diff --git a/configure.ac b/configure.ac
index ca19fa8b6f303..61a67d82d6718 100644
--- a/configure.ac
+++ b/configure.ac
@@ -322,7 +322,7 @@ AC_ARG_ENABLE([gprof],
 dnl Turn warnings into errors
 AC_ARG_ENABLE([werror],
     [AS_HELP_STRING([--enable-werror],
-                    [Treat certain compiler warnings as errors (default is no)])],
+                    [Treat compiler warnings as errors (default is no)])],
     [enable_werror=$enableval],
     [enable_werror=no])
 
@@ -450,32 +450,22 @@ if test "x$enable_werror" = "xyes"; then
   if test "x$CXXFLAG_WERROR" = "x"; then
     AC_MSG_ERROR("enable-werror set but -Werror is not usable")
   fi
-  AX_CHECK_COMPILE_FLAG([-Werror=reorder],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=reorder"],,[[$CXXFLAG_WERROR]])
-  AX_CHECK_COMPILE_FLAG([-Werror=gnu],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=gnu"],,[[$CXXFLAG_WERROR]])
-  AX_CHECK_COMPILE_FLAG([-Werror=vla],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=vla"],,[[$CXXFLAG_WERROR]])
-  AX_CHECK_COMPILE_FLAG([-Werror=shadow-field],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=shadow-field"],,[[$CXXFLAG_WERROR]])
-  AX_CHECK_COMPILE_FLAG([-Werror=switch],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=switch"],,[[$CXXFLAG_WERROR]])
-  AX_CHECK_COMPILE_FLAG([-Werror=thread-safety],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=thread-safety"],,[[$CXXFLAG_WERROR]])
-  AX_CHECK_COMPILE_FLAG([-Werror=range-loop-analysis],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=range-loop-analysis"],,[[$CXXFLAG_WERROR]])
-  AX_CHECK_COMPILE_FLAG([-Werror=unused-variable],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=unused-variable"],,[[$CXXFLAG_WERROR]])
-  AX_CHECK_COMPILE_FLAG([-Werror=date-time],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=date-time"],,[[$CXXFLAG_WERROR]])
+  ERROR_CXXFLAGS=$CXXFLAG_WERROR
 
   dnl -Wreturn-type is broken in GCC for MinGW-w64.
   dnl https://sourceforge.net/p/mingw-w64/bugs/306/
-  AX_CHECK_COMPILE_FLAG([-Werror=return-type], [ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=return-type"], [], [$CXXFLAG_WERROR],
+  AX_CHECK_COMPILE_FLAG([-Werror=return-type], [], [ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Wno-error=return-type"], [$CXXFLAG_WERROR],
                         [AC_LANG_SOURCE([[#include <cassert>
                                           int f(){ assert(false); }]])])
-
-  AX_CHECK_COMPILE_FLAG([-Werror=conditional-uninitialized],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=conditional-uninitialized"],,[[$CXXFLAG_WERROR]])
-  AX_CHECK_COMPILE_FLAG([-Werror=sign-compare],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=sign-compare"],,[[$CXXFLAG_WERROR]])
-  AX_CHECK_COMPILE_FLAG([-Wsuggest-override], [WARN_CXXFLAGS="$WARN_CXXFLAGS -Wsuggest-override"], [], [$CXXFLAG_WERROR])
-  AX_CHECK_COMPILE_FLAG([-Werror=unreachable-code-loop-increment],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=unreachable-code-loop-increment"],,[[$CXXFLAG_WERROR]])
-  AX_CHECK_COMPILE_FLAG([-Werror=mismatched-tags], [ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=mismatched-tags"], [], [$CXXFLAG_WERROR])
-  AX_CHECK_COMPILE_FLAG([-Werror=implicit-fallthrough], [ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=implicit-fallthrough"], [], [$CXXFLAG_WERROR])
-
-  if test x$suppress_external_warnings != xno ; then
-    AX_CHECK_COMPILE_FLAG([-Werror=documentation],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=documentation"],,[[$CXXFLAG_WERROR]])
-  fi
+  dnl -Wstringop-overread is broken in GCC 11.
+  AC_COMPILE_IFELSE(
+    [AC_LANG_PROGRAM([[]],
+         [[#if __GNUC__ == 11
+           #error -Wstringop-overread is broken in GCC 11
+           #endif
+          ]])],
+    [],
+    [ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Wno-stringop-overread"])
 fi
 
