diff --git a/build-aux/m4/bitcoin_qt.m4 b/build-aux/m4/bitcoin_qt.m4
index ac697dc2e5ee..b40e77a5f3da 100644
--- a/build-aux/m4/bitcoin_qt.m4
+++ b/build-aux/m4/bitcoin_qt.m4
@@ -53,8 +53,8 @@ dnl CAUTION: Do not use this inside of a conditional.
 AC_DEFUN([BITCOIN_QT_INIT],[
   dnl enable qt support
   AC_ARG_WITH([gui],
-    [AS_HELP_STRING([--with-gui@<:@=no|qt4|qt5|auto@:>@],
-    [build pivx-qt GUI (default=auto, qt5 tried first)])],
+    [AS_HELP_STRING([--with-gui@<:@=no|qt5|auto@:>@],
+    [build pivx-qt GUI (default=auto)])],
     [
      bitcoin_qt_want_version=$withval
      if test "x$bitcoin_qt_want_version" = xyes; then
@@ -94,18 +94,17 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   fi
 
   if test "x$use_pkgconfig" = xyes; then
-    BITCOIN_QT_CHECK([_BITCOIN_QT_FIND_LIBS_WITH_PKGCONFIG([$2])])
+    BITCOIN_QT_CHECK([_BITCOIN_QT_FIND_LIBS_WITH_PKGCONFIG])
   else
     BITCOIN_QT_CHECK([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG])
   fi
 
   dnl This is ugly and complicated. Yuck. Works as follows:
-  dnl We can't discern whether Qt4 builds are static or not. For Qt5, we can
-  dnl check a header to find out. When Qt is built statically, some plugins must
-  dnl be linked into the final binary as well. These plugins have changed between
-  dnl Qt4 and Qt5. With Qt5, languages moved into core and the WindowsIntegration
-  dnl plugin was added. Since we can't tell if Qt4 is static or not, it is
-  dnl assumed for windows builds.
+  dnl For Qt5, we can check a header to find out whether Qt is build
+  dnl statically. When Qt is built statically, some plugins must be linked into
+  dnl the final binary as well.
+  dnl With Qt5, languages moved into core and the WindowsIntegration plugin was
+  dnl added.
   dnl _BITCOIN_QT_CHECK_STATIC_PLUGINS does a quick link-check and appends the
   dnl results to QT_LIBS.
   BITCOIN_QT_CHECK([
@@ -113,54 +112,40 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   TEMP_CXXFLAGS=$CXXFLAGS
   CPPFLAGS="$QT_INCLUDES $CPPFLAGS"
   CXXFLAGS="$PIC_FLAGS $CXXFLAGS"
-  if test "x$bitcoin_qt_got_major_vers" = x5; then
-    TEMP_CPPFLAGS="$TEMP_CPPFLAGS -DHAVE_QT5"
-    _BITCOIN_QT_IS_STATIC
-    if test "x$bitcoin_cv_static_qt" = xyes; then
-      _BITCOIN_QT_FIND_STATIC_PLUGINS
-      AC_DEFINE(QT_STATICPLUGIN, 1, [Define this symbol if qt plugins are static])
-      AC_CACHE_CHECK(for Qt < 5.4, bitcoin_cv_need_acc_widget,[
-        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-            #include <QtCore/qconfig.h>
-            #ifndef QT_VERSION
-            #  include <QtCore/qglobal.h>
-            #endif
-          ]],
-          [[
-            #if QT_VERSION >= 0x050400
-            choke
-            #endif
-          ]])],
-        [bitcoin_cv_need_acc_widget=yes],
-        [bitcoin_cv_need_acc_widget=no])
-      ])
-      if test "x$bitcoin_cv_need_acc_widget" = xyes; then
-        _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(AccessibleFactory)], [-lqtaccessiblewidgets])
-      fi
-      _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QMinimalIntegrationPlugin)],[-lqminimal])
-      AC_DEFINE(QT_QPA_PLATFORM_MINIMAL, 1, [Define this symbol if the minimal qt platform exists])
-      if test "x$TARGET_OS" = xwindows; then
-        _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QWindowsIntegrationPlugin)],[-lqwindows])
-        AC_DEFINE(QT_QPA_PLATFORM_WINDOWS, 1, [Define this symbol if the qt platform is windows])
-      elif test "x$TARGET_OS" = xlinux; then
-        _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QXcbIntegrationPlugin)],[-lqxcb -lxcb-static])
-        AC_DEFINE(QT_QPA_PLATFORM_XCB, 1, [Define this symbol if the qt platform is xcb])
-      elif test "x$TARGET_OS" = xdarwin; then
-        AX_CHECK_LINK_FLAG([[-framework IOKit]],[QT_LIBS="$QT_LIBS -framework IOKit"],[AC_MSG_ERROR(could not iokit framework)])
-        _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QCocoaIntegrationPlugin)],[-lqcocoa])
-        AC_DEFINE(QT_QPA_PLATFORM_COCOA, 1, [Define this symbol if the qt platform is cocoa])
-      fi
+  _BITCOIN_QT_IS_STATIC
+  if test "x$bitcoin_cv_static_qt" = xyes; then
+    _BITCOIN_QT_FIND_STATIC_PLUGINS
+    AC_DEFINE(QT_STATICPLUGIN, 1, [Define this symbol if qt plugins are static])
+    AC_CACHE_CHECK(for Qt < 5.4, bitcoin_cv_need_acc_widget,[
+      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+          #include <QtCore/qconfig.h>
+          #ifndef QT_VERSION
+          #  include <QtCore/qglobal.h>
+          #endif
+        ]],
+        [[
+          #if QT_VERSION >= 0x050400
+          choke
+          #endif
+        ]])],
+      [bitcoin_cv_need_acc_widget=yes],
+      [bitcoin_cv_need_acc_widget=no])
+    ])
+    if test "x$bitcoin_cv_need_acc_widget" = xyes; then
+      _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(AccessibleFactory)], [-lqtaccessiblewidgets])
     fi
-  else
+    _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QMinimalIntegrationPlugin)],[-lqminimal])
+    AC_DEFINE(QT_QPA_PLATFORM_MINIMAL, 1, [Define this symbol if the minimal qt platform exists])
     if test "x$TARGET_OS" = xwindows; then
-      AC_DEFINE(QT_STATICPLUGIN, 1, [Define this symbol if qt plugins are static])
-      _BITCOIN_QT_CHECK_STATIC_PLUGINS([
-         Q_IMPORT_PLUGIN(qcncodecs)
-         Q_IMPORT_PLUGIN(qjpcodecs)
-         Q_IMPORT_PLUGIN(qtwcodecs)
-         Q_IMPORT_PLUGIN(qkrcodecs)
-         Q_IMPORT_PLUGIN(AccessibleFactory)],
-         [-lqcncodecs -lqjpcodecs -lqtwcodecs -lqkrcodecs -lqtaccessiblewidgets])
+      _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QWindowsIntegrationPlugin)],[-lqwindows])
+      AC_DEFINE(QT_QPA_PLATFORM_WINDOWS, 1, [Define this symbol if the qt platform is windows])
+    elif test "x$TARGET_OS" = xlinux; then
+      _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QXcbIntegrationPlugin)],[-lqxcb -lxcb-static])
+      AC_DEFINE(QT_QPA_PLATFORM_XCB, 1, [Define this symbol if the qt platform is xcb])
+    elif test "x$TARGET_OS" = xdarwin; then
+      AX_CHECK_LINK_FLAG([[-framework IOKit]],[QT_LIBS="$QT_LIBS -framework IOKit"],[AC_MSG_ERROR(could not iokit framework)])
+      _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QCocoaIntegrationPlugin)],[-lqcocoa])
+      AC_DEFINE(QT_QPA_PLATFORM_COCOA, 1, [Define this symbol if the qt platform is cocoa])
     fi
   fi
   CPPFLAGS=$TEMP_CPPFLAGS
@@ -168,9 +153,7 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   ])
 
