diff --git a/src/httprpc.h b/src/httprpc.h
--- a/src/httprpc.h
+++ b/src/httprpc.h
@@ -12,7 +12,6 @@
 #include <string>
 
 class Config;
-class HTTPRequest;
 
 class HTTPRPCRequestProcessor {
 private:
diff --git a/src/miner.h b/src/miner.h
--- a/src/miner.h
+++ b/src/miner.h
@@ -18,9 +18,7 @@
 class CBlockIndex;
 class CChainParams;
 class Config;
-class CReserveKey;
 class CScript;
-class CWallet;
 
 static const bool DEFAULT_PRINTPRIORITY = false;
 
diff --git a/src/qt/addressbookpage.h b/src/qt/addressbookpage.h
--- a/src/qt/addressbookpage.h
+++ b/src/qt/addressbookpage.h
@@ -8,7 +8,6 @@
 #include <QDialog>
 
 class AddressTableModel;
-class OptionsModel;
 class PlatformStyle;
 
 namespace Ui {
@@ -20,7 +19,6 @@
 class QMenu;
 class QModelIndex;
 class QSortFilterProxyModel;
-class QTableView;
 QT_END_NAMESPACE
 
 /** Widget that shows a list of sending or receiving addresses. */
diff --git a/src/qt/bitcoingui.h b/src/qt/bitcoingui.h
--- a/src/qt/bitcoingui.h
+++ b/src/qt/bitcoingui.h
@@ -34,7 +34,6 @@
 class ModalOverlay;
 
 class Config;
-class CWallet;
 
 namespace interfaces {
 class Handler;
diff --git a/src/qt/clientmodel.h b/src/qt/clientmodel.h
--- a/src/qt/clientmodel.h
+++ b/src/qt/clientmodel.h
@@ -11,13 +11,10 @@
 #include <atomic>
 #include <memory>
 
-class AddressTableModel;
 class BanTableModel;
 class OptionsModel;
 class PeerTableModel;
-class TransactionTableModel;
 
-class CWallet;
 class CBlockIndex;
 
 namespace interfaces {
diff --git a/src/qt/coincontroldialog.h b/src/qt/coincontroldialog.h
--- a/src/qt/coincontroldialog.h
+++ b/src/qt/coincontroldialog.h
@@ -20,7 +20,6 @@
 class WalletModel;
 
 class CCoinControl;
-class CTxMemPool;
 
 namespace Ui {
 class CoinControlDialog;
diff --git a/src/qt/receivecoinsdialog.h b/src/qt/receivecoinsdialog.h
--- a/src/qt/receivecoinsdialog.h
+++ b/src/qt/receivecoinsdialog.h
@@ -16,7 +16,6 @@
 #include <QVariant>
 
 class Config;
-class OptionsModel;
 class PlatformStyle;
 class WalletModel;
 
diff --git a/src/qt/sendcoinsdialog.h b/src/qt/sendcoinsdialog.h
--- a/src/qt/sendcoinsdialog.h
+++ b/src/qt/sendcoinsdialog.h
@@ -13,7 +13,6 @@
 #include <QTimer>
 
 class ClientModel;
-class OptionsModel;
 class PlatformStyle;
 class SendCoinsEntry;
 class SendCoinsRecipient;
diff --git a/src/qt/utilitydialog.h b/src/qt/utilitydialog.h
--- a/src/qt/utilitydialog.h
+++ b/src/qt/utilitydialog.h
@@ -9,7 +9,6 @@
 #include <QObject>
 
 class BitcoinGUI;
-class ClientModel;
 
 namespace interfaces {
 class Node;
diff --git a/src/rpc/server.h b/src/rpc/server.h
--- a/src/rpc/server.h
+++ b/src/rpc/server.h
@@ -33,9 +33,7 @@
 void OnStopped(std::function<void()> slot);
 } // namespace RPCServerSignals
 
-class CBlockIndex;
 class Config;
-class CNetAddr;
 
 /**
  * Wrapper for UniValue::VType, which includes typeAny: used to denote don't
diff --git a/src/txmempool.h b/src/txmempool.h
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -27,7 +27,6 @@
 #include <utility>
 #include <vector>
 
-class CAutoFile;
 class CBlockIndex;
 class Config;
 
diff --git a/src/ui_interface.h b/src/ui_interface.h
--- a/src/ui_interface.h
+++ b/src/ui_interface.h
@@ -12,9 +12,7 @@
 #include <boost/signals2/last_value.hpp>
 #include <boost/signals2/signal.hpp>
 
-class CBasicKeyStore;
 class CWallet;
-class uint256;
 class CBlockIndex;
 
 /** General change type (added, updated, removed). */
diff --git a/src/validation.h b/src/validation.h
--- a/src/validation.h
+++ b/src/validation.h
@@ -37,7 +37,6 @@
 
 class CBlockIndex;
 class CBlockTreeDB;
-class CBloomFilter;
 class CChainParams;
 class CChain;
 class CCoinsViewDB;
@@ -47,7 +46,6 @@
 class CScriptCheck;
 class CTxMemPool;
 class CTxUndo;
-class CValidationInterface;
 class CValidationState;
 
 struct CDiskBlockPos;
diff --git a/src/wallet/crypter.h b/src/wallet/crypter.h
--- a/src/wallet/crypter.h
+++ b/src/wallet/crypter.h
@@ -11,8 +11,6 @@
 
 #include <atomic>
 
-class uint256;
-
 const unsigned int WALLET_CRYPTO_KEY_SIZE = 32;
 const unsigned int WALLET_CRYPTO_SALT_SIZE = 8;
 const unsigned int WALLET_CRYPTO_IV_SIZE = 16;