 if test "x$CXXFLAGS_overridden" = "xno"; then
@@ -484,6 +474,7 @@ if test "x$CXXFLAGS_overridden" = "xno"; then
   AX_CHECK_COMPILE_FLAG([-Wgnu],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wgnu"],,[[$CXXFLAG_WERROR]])
   dnl some compilers will ignore -Wformat-security without -Wformat, so just combine the two here.
   AX_CHECK_COMPILE_FLAG([-Wformat -Wformat-security],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wformat -Wformat-security"],,[[$CXXFLAG_WERROR]])
+  AX_CHECK_COMPILE_FLAG([-Wreorder],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wreorder"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Wvla],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wvla"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Wshadow-field],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wshadow-field"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Wthread-safety],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wthread-safety"],,[[$CXXFLAG_WERROR]])
@@ -496,6 +487,8 @@ if test "x$CXXFLAGS_overridden" = "xno"; then
   AX_CHECK_COMPILE_FLAG([-Wduplicated-cond],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wduplicated-cond"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Wlogical-op],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wlogical-op"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Woverloaded-virtual],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Woverloaded-virtual"],,[[$CXXFLAG_WERROR]])
+  dnl -Wsuggest-override is broken with GCC before 9.2
+  dnl https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78010
   AX_CHECK_COMPILE_FLAG([-Wsuggest-override],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wsuggest-override"],,[[$CXXFLAG_WERROR]],
                         [AC_LANG_SOURCE([[struct A { virtual void f(); }; struct B : A { void f() final; };]])])
   AX_CHECK_COMPILE_FLAG([-Wunreachable-code-loop-increment],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wunreachable-code-loop-increment"],,[[$CXXFLAG_WERROR]])
diff --git a/src/qt/appearancewidget.cpp b/src/qt/appearancewidget.cpp
index d52c03971a9b0..2a26902d017aa 100644
--- a/src/qt/appearancewidget.cpp
+++ b/src/qt/appearancewidget.cpp
@@ -46,11 +46,11 @@ AppearanceWidget::AppearanceWidget(QWidget* parent) :
     connect(ui->fontWeightNormalSlider, &QSlider::valueChanged, [this](auto nValue) { updateFontWeightNormal(nValue); });
     connect(ui->fontWeightBoldSlider, &QSlider::valueChanged, [this](auto nValue) { updateFontWeightBold(nValue); });
 
-    connect(ui->theme, &QComboBox::currentTextChanged, [=]() { Q_EMIT appearanceChanged(); });
-    connect(ui->fontFamily, &QComboBox::currentTextChanged, [=]() { Q_EMIT appearanceChanged(); });
-    connect(ui->fontScaleSlider, &QSlider::sliderReleased, [=]() { Q_EMIT appearanceChanged(); });
-    connect(ui->fontWeightNormalSlider, &QSlider::sliderReleased, [=]() { Q_EMIT appearanceChanged(); });
-    connect(ui->fontWeightBoldSlider, &QSlider::sliderReleased, [=]() { Q_EMIT appearanceChanged(); });
+    connect(ui->theme, &QComboBox::currentTextChanged, [this]() { Q_EMIT appearanceChanged(); });
+    connect(ui->fontFamily, &QComboBox::currentTextChanged, [this]() { Q_EMIT appearanceChanged(); });
+    connect(ui->fontScaleSlider, &QSlider::sliderReleased, [this]() { Q_EMIT appearanceChanged(); });
+    connect(ui->fontWeightNormalSlider, &QSlider::sliderReleased, [this]() { Q_EMIT appearanceChanged(); });
+    connect(ui->fontWeightBoldSlider, &QSlider::sliderReleased, [this]() { Q_EMIT appearanceChanged(); });
 }
 
 AppearanceWidget::~AppearanceWidget()
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index 2628bdf3afad8..36609e80684bd 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -240,7 +240,7 @@ BitcoinGUI::BitcoinGUI(interfaces::Node& node, const NetworkStyle* networkStyle,
     bool fDebugCustomStyleSheets = gArgs.GetBoolArg("-debug-ui", false) && GUIUtil::isStyleSheetDirectoryCustom();
     if (fDebugCustomStyleSheets) {
         timerCustomCss = new QTimer(this);
-        QObject::connect(timerCustomCss, &QTimer::timeout, [=]() {
+        QObject::connect(timerCustomCss, &QTimer::timeout, [this]() {
             if (!m_node.shutdownRequested()) {
                 GUIUtil::loadStyleSheet();
             }
@@ -291,7 +291,7 @@ void BitcoinGUI::startSpinner()
     };
 