   if test "x$use_pkgconfig$qt_bin_path" = xyes; then
-    if test "x$bitcoin_qt_got_major_vers" = x5; then
-      qt_bin_path="`$PKG_CONFIG --variable=host_bins Qt5Core 2>/dev/null`"
-    fi
+    qt_bin_path="`$PKG_CONFIG --variable=host_bins Qt5Core 2>/dev/null`"
   fi
 
   if test "x$use_hardening" != xno; then
@@ -220,11 +203,11 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
     ])
   fi
 
-  BITCOIN_QT_PATH_PROGS([MOC], [moc-qt${bitcoin_qt_got_major_vers} moc${bitcoin_qt_got_major_vers} moc], $qt_bin_path)
-  BITCOIN_QT_PATH_PROGS([UIC], [uic-qt${bitcoin_qt_got_major_vers} uic${bitcoin_qt_got_major_vers} uic], $qt_bin_path)
-  BITCOIN_QT_PATH_PROGS([RCC], [rcc-qt${bitcoin_qt_got_major_vers} rcc${bitcoin_qt_got_major_vers} rcc], $qt_bin_path)
-  BITCOIN_QT_PATH_PROGS([LRELEASE], [lrelease-qt${bitcoin_qt_got_major_vers} lrelease${bitcoin_qt_got_major_vers} lrelease], $qt_bin_path)
-  BITCOIN_QT_PATH_PROGS([LUPDATE], [lupdate-qt${bitcoin_qt_got_major_vers} lupdate${bitcoin_qt_got_major_vers} lupdate],$qt_bin_path, yes)
+  BITCOIN_QT_PATH_PROGS([MOC], [moc-qt5 moc5 moc], $qt_bin_path)
+  BITCOIN_QT_PATH_PROGS([UIC], [uic-qt5 uic5 uic], $qt_bin_path)
+  BITCOIN_QT_PATH_PROGS([RCC], [rcc-qt5 rcc5 rcc], $qt_bin_path)
+  BITCOIN_QT_PATH_PROGS([LRELEASE], [lrelease-qt5 lrelease5 lrelease], $qt_bin_path)
+  BITCOIN_QT_PATH_PROGS([LUPDATE], [lupdate-qt5 lupdate5 lupdate],$qt_bin_path, yes)
 
   MOC_DEFS='-DHAVE_CONFIG_H -I$(srcdir)'
   case $host in
@@ -263,7 +246,7 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   ],[
     bitcoin_enable_qt=no
   ])
-  AC_MSG_RESULT([$bitcoin_enable_qt (Qt${bitcoin_qt_got_major_vers})])
+  AC_MSG_RESULT([$bitcoin_enable_qt (Qt5)])
 
   AC_SUBST(QT_PIE_FLAGS)
   AC_SUBST(QT_INCLUDES)
@@ -273,7 +256,7 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   AC_SUBST(QT_DBUS_LIBS)
   AC_SUBST(QT_TEST_INCLUDES)
   AC_SUBST(QT_TEST_LIBS)
-  AC_SUBST(QT_SELECT, qt${bitcoin_qt_got_major_vers})
+  AC_SUBST(QT_SELECT, qt5)
   AC_SUBST(MOC_DEFS)
 ])
 
@@ -302,7 +285,7 @@ AC_DEFUN([_BITCOIN_QT_CHECK_QT5],[
 ])])
 
 dnl Internal. Check if the linked version of Qt was built as static libs.
-dnl Requires: Qt5. This check cannot determine if Qt4 is static.
+dnl Requires: Qt5.
 dnl Requires: INCLUDES and LIBS must be populated as necessary.
 dnl Output: bitcoin_cv_static_qt=yes|no
 dnl Output: Defines QT_STATICPLUGIN if plugins are static.
@@ -347,58 +330,50 @@ AC_DEFUN([_BITCOIN_QT_CHECK_STATIC_PLUGINS],[
 ])
 
