
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index a463283cb..87e084fd1 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -743,7 +743,7 @@ public:
     submitblock_StateCatcher(const uint256 &hashIn) : hash(hashIn), found(false), state() {}
 
 protected:
-    virtual void BlockChecked(const CBlock& block, const CValidationState& stateIn) {
+    virtual void BlockChecked(const CBlock& block, const CValidationState& stateIn) override {
         if (block.GetHash() != hash)
             return;
         found = true;
diff --git a/src/script/interpreter.h b/src/script/interpreter.h
index 6de904878..801e23b36 100644
--- a/src/script/interpreter.h
+++ b/src/script/interpreter.h
@@ -128,9 +128,9 @@ protected:
 
 public:
     TransactionSignatureChecker(const CTransaction* txToIn, unsigned int nInIn) : txTo(txToIn), nIn(nInIn) {}
-    bool CheckSig(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode) const;
-    bool CheckLockTime(const CScriptNum& nLockTime) const;
-    bool CheckSequence(const CScriptNum& nSequence) const;
+    bool CheckSig(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode) const override;
+    bool CheckLockTime(const CScriptNum& nLockTime) const override;
+    bool CheckSequence(const CScriptNum& nSequence) const override;
 };
 
 class MutableTransactionSignatureChecker : public TransactionSignatureChecker
diff --git a/src/script/sigcache.h b/src/script/sigcache.h
index 9cd3ea394..15ee161de 100644
--- a/src/script/sigcache.h
+++ b/src/script/sigcache.h
@@ -27,7 +27,7 @@ private:
 public:
     CachingTransactionSignatureChecker(const CTransaction* txToIn, unsigned int nInIn, bool storeIn=true) : TransactionSignatureChecker(txToIn, nInIn), store(storeIn) {}
 
-    bool VerifySignature(const std::vector<unsigned char>& vchSig, const CPubKey& vchPubKey, const uint256& sighash) const;
+    bool VerifySignature(const std::vector<unsigned char>& vchSig, const CPubKey& vchPubKey, const uint256& sighash) const override;
 };
 
 void InitSignatureCache();
diff --git a/src/script/sign.cpp b/src/script/sign.cpp
index 2f4111f78..951c1bc1e 100644
--- a/src/script/sign.cpp
+++ b/src/script/sign.cpp
@@ -284,7 +284,7 @@ class DummySignatureChecker : public BaseSignatureChecker
 public:
     DummySignatureChecker() {}
 
-    bool CheckSig(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode) const
+    bool CheckSig(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode) const override
     {
         return true;
     }
diff --git a/src/script/sign.h b/src/script/sign.h
index b86423d52..ee8f55180 100644
--- a/src/script/sign.h
+++ b/src/script/sign.h
@@ -39,16 +39,16 @@ class TransactionSignatureCreator : public BaseSignatureCreator {
 
 public:
     TransactionSignatureCreator(const CKeyStore* keystoreIn, const CTransaction* txToIn, unsigned int nInIn, int nHashTypeIn=SIGHASH_ALL);
-    const BaseSignatureChecker& Checker() const { return checker; }
-    bool CreateSig(std::vector<unsigned char>& vchSig, const CKeyID& keyid, const CScript& scriptCode) const;
+    const BaseSignatureChecker& Checker() const  override{ return checker; }
+    bool CreateSig(std::vector<unsigned char>& vchSig, const CKeyID& keyid, const CScript& scriptCode) const override;
 };
 
 /** A signature creator that just produces 72-byte empty signatures. */
 class DummySignatureCreator : public BaseSignatureCreator {
 public:
     DummySignatureCreator(const CKeyStore* keystoreIn) : BaseSignatureCreator(keystoreIn) {}
-    const BaseSignatureChecker& Checker() const;
-    bool CreateSig(std::vector<unsigned char>& vchSig, const CKeyID& keyid, const CScript& scriptCode) const;
+    const BaseSignatureChecker& Checker() const override;
+    bool CreateSig(std::vector<unsigned char>& vchSig, const CKeyID& keyid, const CScript& scriptCode) const override;
 };
 
 /** Produce a script signature using a generic signature creator. */
diff --git a/src/test/addrman_tests.cpp b/src/test/addrman_tests.cpp
index c80a46c98..535faa2b1 100644
--- a/src/test/addrman_tests.cpp
+++ b/src/test/addrman_tests.cpp
@@ -27,7 +27,7 @@ public:
         insecure_rand = FastRandomContext(true);
     }
 
