diff --git a/src/fs.cpp b/src/fs.cpp
--- a/src/fs.cpp
+++ b/src/fs.cpp
@@ -6,9 +6,11 @@
 #include <fs.h>
 
 #ifndef WIN32
+#include <cstring>
 #include <fcntl.h>
 #include <sys/file.h>
 #include <sys/utsname.h>
+#include <unistd.h>
 #else
 #ifndef NOMINMAX
 #define NOMINMAX
diff --git a/src/qt/coincontroldialog.cpp b/src/qt/coincontroldialog.cpp
--- a/src/qt/coincontroldialog.cpp
+++ b/src/qt/coincontroldialog.cpp
@@ -448,14 +448,12 @@
     // nPayAmount
     Amount nPayAmount = Amount::zero();
     bool fDust = false;
-    CMutableTransaction txDummy;
     for (const Amount &amount : CoinControlDialog::payAmounts) {
         nPayAmount += amount;
 
         if (amount > Amount::zero()) {
             // Assumes a p2pkh script size
             CTxOut txout(amount, CScript() << std::vector<uint8_t>(24, 0));
-            txDummy.vout.push_back(txout);
             fDust |= IsDust(txout, model->node().getDustRelayFee());
         }
     }
diff --git a/src/qt/transactionrecord.cpp b/src/qt/transactionrecord.cpp
--- a/src/qt/transactionrecord.cpp
+++ b/src/qt/transactionrecord.cpp
@@ -46,7 +46,6 @@
             isminetype mine = wtx.txout_is_mine[i];
             if (mine) {
                 TransactionRecord sub(txid, nTime);
-                CTxDestination address;
                 sub.idx = i; // vout index
                 sub.credit = txout.nValue;
                 sub.involvesWatchAddress = mine & ISMINE_WATCH_ONLY;
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -828,7 +828,6 @@
 
 bool CWallet::IsSpentKey(const TxId &txid, unsigned int n) const {
     AssertLockHeld(cs_wallet);
-    CTxDestination dst;
     const CWalletTx *srctx = GetWalletTx(txid);
     if (srctx) {
         assert(srctx->tx->vout.size() > n);