 dnl Internal. Find paths necessary for linking qt static plugins
-dnl Inputs: bitcoin_qt_got_major_vers. 4 or 5.
 dnl Inputs: qt_plugin_path. optional.
 dnl Outputs: QT_LIBS is appended
 AC_DEFUN([_BITCOIN_QT_FIND_STATIC_PLUGINS],[
-  if test "x$bitcoin_qt_got_major_vers" = x5; then
-      if test "x$qt_plugin_path" != x; then
-        QT_LIBS="$QT_LIBS -L$qt_plugin_path/platforms"
-        if test -d "$qt_plugin_path/accessible"; then
-          QT_LIBS="$QT_LIBS -L$qt_plugin_path/accessible"
-        fi
+    if test "x$qt_plugin_path" != x; then
+      QT_LIBS="$QT_LIBS -L$qt_plugin_path/platforms"
+      if test -d "$qt_plugin_path/accessible"; then
+        QT_LIBS="$QT_LIBS -L$qt_plugin_path/accessible"
       fi
-     if test "x$use_pkgconfig" = xyes; then
-     : dnl
-     m4_ifdef([PKG_CHECK_MODULES],[
-       PKG_CHECK_MODULES([QTPLATFORM], [Qt5PlatformSupport], [QT_LIBS="$QTPLATFORM_LIBS $QT_LIBS"])
-       if test "x$TARGET_OS" = xlinux; then
-         PKG_CHECK_MODULES([X11XCB], [x11-xcb], [QT_LIBS="$X11XCB_LIBS $QT_LIBS"])
-         if ${PKG_CONFIG} --exists "Qt5Core >= 5.5" 2>/dev/null; then
-           PKG_CHECK_MODULES([QTXCBQPA], [Qt5XcbQpa], [QT_LIBS="$QTXCBQPA_LIBS $QT_LIBS"])
-         fi
-       elif test "x$TARGET_OS" = xdarwin; then
-         PKG_CHECK_MODULES([QTPRINT], [Qt5PrintSupport], [QT_LIBS="$QTPRINT_LIBS $QT_LIBS"])
+    fi
+   if test "x$use_pkgconfig" = xyes; then
+   : dnl
+   m4_ifdef([PKG_CHECK_MODULES],[
+     PKG_CHECK_MODULES([QTPLATFORM], [Qt5PlatformSupport], [QT_LIBS="$QTPLATFORM_LIBS $QT_LIBS"])
+     if test "x$TARGET_OS" = xlinux; then
+       PKG_CHECK_MODULES([X11XCB], [x11-xcb], [QT_LIBS="$X11XCB_LIBS $QT_LIBS"])
+       if ${PKG_CONFIG} --exists "Qt5Core >= 5.5" 2>/dev/null; then
+         PKG_CHECK_MODULES([QTXCBQPA], [Qt5XcbQpa], [QT_LIBS="$QTXCBQPA_LIBS $QT_LIBS"])
        fi
-     ])
-     else
-       if test "x$TARGET_OS" = xwindows; then
-         AC_CACHE_CHECK(for Qt >= 5.6, bitcoin_cv_need_platformsupport,[
-           AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-               #include <QtCore/qconfig.h>
-               #ifndef QT_VERSION
-               #  include <QtCore/qglobal.h>
-               #endif
-             ]],
-             [[
-               #if QT_VERSION < 0x050600
-               choke
-               #endif
-             ]])],
-           [bitcoin_cv_need_platformsupport=yes],
-           [bitcoin_cv_need_platformsupport=no])
-         ])
-         if test "x$bitcoin_cv_need_platformsupport" = xyes; then
-           BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}PlatformSupport],[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}PlatformSupport not found)))
-         fi
+     elif test "x$TARGET_OS" = xdarwin; then
+       PKG_CHECK_MODULES([QTPRINT], [Qt5PrintSupport], [QT_LIBS="$QTPRINT_LIBS $QT_LIBS"])
+     fi
+   ])
+   else
+     if test "x$TARGET_OS" = xwindows; then
+       AC_CACHE_CHECK(for Qt >= 5.6, bitcoin_cv_need_platformsupport,[
+         AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+             #include <QtCore/qconfig.h>
+             #ifndef QT_VERSION
+             #  include <QtCore/qglobal.h>
+             #endif
+           ]],
+           [[
+             #if QT_VERSION < 0x050600
+             choke
+             #endif
+           ]])],
+         [bitcoin_cv_need_platformsupport=yes],
+         [bitcoin_cv_need_platformsupport=no])
+       ])
+       if test "x$bitcoin_cv_need_platformsupport" = xyes; then
+         BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}PlatformSupport],[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}PlatformSupport not found)))
        fi
      fi
-  else
-    if test "x$qt_plugin_path" != x; then
-      QT_LIBS="$QT_LIBS -L$qt_plugin_path/accessible"
-      QT_LIBS="$QT_LIBS -L$qt_plugin_path/codecs"
-    fi
-  fi
+   fi
 ])
 
 dnl Internal. Find Qt libraries using pkg-config.
@@ -407,38 +382,14 @@ dnl         first.
 dnl Inputs: $1: If bitcoin_qt_want_version is "auto", check for this version
 dnl         first.
 dnl Outputs: All necessary QT_* variables are set.
-dnl Outputs: bitcoin_qt_got_major_vers is set to "4" or "5".
 dnl Outputs: have_qt_test and have_qt_dbus are set (if applicable) to yes|no.
 AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITH_PKGCONFIG],[
   m4_ifdef([PKG_CHECK_MODULES],[
-  auto_priority_version=$1
-  if test "x$auto_priority_version" = x; then
-    auto_priority_version=qt5
-  fi
-    if test "x$bitcoin_qt_want_version" = xqt5 ||  ( test "x$bitcoin_qt_want_version" = xauto && test "x$auto_priority_version" = xqt5 ); then
-      QT_LIB_PREFIX=Qt5
-      bitcoin_qt_got_major_vers=5
-    else
-      QT_LIB_PREFIX=Qt
-      bitcoin_qt_got_major_vers=4
-    fi
+    QT_LIB_PREFIX=Qt5
     qt5_modules="Qt5Core Qt5Gui Qt5Network Qt5Widgets"
-    qt4_modules="QtCore QtGui QtNetwork"
     BITCOIN_QT_CHECK([
-      if test "x$bitcoin_qt_want_version" = xqt5 || ( test "x$bitcoin_qt_want_version" = xauto && test "x$auto_priority_version" = xqt5 ); then
-        PKG_CHECK_MODULES([QT5], [$qt5_modules], [QT_INCLUDES="$QT5_CFLAGS"; QT_LIBS="$QT5_LIBS" have_qt=yes],[have_qt=no])
-      elif test "x$bitcoin_qt_want_version" = xqt4 || ( test "x$bitcoin_qt_want_version" = xauto && test "x$auto_priority_version" = xqt4 ); then
-        PKG_CHECK_MODULES([QT4], [$qt4_modules], [QT_INCLUDES="$QT4_CFLAGS"; QT_LIBS="$QT4_LIBS" ; have_qt=yes], [have_qt=no])
-      fi
+      PKG_CHECK_MODULES([QT5], [$qt5_modules], [QT_INCLUDES="$QT5_CFLAGS"; QT_LIBS="$QT5_LIBS" have_qt=yes],[have_qt=no])
 