-    int RandomInt(int nMax)
+    int RandomInt(int nMax) override
     {
         state = (CHashWriter(SER_GETHASH, 0) << state).GetHash().GetCheapHash();
         return (unsigned int)(state % nMax);
diff --git a/src/test/net_tests.cpp b/src/test/net_tests.cpp
index 33f2102c6..7a3195704 100644
--- a/src/test/net_tests.cpp
+++ b/src/test/net_tests.cpp
@@ -28,7 +28,7 @@ public:
 class CAddrManUncorrupted : public CAddrManSerializationMock
 {
 public:
-    void Serialize(CDataStream& s) const
+    void Serialize(CDataStream& s) const override
     {
         CAddrMan::Serialize(s);
     }
@@ -37,7 +37,7 @@ public:
 class CAddrManCorrupted : public CAddrManSerializationMock
 {
 public:
-    void Serialize(CDataStream& s) const
+    void Serialize(CDataStream& s) const override
     {
         // Produces corrupt output that claims addrman has 20 addrs when it only has one addr.
         unsigned char nVersion = 1;
diff --git a/src/test/versionbits_tests.cpp b/src/test/versionbits_tests.cpp
index 2b4f54b18..0e38f627f 100644
--- a/src/test/versionbits_tests.cpp
+++ b/src/test/versionbits_tests.cpp
@@ -23,11 +23,11 @@ private:
     mutable ThresholdConditionCache cache;
 
 public:
-    int64_t BeginTime(const Consensus::Params& params) const { return TestTime(10000); }
-    int64_t EndTime(const Consensus::Params& params) const { return TestTime(20000); }
-    int Period(const Consensus::Params& params) const { return 1000; }
-    int Threshold(const Consensus::Params& params) const { return 900; }
-    bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const { return (pindex->nVersion & 0x100); }
+    int64_t BeginTime(const Consensus::Params& params) const override { return TestTime(10000); }
+    int64_t EndTime(const Consensus::Params& params) const override { return TestTime(20000); }
+    int Period(const Consensus::Params& params) const override { return 1000; }
+    int Threshold(const Consensus::Params& params) const override { return 900; }
+    bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const override { return (pindex->nVersion & 0x100); }
 
     ThresholdState GetStateFor(const CBlockIndex* pindexPrev) const { return AbstractThresholdConditionChecker::GetStateFor(pindexPrev, paramsDummy, cache); }
     int GetStateSinceHeightFor(const CBlockIndex* pindexPrev) const { return AbstractThresholdConditionChecker::GetStateSinceHeightFor(pindexPrev, paramsDummy, cache); }
diff --git a/src/txdb.h b/src/txdb.h
index c709fd0ca..9e7c5b699 100644
--- a/src/txdb.h
+++ b/src/txdb.h
@@ -74,6 +74,7 @@ protected:
 public:
     CCoinsViewDB(size_t nCacheSize, bool fMemory = false, bool fWipe = false);
 
+
     bool GetCoin(const COutPoint &outpoint, Coin &coin) const override;
     bool HaveCoin(const COutPoint &outpoint) const override;
     uint256 GetBestBlock() const override;
@@ -91,12 +92,12 @@ class CCoinsViewDBCursor: public CCoinsViewCursor
 public:
     ~CCoinsViewDBCursor() {}
 
-    bool GetKey(COutPoint &key) const;
-    bool GetValue(Coin &coin) const;
-    unsigned int GetValueSize() const;
+    bool GetKey(COutPoint &key) const override;
+    bool GetValue(Coin &coin) const override;
+    unsigned int GetValueSize() const override;
 
-    bool Valid() const;
-    void Next();
+    bool Valid() const override;
+    void Next() override;
 
 private:
     CCoinsViewDBCursor(CDBIterator* pcursorIn, const uint256 &hashBlockIn):
diff --git a/src/validation.cpp b/src/validation.cpp
index 7b52eb9e6..49baefa79 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1988,12 +1988,12 @@ private:
 public:
     WarningBitsConditionChecker(int bitIn) : bit(bitIn) {}
 