     timerSpinner = new QTimer(this);
-    QObject::connect(timerSpinner, &QTimer::timeout, [=]() {
+    QObject::connect(timerSpinner, &QTimer::timeout, [this, getNextFrame]() {
         if (timerSpinner == nullptr) {
             return;
         }
@@ -319,7 +319,7 @@ void BitcoinGUI::startConnectingAnimation()
     }
 
     timerConnecting = new QTimer(this);
-    QObject::connect(timerConnecting, &QTimer::timeout, [=]() {
+    QObject::connect(timerConnecting, &QTimer::timeout, [this]() {
 
         if (timerConnecting == nullptr) {
             return;
@@ -1353,7 +1353,7 @@ void BitcoinGUI::openOptionsDialogWithTab(OptionsDialog::Tab tab)
     connect(dlg, &OptionsDialog::quitOnReset, this, &BitcoinGUI::quitRequested);
     dlg->setCurrentTab(tab);
     dlg->setModel(clientModel->getOptionsModel());
-    connect(dlg, &OptionsDialog::appearanceChanged, [=]() {
+    connect(dlg, &OptionsDialog::appearanceChanged, [this]() {
         updateWidth();
     });
     GUIUtil::ShowModalDialogAndDeleteOnClose(dlg);
diff --git a/src/qt/optionsdialog.cpp b/src/qt/optionsdialog.cpp
index 903daba278af4..28fd6de091de9 100644
--- a/src/qt/optionsdialog.cpp
+++ b/src/qt/optionsdialog.cpp
@@ -194,7 +194,7 @@ OptionsDialog::OptionsDialog(QWidget *parent, bool enableWallet) :
     appearanceLayout->addWidget(appearance);
     ui->widgetAppearance->setLayout(appearanceLayout);
 
-    connect(appearance, &AppearanceWidget::appearanceChanged, [=](){
+    connect(appearance, &AppearanceWidget::appearanceChanged, [this](){
         updateWidth();
         Q_EMIT appearanceChanged();
     });
@@ -277,13 +277,13 @@ void OptionsDialog::setModel(OptionsModel *_model)
     connect(ui->lang, qOverload<>(&QValueComboBox::valueChanged), [this]{ showRestartWarning(); });
     connect(ui->thirdPartyTxUrls, &QLineEdit::textChanged, [this]{ showRestartWarning(); });
 
-    connect(ui->coinJoinEnabled, &QCheckBox::clicked, [=](bool fChecked) {
+    connect(ui->coinJoinEnabled, &QCheckBox::clicked, [this](bool fChecked) {
 #ifdef ENABLE_WALLET
         model->node().coinJoinOptions().setEnabled(fChecked);
 #endif
         updateCoinJoinVisibility();
-        if (_model != nullptr) {
-            _model->emitCoinJoinEnabledChanged();
+        if (this->model != nullptr) {
+            this->model->emitCoinJoinEnabledChanged();
         }
         updateWidth();
     });
@@ -293,7 +293,7 @@ void OptionsDialog::setModel(OptionsModel *_model)
     // Store the current CoinJoin enabled state to recover it if it gets changed but the dialog gets not accepted but declined.
 #ifdef ENABLE_WALLET
     fCoinJoinEnabledPrev = model->node().coinJoinOptions().isEnabled();
-    connect(this, &OptionsDialog::rejected, [=]() {
+    connect(this, &OptionsDialog::rejected, [this]() {
         if (fCoinJoinEnabledPrev != model->node().coinJoinOptions().isEnabled()) {
             ui->coinJoinEnabled->click();
         }
diff --git a/src/qt/overviewpage.cpp b/src/qt/overviewpage.cpp
index 6b9ace3144dff..6f9a92438d48b 100644
--- a/src/qt/overviewpage.cpp
+++ b/src/qt/overviewpage.cpp
@@ -328,7 +328,7 @@ void OverviewPage::setWalletModel(WalletModel *model)
         connect(model->getOptionsModel(), &OptionsModel::coinJoinRoundsChanged, this, &OverviewPage::updateCoinJoinProgress);
         connect(model->getOptionsModel(), &OptionsModel::coinJoinAmountChanged, this, &OverviewPage::updateCoinJoinProgress);
         connect(model->getOptionsModel(), &OptionsModel::AdvancedCJUIChanged, this, &OverviewPage::updateAdvancedCJUI);
-        connect(model->getOptionsModel(), &OptionsModel::coinJoinEnabledChanged, [=]() {
+        connect(model->getOptionsModel(), &OptionsModel::coinJoinEnabledChanged, [this]() {
             coinJoinStatus(true);
         });