-      dnl qt version is set to 'auto' and the preferred version wasn't found. Now try the other.
-      if test "x$have_qt" = xno && test "x$bitcoin_qt_want_version" = xauto; then
-        if test "x$auto_priority_version" = xqt5; then
-          PKG_CHECK_MODULES([QT4], [$qt4_modules], [QT_INCLUDES="$QT4_CFLAGS"; QT_LIBS="$QT4_LIBS" ; have_qt=yes; QT_LIB_PREFIX=Qt; bitcoin_qt_got_major_vers=4], [have_qt=no])
-        else
-          PKG_CHECK_MODULES([QT5], [$qt5_modules], [QT_INCLUDES="$QT5_CFLAGS"; QT_LIBS="$QT5_LIBS" ; have_qt=yes; QT_LIB_PREFIX=Qt5; bitcoin_qt_got_major_vers=5], [have_qt=no])
-        fi
-      fi
       if test "x$have_qt" != xyes; then
         have_qt=no
         BITCOIN_QT_FAIL([Qt dependencies not found])
@@ -459,7 +410,6 @@ dnl from the discovered headers.
 dnl Inputs: bitcoin_qt_want_version (from --with-gui=). The version to use.
 dnl         If "auto", the version will be discovered by _BITCOIN_QT_CHECK_QT5.
 dnl Outputs: All necessary QT_* variables are set.
-dnl Outputs: bitcoin_qt_got_major_vers is set to "4" or "5".
 dnl Outputs: have_qt_test and have_qt_dbus are set (if applicable) to yes|no.
 AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG],[
   TEMP_CPPFLAGS="$CPPFLAGS"
@@ -481,13 +431,7 @@ AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG],[
     if test "x$bitcoin_qt_want_version" = xauto; then
       _BITCOIN_QT_CHECK_QT5
     fi
-    if test "x$bitcoin_cv_qt5" = xyes || test "x$bitcoin_qt_want_version" = xqt5; then
-      QT_LIB_PREFIX=Qt5
-      bitcoin_qt_got_major_vers=5
-    else
-      QT_LIB_PREFIX=Qt
-      bitcoin_qt_got_major_vers=4
-    fi
+    QT_LIB_PREFIX=Qt5
   ])
 
   BITCOIN_QT_CHECK([
@@ -509,9 +453,7 @@ AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG],[
   BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Core]   ,[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}Core not found)))
   BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Gui]    ,[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}Gui not found)))
   BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Network],[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}Network not found)))
-  if test "x$bitcoin_qt_got_major_vers" = x5; then
-    BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Widgets],[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}Widgets not found)))
-  fi
+  BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Widgets],[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}Widgets not found)))
   QT_LIBS="$LIBS"
   LIBS="$TEMP_LIBS"
 
diff --git a/configure.ac b/configure.ac
index 9a66a2d557c9..2b8f95a7ecf8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -682,7 +682,7 @@ fi
 BITCOIN_QT_INIT
 
 dnl sets $bitcoin_enable_qt, $bitcoin_enable_qt_test, $bitcoin_enable_qt_dbus
-BITCOIN_QT_CONFIGURE([$use_pkgconfig], [qt5])
+BITCOIN_QT_CONFIGURE([$use_pkgconfig])
 
 if test x$build_bitcoin_utils$build_bitcoind$bitcoin_enable_qt$use_tests = xnononono; then
     use_boost=no
@@ -1243,7 +1243,6 @@ echo "Options used to compile and link:"
 echo "  with wallet   = $enable_wallet"
 echo "  with gui / qt = $bitcoin_enable_qt"
 if test x$bitcoin_enable_qt != xno; then
-    echo "    qt version  = $bitcoin_qt_got_major_vers"
     echo "    with qr     = $use_qr"
 fi
 echo "  with zmq      = $use_zmq"
diff --git a/src/qt/addressbookpage.cpp b/src/qt/addressbookpage.cpp
index a172fa5a46ef..6d27e1846346 100644
--- a/src/qt/addressbookpage.cpp
+++ b/src/qt/addressbookpage.cpp
@@ -132,14 +132,9 @@ void AddressBookPage::setModel(AddressTableModel* model)
     ui->tableView->setModel(proxyModel);
     ui->tableView->sortByColumn(0, Qt::AscendingOrder);
 
-// Set column widths
-#if QT_VERSION < 0x050000
-    ui->tableView->horizontalHeader()->setResizeMode(AddressTableModel::Label, QHeaderView::Stretch);
-    ui->tableView->horizontalHeader()->setResizeMode(AddressTableModel::Address, QHeaderView::ResizeToContents);
-#else
+    // Set column widths
     ui->tableView->horizontalHeader()->setSectionResizeMode(AddressTableModel::Label, QHeaderView::Stretch);
     ui->tableView->horizontalHeader()->setSectionResizeMode(AddressTableModel::Address, QHeaderView::ResizeToContents);
-#endif
 
     connect(ui->tableView->selectionModel(), SIGNAL(selectionChanged(QItemSelection, QItemSelection)),
         this, SLOT(selectionChanged()));
diff --git a/src/qt/bantablemodel.cpp b/src/qt/bantablemodel.cpp
index 679f3a2086cd..5bc703d06aee 100644
--- a/src/qt/bantablemodel.cpp
+++ b/src/qt/bantablemodel.cpp
@@ -52,9 +52,7 @@ class BanTablePriv
         CNode::GetBanned(banMap);
 
         cachedBanlist.clear();
-#if QT_VERSION >= 0x040700
         cachedBanlist.reserve(banMap.size());
-#endif
         for (banmap_t::iterator it = banMap.begin(); it != banMap.end(); it++)
         {
             CCombinedBan banEntry;
diff --git a/src/qt/bip38tooldialog.cpp b/src/qt/bip38tooldialog.cpp
index f6fa8f36b537..2182ee36b13f 100644
--- a/src/qt/bip38tooldialog.cpp
+++ b/src/qt/bip38tooldialog.cpp
@@ -26,9 +26,7 @@ Bip38ToolDialog::Bip38ToolDialog(QWidget* parent) : QDialog(parent, Qt::WindowSy
 {
     ui->setupUi(this);
 
-#if QT_VERSION >= 0x040700
     ui->decryptedKeyOut_DEC->setPlaceholderText(tr("Click \"Decrypt Key\" to compute key"));
-#endif
 
     GUIUtil::setupAddressWidget(ui->addressIn_ENC, this);
     ui->addressIn_ENC->installEventFilter(this);
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index 3da95816295d..db6aa5b5f341 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -54,14 +54,8 @@
 #include <QStyle>
 #include <QTimer>
 #include <QToolBar>
-#include <QVBoxLayout>
-
-#if QT_VERSION < 0x050000
-#include <QTextDocument>
-#include <QUrl>
-#else
 #include <QUrlQuery>
-#endif
+#include <QVBoxLayout>
 
 const QString BitcoinGUI::DEFAULT_WALLET = "~Default";
 
@@ -140,12 +134,6 @@ BitcoinGUI::BitcoinGUI(const NetworkStyle* networkStyle, QWidget* parent) : QMai
 #endif
     setWindowTitle(windowTitle);
 
-#if defined(Q_OS_MAC) && QT_VERSION < 0x050000
-    // This property is not implemented in Qt 5. Setting it has no effect.
-    // A replacement API (QtMacUnifiedToolBar) is available in QtMacExtras.
-    setUnifiedTitleAndToolBarOnMac(true);
-#endif
-
     rpcConsole = new RPCConsole(enableWallet ? this : 0);
 #ifdef ENABLE_WALLET
     if (enableWallet) {
@@ -235,7 +223,7 @@ BitcoinGUI::BitcoinGUI(const NetworkStyle* networkStyle, QWidget* parent) : QMai
 