-    int64_t BeginTime(const Consensus::Params& params) const { return 0; }
-    int64_t EndTime(const Consensus::Params& params) const { return std::numeric_limits<int64_t>::max(); }
-    int Period(const Consensus::Params& params) const { return params.nMinerConfirmationWindow; }
-    int Threshold(const Consensus::Params& params) const { return params.nRuleChangeActivationThreshold; }
+    int64_t BeginTime(const Consensus::Params& params) const override { return 0; }
+    int64_t EndTime(const Consensus::Params& params) const override { return std::numeric_limits<int64_t>::max(); }
+    int Period(const Consensus::Params& params) const override { return params.nMinerConfirmationWindow; }
+    int Threshold(const Consensus::Params& params) const override { return params.nRuleChangeActivationThreshold; }
 
-    bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const
+    bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const override
     {
         return ((pindex->nVersion & VERSIONBITS_TOP_MASK) == VERSIONBITS_TOP_BITS) &&
                ((pindex->nVersion >> bit) & 1) != 0 &&
diff --git a/src/validationinterface.h b/src/validationinterface.h
index 360e4005c..46820cd32 100644
--- a/src/validationinterface.h
+++ b/src/validationinterface.h
@@ -42,9 +42,9 @@ protected:
     virtual void Inventory(const uint256 &hash) {}
     virtual void ResendWalletTransactions(int64_t nBestBlockTime, CConnman* connman) {}
     virtual void BlockChecked(const CBlock&, const CValidationState&) {}
-    virtual void GetScriptForMining(boost::shared_ptr<CReserveScript>&) {};
-    virtual void ResetRequestCount(const uint256 &hash) {};
-    virtual void NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& block) {};
+    virtual void GetScriptForMining(boost::shared_ptr<CReserveScript>&) {}
+    virtual void ResetRequestCount(const uint256 &hash) {}
+    virtual void NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& block) {}
     friend void ::RegisterValidationInterface(CValidationInterface*);
     friend void ::UnregisterValidationInterface(CValidationInterface*);
     friend void ::UnregisterAllValidationInterfaces();
diff --git a/src/versionbits.cpp b/src/versionbits.cpp
index fbbcdb427..af37b6350 100644
--- a/src/versionbits.cpp
+++ b/src/versionbits.cpp
@@ -153,12 +153,12 @@ private:
     const Consensus::DeploymentPos id;
 
 protected:
-    int64_t BeginTime(const Consensus::Params& params) const { return params.vDeployments[id].nStartTime; }
-    int64_t EndTime(const Consensus::Params& params) const { return params.vDeployments[id].nTimeout; }
-    int Period(const Consensus::Params& params) const { return params.vDeployments[id].nWindowSize ? params.vDeployments[id].nWindowSize : params.nMinerConfirmationWindow; }
-    int Threshold(const Consensus::Params& params) const { return params.vDeployments[id].nThreshold ? params.vDeployments[id].nThreshold : params.nRuleChangeActivationThreshold; }
+    int64_t BeginTime(const Consensus::Params& params) const override { return params.vDeployments[id].nStartTime; }
+    int64_t EndTime(const Consensus::Params& params) const override { return params.vDeployments[id].nTimeout; }
+    int Period(const Consensus::Params& params) const override { return params.vDeployments[id].nWindowSize ? params.vDeployments[id].nWindowSize : params.nMinerConfirmationWindow; }
+    int Threshold(const Consensus::Params& params) const override { return params.vDeployments[id].nThreshold ? params.vDeployments[id].nThreshold : params.nRuleChangeActivationThreshold; }
 
-    bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const
+    bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const override
     {
         return (((pindex->nVersion & VERSIONBITS_TOP_MASK) == VERSIONBITS_TOP_BITS) && (pindex->nVersion & Mask(params)) != 0);
     }
diff --git a/src/wallet/crypter.h b/src/wallet/crypter.h
index 3e12e4b3f..1b5cdbcff 100644
--- a/src/wallet/crypter.h
+++ b/src/wallet/crypter.h
@@ -189,8 +189,8 @@ public:
     bool Lock(bool fAllowMixing = false);
 
     virtual bool AddCryptedKey(const CPubKey &vchPubKey, const std::vector<unsigned char> &vchCryptedSecret);
-    bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey);
-    bool HaveKey(const CKeyID &address) const
+    bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey) override;
+    bool HaveKey(const CKeyID &address) const override
     {
         {
             LOCK(cs_KeyStore);
@@ -200,9 +200,9 @@ public:
         }
         return false;
     }
-    bool GetKey(const CKeyID &address, CKey& keyOut) const;
-    bool GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const;
-    void GetKeys(std::set<CKeyID> &setAddress) const
+    bool GetKey(const CKeyID &address, CKey& keyOut) const override;
+    bool GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const override;
+    void GetKeys(std::set<CKeyID> &setAddress) const override
     {
         if (!IsCrypted())
         {
@@ -218,7 +218,7 @@ public:
         }
     }
 