     // Override style sheet for progress bar for styles that have a segmented progress bar,
     // as they make the text unreadable (workaround for issue #1071)
-    // See https://qt-project.org/doc/qt-4.8/gallery.html
+    // See https://doc.qt.io/qt-5/gallery.html
     QString curStyle = QApplication::style()->metaObject()->className();
     if (curStyle == "QWindowsStyle" || curStyle == "QWindowsXPStyle") {
         progressBar->setStyleSheet("QProgressBar { background-color: #F8F8F8; border: 1px solid grey; border-radius: 7px; padding: 1px; text-align: center; } QProgressBar::chunk { background: QLinearGradient(x1: 0, y1: 0, x2: 1, y2: 0, stop: 0 #00CCFF, stop: 1 #33CCFF); border-radius: 7px; margin: 0px; }");
@@ -401,11 +389,7 @@ void BitcoinGUI::createActions(const NetworkStyle* networkStyle)
     aboutAction = new QAction(networkStyle->getAppIcon(), tr("&About PIVX Core"), this);
     aboutAction->setStatusTip(tr("Show information about PIVX Core"));
     aboutAction->setMenuRole(QAction::AboutRole);
-#if QT_VERSION < 0x050000
-    aboutQtAction = new QAction(QIcon(":/trolltech/qmessagebox/images/qtlogo-64.png"), tr("About &Qt"), this);
-#else
     aboutQtAction = new QAction(QIcon(":/qt-project.org/qmessagebox/images/qtlogo-64.png"), tr("About &Qt"), this);
-#endif
     aboutQtAction->setStatusTip(tr("Show information about Qt"));
     aboutQtAction->setMenuRole(QAction::AboutQtRole);
     optionsAction = new QAction(QIcon(":/icons/options"), tr("&Options..."), this);
diff --git a/src/qt/coincontroldialog.cpp b/src/qt/coincontroldialog.cpp
index ce9e175c70fa..068414cd93eb 100644
--- a/src/qt/coincontroldialog.cpp
+++ b/src/qt/coincontroldialog.cpp
@@ -110,12 +110,8 @@ CoinControlDialog::CoinControlDialog(QWidget* parent, bool fMultisigEnabled) : Q
     // click on checkbox
     connect(ui->treeWidget, SIGNAL(itemChanged(QTreeWidgetItem*, int)), this, SLOT(viewItemChanged(QTreeWidgetItem*, int)));
 
-// click on header
-#if QT_VERSION < 0x050000
-    ui->treeWidget->header()->setClickable(true);
-#else
+    // click on header
     ui->treeWidget->header()->setSectionsClickable(true);
-#endif
     connect(ui->treeWidget->header(), SIGNAL(sectionClicked(int)), this, SLOT(headerSectionClicked(int)));
 
     // ok button
@@ -445,16 +441,14 @@ void CoinControlDialog::viewItemChanged(QTreeWidgetItem* item, int column)
             updateDialogLabels();
         }
     }
-// todo: this is a temporary qt5 fix: when clicking a parent node in tree mode, the parent node
-//       including all childs are partially selected. But the parent node should be fully selected
-//       as well as the childs. Childs should never be partially selected in the first place.
-//       Please remove this ugly fix, once the bug is solved upstream.
-#if QT_VERSION >= 0x050000
-    else if (column == COLUMN_CHECKBOX && item->childCount() > 0) {
+
+    // TODO: Remove this temporary qt5 fix after Qt5.3 and Qt5.4 are no longer used.
+    //       Fixed in Qt5.5 and above: https://bugreports.qt.io/browse/QTBUG-43473
+    else if (column == COLUMN_CHECKBOX && item->childCount() > 0)
+    {
         if (item->checkState(COLUMN_CHECKBOX) == Qt::PartiallyChecked && item->child(0)->checkState(COLUMN_CHECKBOX) == Qt::PartiallyChecked)
             item->setCheckState(COLUMN_CHECKBOX, Qt::Checked);
     }
-#endif
 }
 
 // return human readable label for priority number
diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
index 384636188d19..bb0fe86fd1f0 100644
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -56,12 +56,9 @@
 #include <QSettings>
 #include <QTextDocument> // for Qt::mightBeRichText
 #include <QThread>
-
-#if QT_VERSION < 0x050000
-#include <QUrl>
-#else
 #include <QUrlQuery>
-#endif
+#include <QMouseEvent>
+
 
 #if BOOST_FILESYSTEM_VERSION >= 3
 static boost::filesystem::detail::utf8_codecvt_facet utf8;
@@ -94,11 +91,7 @@ QString dateTimeStr(qint64 nTime)
 QFont bitcoinAddressFont()
 {
     QFont font("Monospace");
-#if QT_VERSION >= 0x040800
     font.setStyleHint(QFont::Monospace);
-#else
-    font.setStyleHint(QFont::TypeWriter);
-#endif
     return font;
 }
 
@@ -107,11 +100,9 @@ void setupAddressWidget(QValidatedLineEdit* widget, QWidget* parent)
     parent->setFocusProxy(widget);
 
     widget->setFont(bitcoinAddressFont());
-#if QT_VERSION >= 0x040700
     // We don't want translators to use own addresses in translations
     // and this is the only place, where this address is supplied.
     widget->setPlaceholderText(QObject::tr("Enter a PIVX address (e.g. %1)").arg("D7VFR83SQbiezrW72hjcWJtcfip5krte2Z"));
-#endif
     widget->setValidator(new BitcoinAddressEntryValidator(parent));
     widget->setCheckValidator(new BitcoinAddressCheckValidator(parent));
 }
@@ -139,13 +130,10 @@ bool parseBitcoinURI(const QUrl& uri, SendCoinsRecipient* out)
     }
     rv.amount = 0;
 
-#if QT_VERSION < 0x050000
-    QList<QPair<QString, QString> > items = uri.queryItems();
-#else
     QUrlQuery uriQuery(uri);
     QList<QPair<QString, QString> > items = uriQuery.queryItems();
-#endif
-    for (QList<QPair<QString, QString> >::iterator i = items.begin(); i != items.end(); i++) {
+    for (QList<QPair<QString, QString> >::iterator i = items.begin(); i != items.end(); i++)
+    {
         bool fShouldReturnFalse = false;
         if (i->first.startsWith("req-")) {
             i->first.remove(0, 4);
@@ -225,11 +213,7 @@ bool isDust(const QString& address, const CAmount& amount)
 
 QString HtmlEscape(const QString& str, bool fMultiLine)
 {
-#if QT_VERSION < 0x050000
-    QString escaped = Qt::escape(str);
-#else
     QString escaped = str.toHtmlEscaped();
-#endif
     escaped = escaped.replace(" ", "&nbsp;");
     if (fMultiLine) {
         escaped = escaped.replace("\n", "<br>\n");
@@ -273,12 +257,10 @@ QString getSaveFileName(QWidget* parent, const QString& caption, const QString&
     QString myDir;
     if (dir.isEmpty()) // Default to user documents location
     {
-#if QT_VERSION < 0x050000
-        myDir = QDesktopServices::storageLocation(QDesktopServices::DocumentsLocation);
-#else
         myDir = QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation);
-#endif
-    } else {
+    }
+    else
+    {
         myDir = dir;
     }
     /* Directly convert path to native OS path separators */
@@ -315,12 +297,10 @@ QString getOpenFileName(QWidget* parent, const QString& caption, const QString&
     QString myDir;
     if (dir.isEmpty()) // Default to user documents location
     {
-#if QT_VERSION < 0x050000
-        myDir = QDesktopServices::storageLocation(QDesktopServices::DocumentsLocation);
-#else
         myDir = QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation);
-#endif
-    } else {
+    }
+    else
+    {
         myDir = dir;
     }
     /* Directly convert path to native OS path separators */
@@ -470,11 +450,7 @@ void TableViewLastColumnResizingFixer::disconnectViewHeadersSignals()
 // Refactored here for readability.
 void TableViewLastColumnResizingFixer::setViewHeaderResizeMode(int logicalIndex, QHeaderView::ResizeMode resizeMode)
 {
-#if QT_VERSION < 0x050000
-    tableView->horizontalHeader()->setResizeMode(logicalIndex, resizeMode);
-#else
     tableView->horizontalHeader()->setSectionResizeMode(logicalIndex, resizeMode);
-#endif
 }
 
 void TableViewLastColumnResizingFixer::resizeColumn(int nColumnIndex, int width)
diff --git a/src/qt/guiutil.h b/src/qt/guiutil.h
index 69bdb956bf8d..e52867ab0395 100644
--- a/src/qt/guiutil.h
+++ b/src/qt/guiutil.h
@@ -228,19 +228,18 @@ QString formatPingTime(double dPingTime);
 /* Format a CNodeCombinedStats.nTimeOffset into a user-readable string. */
 QString formatTimeOffset(int64_t nTimeOffset);
 
-#if defined(Q_OS_MAC) && QT_VERSION >= 0x050000
-// workaround for Qt OSX Bug:
-// https://bugreports.qt-project.org/browse/QTBUG-15631
-// QProgressBar uses around 10% CPU even when app is in background
-class ProgressBar : public QProgressBar
-{
-    bool event(QEvent* e)
+#if defined(Q_OS_MAC)
+    // workaround for Qt OSX Bug:
+    // https://bugreports.qt-project.org/browse/QTBUG-15631
+    // QProgressBar uses around 10% CPU even when app is in background
+    class ProgressBar : public QProgressBar
     {
-        return (e->type() != QEvent::StyleAnimationUpdate) ? QProgressBar::event(e) : false;
-    }
-};
+        bool event(QEvent *e) {
+            return (e->type() != QEvent::StyleAnimationUpdate) ? QProgressBar::event(e) : false;
+        }
+    };
 #else
-typedef QProgressBar ProgressBar;
+    typedef QProgressBar ProgressBar;
 #endif
 
 } // namespace GUIUtil
diff --git a/src/qt/macdockiconhandler.mm b/src/qt/macdockiconhandler.mm
index e66154f144f8..19d83fc75265 100644
--- a/src/qt/macdockiconhandler.mm
+++ b/src/qt/macdockiconhandler.mm
@@ -14,18 +14,14 @@
 #include <objc/objc.h>
 #include <objc/message.h>
 
-#if QT_VERSION < 0x050000
-extern void qt_mac_set_dock_menu(QMenu *);
-#endif
-
-static MacDockIconHandler *s_instance = NULL;
+static MacDockIconHandler *s_instance = nullptr;
 
 bool dockClickHandler(id self,SEL _cmd,...) {
     Q_UNUSED(self)
     Q_UNUSED(_cmd)
-    
+
     s_instance->handleDockIconClickEvent();
-    
+
     // Return NO (false) to suppress the default OS X actions
     return false;
 }
@@ -33,7 +29,7 @@ bool dockClickHandler(id self,SEL _cmd,...) {
 void setupDockClickHandler() {
     Class cls = objc_getClass("NSApplication");
     id appInst = objc_msgSend((id)cls, sel_registerName("sharedApplication"));
-    
+
     if (appInst != NULL) {
         id delegate = objc_msgSend(appInst, sel_registerName("delegate"));
         Class delClass = (Class)objc_msgSend(delegate,  sel_registerName("class"));
@@ -53,10 +49,8 @@ void setupDockClickHandler() {
     setupDockClickHandler();
     this->m_dummyWidget = new QWidget();
     this->m_dockMenu = new QMenu(this->m_dummyWidget);
-    this->setMainWindow(NULL);
-#if QT_VERSION < 0x050000
-    qt_mac_set_dock_menu(this->m_dockMenu);
-#elif QT_VERSION >= 0x050200
+    this->setMainWindow(nullptr);
+#if QT_VERSION >= 0x050200
     this->m_dockMenu->setAsDockMenu();
 #endif
     [pool release];
diff --git a/src/qt/openuridialog.cpp b/src/qt/openuridialog.cpp
index 90b9a69f6e75..4e5c04b22f3d 100644
--- a/src/qt/openuridialog.cpp
+++ b/src/qt/openuridialog.cpp
@@ -16,9 +16,7 @@ OpenURIDialog::OpenURIDialog(QWidget* parent) : QDialog(parent, Qt::WindowSystem
                                                 ui(new Ui::OpenURIDialog)
 {
     ui->setupUi(this);
-#if QT_VERSION >= 0x040700
     ui->uriEdit->setPlaceholderText("pivx:");
-#endif
 }
 
 OpenURIDialog::~OpenURIDialog()
diff --git a/src/qt/optionsdialog.cpp b/src/qt/optionsdialog.cpp
index bcbb10b54150..87d9fcf09bc8 100644
--- a/src/qt/optionsdialog.cpp
+++ b/src/qt/optionsdialog.cpp
@@ -81,7 +81,7 @@ OptionsDialog::OptionsDialog(QWidget* parent, bool enableWallet) : QDialog(paren
         digits.setNum(index);
         ui->digits->addItem(digits, digits);
     }
-    
+
     /* Theme selector static themes */
     ui->theme->addItem(QString("Default"), QVariant("default"));
 