-    bool GetHDChain(CHDChain& hdChainRet) const;
+    virtual bool GetHDChain(CHDChain& hdChainRet) const override;
 
     /**
      * Wallet status (encrypted, locked) changed.
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index f7851e033..c45377f20 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -877,6 +877,7 @@ public:
 
     //! Adds a watch-only address to the store, and saves it to disk.
     bool AddWatchOnly(const CScript& dest, int64_t nCreateTime);
+
     bool RemoveWatchOnly(const CScript &dest) override;
     //! Adds a watch-only address to the store, without saving it to disk (used by LoadWallet)
     bool LoadWatchOnly(const CScript &dest);
@@ -1142,7 +1143,7 @@ public:
     void ReturnKey();
     bool GetReservedKey(CPubKey &pubkey, bool fInternalIn /*= false*/);
     void KeepKey();
-    void KeepScript() { KeepKey(); }
+    void KeepScript() override { KeepKey(); }
 };
 
 
diff --git a/src/zmq/zmqnotificationinterface.h b/src/zmq/zmqnotificationinterface.h
index 44bd8b1c8..13b5c8bf9 100644
--- a/src/zmq/zmqnotificationinterface.h
+++ b/src/zmq/zmqnotificationinterface.h
@@ -24,9 +24,9 @@ protected:
     void Shutdown();
 
     // CValidationInterface
-    void SyncTransaction(const CTransaction& tx, const CBlockIndex *pindex, int posInBlock);
-    void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload);
-    void NotifyTransactionLock(const CTransaction &tx);
+    void SyncTransaction(const CTransaction& tx, const CBlockIndex *pindex, int posInBlock) override;
+    void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) override;
+    void NotifyTransactionLock(const CTransaction &tx) override;
 
 private:
     CZMQNotificationInterface();
diff --git a/src/zmq/zmqpublishnotifier.h b/src/zmq/zmqpublishnotifier.h
index 09a7793bc..4ade12cdc 100644
--- a/src/zmq/zmqpublishnotifier.h
+++ b/src/zmq/zmqpublishnotifier.h
@@ -24,44 +24,44 @@ public:
     */
     bool SendMessage(const char *command, const void* data, size_t size);
 
-    bool Initialize(void *pcontext);
-    void Shutdown();
+    bool Initialize(void *pcontext) override;
+    void Shutdown() override;
 };
 
 class CZMQPublishHashBlockNotifier : public CZMQAbstractPublishNotifier
 {
 public:
-    bool NotifyBlock(const CBlockIndex *pindex);
+    bool NotifyBlock(const CBlockIndex *pindex) override;
 };
 
 class CZMQPublishHashTransactionNotifier : public CZMQAbstractPublishNotifier
 {
 public:
-    bool NotifyTransaction(const CTransaction &transaction);
+    bool NotifyTransaction(const CTransaction &transaction) override;
 };
 
 class CZMQPublishHashTransactionLockNotifier : public CZMQAbstractPublishNotifier
 {
 public:
-    bool NotifyTransactionLock(const CTransaction &transaction);
+    bool NotifyTransactionLock(const CTransaction &transaction) override;
 };
 
 class CZMQPublishRawBlockNotifier : public CZMQAbstractPublishNotifier
 {
 public:
-    bool NotifyBlock(const CBlockIndex *pindex);
+    bool NotifyBlock(const CBlockIndex *pindex) override;
 };
 
 class CZMQPublishRawTransactionNotifier : public CZMQAbstractPublishNotifier
 {
 public:
-    bool NotifyTransaction(const CTransaction &transaction);
+    bool NotifyTransaction(const CTransaction &transaction) override;
 };
 
 class CZMQPublishRawTransactionLockNotifier : public CZMQAbstractPublishNotifier
 {
 public:
-    bool NotifyTransactionLock(const CTransaction &transaction);
+    bool NotifyTransactionLock(const CTransaction &transaction) override;
 };
 
 #endif // BITCOIN_ZMQ_ZMQPUBLISHNOTIFIER_H