@@ -114,27 +114,18 @@ OptionsDialog::OptionsDialog(QWidget* parent, bool enableWallet) : QDialog(paren
         QLocale locale(langStr);
 
         /** check if the locale name consists of 2 parts (language_country) */
-        if (langStr.contains("_")) {
-#if QT_VERSION >= 0x040800
+        if(langStr.contains("_"))
+        {
             /** display language strings as "native language - native country (locale name)", e.g. "Deutsch - Deutschland (de)" */
             ui->lang->addItem(locale.nativeLanguageName() + QString(" - ") + locale.nativeCountryName() + QString(" (") + langStr + QString(")"), QVariant(langStr));
-#else
-            /** display language strings as "language - country (locale name)", e.g. "German - Germany (de)" */
-            ui->lang->addItem(QLocale::languageToString(locale.language()) + QString(" - ") + QLocale::countryToString(locale.country()) + QString(" (") + langStr + QString(")"), QVariant(langStr));
-#endif
-        } else {
-#if QT_VERSION >= 0x040800
+        }
+        else
+        {
             /** display language strings as "native language (locale name)", e.g. "Deutsch (de)" */
             ui->lang->addItem(locale.nativeLanguageName() + QString(" (") + langStr + QString(")"), QVariant(langStr));
-#else
-            /** display language strings as "language (locale name)", e.g. "German (de)" */
-            ui->lang->addItem(QLocale::languageToString(locale.language()) + QString(" (") + langStr + QString(")"), QVariant(langStr));
-#endif
         }
     }
-#if QT_VERSION >= 0x040700
     ui->thirdPartyTxUrls->setPlaceholderText("https://example.com/tx/%s");
-#endif
 
     ui->unit->setModel(new BitcoinUnits(this));
 
diff --git a/src/qt/paymentrequestplus.cpp b/src/qt/paymentrequestplus.cpp
index b3a6da4ae21a..35a565dec735 100644
--- a/src/qt/paymentrequestplus.cpp
+++ b/src/qt/paymentrequestplus.cpp
@@ -101,14 +101,12 @@ bool PaymentRequestPlus::getMerchant(X509_STORE* certStore, QString& merchant) c
             qWarning() << "PaymentRequestPlus::getMerchant : Payment request: certificate expired or not yet active: " << qCert;
             return false;
         }
-#if QT_VERSION >= 0x050000
         if (qCert.isBlacklisted()) {
             qWarning() << "PaymentRequestPlus::getMerchant : Payment request: certificate blacklisted: " << qCert;
             return false;
         }
-#endif
-        const unsigned char* data = (const unsigned char*)certChain.certificate(i).data();
-        X509* cert = d2i_X509(NULL, &data, certChain.certificate(i).size());
+        const unsigned char *data = (const unsigned char *)certChain.certificate(i).data();
+        X509 *cert = d2i_X509(nullptr, &data, certChain.certificate(i).size());
         if (cert)
             certs.push_back(cert);
     }
diff --git a/src/qt/paymentserver.cpp b/src/qt/paymentserver.cpp
index 931faeb7fda8..23a7badab1e9 100644
--- a/src/qt/paymentserver.cpp
+++ b/src/qt/paymentserver.cpp
@@ -41,12 +41,7 @@
 #include <QSslSocket>
 #include <QStringList>
 #include <QTextDocument>
-
-#if QT_VERSION < 0x050000
-#include <QUrl>
-#else
 #include <QUrlQuery>
-#endif
 
 using namespace boost;
 using namespace std;
@@ -106,7 +101,7 @@ static QList<QString> savedPaymentRequests;
 
 static void ReportInvalidCertificate(const QSslCertificate& cert)
 {
-    qDebug() << "ReportInvalidCertificate : Payment server found an invalid certificate: " << cert.subjectInfo(QSslCertificate::CommonName);
+    qDebug() << QString("%1: Payment server found an invalid certificate: ").arg(__func__) << cert.serialNumber() << cert.subjectInfo(QSslCertificate::CommonName) << cert.subjectInfo(QSslCertificate::DistinguishedNameQualifier) << cert.subjectInfo(QSslCertificate::OrganizationalUnitName);
 }
 
 //
@@ -146,12 +141,12 @@ void PaymentServer::LoadRootCAs(X509_STORE* _store)
             ReportInvalidCertificate(cert);
             continue;
         }
-#if QT_VERSION >= 0x050000
+
+        // Blacklisted certificate
         if (cert.isBlacklisted()) {
             ReportInvalidCertificate(cert);
             continue;
         }
-#endif
         QByteArray certData = cert.toDer();
         const unsigned char* data = (const unsigned char*)certData.data();
 
@@ -374,11 +369,7 @@ void PaymentServer::handleURIOrFile(const QString& s)
 
     if (s.startsWith(BITCOIN_IPC_PREFIX, Qt::CaseInsensitive)) // pivx: URI
     {
-#if QT_VERSION < 0x050000
-        QUrl uri(s);
-#else
         QUrlQuery uri((QUrl(s)));
-#endif
         if (uri.hasQueryItem("r")) // payment request URI
         {
             QByteArray temp;
diff --git a/src/qt/peertablemodel.cpp b/src/qt/peertablemodel.cpp
index 07331351f2b0..0a6f38b93f85 100644
--- a/src/qt/peertablemodel.cpp
+++ b/src/qt/peertablemodel.cpp
@@ -59,9 +59,8 @@ class PeerTablePriv
                 return;
             }
             cachedNodeStats.clear();
-#if QT_VERSION >= 0x040700
+
             cachedNodeStats.reserve(vNodes.size());
-#endif
             foreach (CNode* pnode, vNodes) {
                 CNodeCombinedStats stats;
                 stats.nodeStateStats.nMisbehavior = 0;
diff --git a/src/qt/pivx.cpp b/src/qt/pivx.cpp
index dfd3b68e14eb..85d03ce7602d 100644
--- a/src/qt/pivx.cpp
+++ b/src/qt/pivx.cpp
@@ -56,13 +56,6 @@
 
 #if defined(QT_STATICPLUGIN)
 #include <QtPlugin>
-#if QT_VERSION < 0x050000
-Q_IMPORT_PLUGIN(qcncodecs)
-Q_IMPORT_PLUGIN(qjpcodecs)
-Q_IMPORT_PLUGIN(qtwcodecs)
-Q_IMPORT_PLUGIN(qkrcodecs)
-Q_IMPORT_PLUGIN(qtaccessiblewidgets)
-#else
 #if QT_VERSION < 0x050400
 Q_IMPORT_PLUGIN(AccessibleFactory)
 #endif
@@ -74,11 +67,6 @@ Q_IMPORT_PLUGIN(QWindowsIntegrationPlugin);
 Q_IMPORT_PLUGIN(QCocoaIntegrationPlugin);
 #endif
 #endif
-#endif
-
-#if QT_VERSION < 0x050000
-#include <QTextCodec>
-#endif
 
 // Declare meta types used for QMetaObject::invokeMethod
 Q_DECLARE_METATYPE(bool*)
@@ -151,20 +139,12 @@ static void initTranslations(QTranslator& qtTranslatorBase, QTranslator& qtTrans
 }
 
 /* qDebug() message handler --> debug.log */
-#if QT_VERSION < 0x050000
-void DebugMessageHandler(QtMsgType type, const char* msg)
-{
-    const char* category = (type == QtDebugMsg) ? "qt" : NULL;
-    LogPrint(category, "GUI: %s\n", msg);
-}
-#else
 void DebugMessageHandler(QtMsgType type, const QMessageLogContext& context, const QString& msg)
 {
     Q_UNUSED(context);
     const char* category = (type == QtDebugMsg) ? "qt" : NULL;
     LogPrint(category, "GUI: %s\n", msg.toStdString());
 }
-#endif
 
 /** Class encapsulating PIVX Core startup and shutdown.
  * Allows running startup and shutdown in a different thread from the UI thread.
@@ -525,12 +505,6 @@ int main(int argc, char* argv[])
 // Do not refer to data directory yet, this can be overridden by Intro::pickDataDirectory
 
 /// 2. Basic Qt initialization (not dependent on parameters or configuration)
-#if QT_VERSION < 0x050000
-    // Internal string conversion is all UTF-8
-    QTextCodec::setCodecForTr(QTextCodec::codecForName("UTF-8"));
-    QTextCodec::setCodecForCStrings(QTextCodec::codecForTr());
-#endif
-
     Q_INIT_RESOURCE(pivx_locale);
     Q_INIT_RESOURCE(pivx);
 
@@ -643,17 +617,12 @@ int main(int argc, char* argv[])
     /// 9. Main GUI initialization
     // Install global event filter that makes sure that long tooltips can be word-wrapped
     app.installEventFilter(new GUIUtil::ToolTipToRichTextFilter(TOOLTIP_WRAP_THRESHOLD, &app));
-#if QT_VERSION < 0x050000
-    // Install qDebug() message handler to route to debug.log
-    qInstallMsgHandler(DebugMessageHandler);
-#else
 #if defined(Q_OS_WIN)
     // Install global event filter for processing Windows session related Windows messages (WM_QUERYENDSESSION and WM_ENDSESSION)
     qApp->installNativeEventFilter(new WinShutdownMonitor());
 #endif
     // Install qDebug() message handler to route to debug.log
     qInstallMessageHandler(DebugMessageHandler);
-#endif
     // Load GUI settings from QSettings
     app.createOptionsModel();
 
@@ -666,7 +635,7 @@ int main(int argc, char* argv[])
     try {
         app.createWindow(networkStyle.data());
         app.requestInitialize();
-#if defined(Q_OS_WIN) && QT_VERSION >= 0x050000
+#if defined(Q_OS_WIN)
         WinShutdownMonitor::registerShutdownBlockReason(QObject::tr("PIVX Core didn't yet exit safely..."), (HWND)app.getMainWinId());
 #endif
         app.exec();
diff --git a/src/qt/receiverequestdialog.cpp b/src/qt/receiverequestdialog.cpp
index 2048294b15dc..3ffe6f0e997b 100644
--- a/src/qt/receiverequestdialog.cpp
+++ b/src/qt/receiverequestdialog.cpp
@@ -18,9 +18,6 @@
 #include <QMimeData>
 #include <QMouseEvent>
 #include <QPixmap>
-#if QT_VERSION < 0x050000
-#include <QUrl>
-#endif
 
 #if defined(HAVE_CONFIG_H)
 #include "config/pivx-config.h" /* for USE_QRCODE */
diff --git a/src/qt/rpcconsole.cpp b/src/qt/rpcconsole.cpp
index 296248ccc5d6..e93999d31649 100644
--- a/src/qt/rpcconsole.cpp
+++ b/src/qt/rpcconsole.cpp
@@ -39,10 +39,6 @@
 #include <QTimer>
 #include <QStringList>
 
-#if QT_VERSION < 0x050000
-#include <QUrl>
-#endif
-
 // TODO: add a scrollback limit, as there is currently none
 // TODO: make it possible to filter out categories (esp debug messages when implemented)
 // TODO: receive errors and debug messages through ClientModel
diff --git a/src/qt/sendcoinsentry.cpp b/src/qt/sendcoinsentry.cpp
index f93b2212c33e..57de4c5c53dc 100644
--- a/src/qt/sendcoinsentry.cpp
+++ b/src/qt/sendcoinsentry.cpp
@@ -27,9 +27,7 @@ SendCoinsEntry::SendCoinsEntry(QWidget* parent) : QStackedWidget(parent),
 #ifdef Q_OS_MAC
     ui->payToLayout->setSpacing(4);
 #endif
-#if QT_VERSION >= 0x040700
     ui->addAsLabel->setPlaceholderText(tr("Enter a label for this address to add it to your address book"));
-#endif
 
     // normal pivx address field
     GUIUtil::setupAddressWidget(ui->payTo, this);
diff --git a/src/qt/signverifymessagedialog.cpp b/src/qt/signverifymessagedialog.cpp
index 5d5c3ce954a4..8c46ce3f6703 100644
--- a/src/qt/signverifymessagedialog.cpp
+++ b/src/qt/signverifymessagedialog.cpp
@@ -27,9 +27,7 @@ SignVerifyMessageDialog::SignVerifyMessageDialog(QWidget* parent) : QDialog(pare
 {
     ui->setupUi(this);
 
-#if QT_VERSION >= 0x040700
     ui->signatureOut_SM->setPlaceholderText(tr("Click \"Sign Message\" to generate signature"));
-#endif
 
     GUIUtil::setupAddressWidget(ui->addressIn_SM, this);
     GUIUtil::setupAddressWidget(ui->addressIn_VM, this);
diff --git a/src/qt/test/test_main.cpp b/src/qt/test/test_main.cpp
index 2295a67e7811..0cfcf6fd7467 100644
--- a/src/qt/test/test_main.cpp
+++ b/src/qt/test/test_main.cpp
@@ -21,13 +21,21 @@
 
 #include <openssl/ssl.h>
 
-#if defined(QT_STATICPLUGIN) && QT_VERSION < 0x050000
+#if defined(QT_STATICPLUGIN)
 #include <QtPlugin>
-Q_IMPORT_PLUGIN(qcncodecs)
-Q_IMPORT_PLUGIN(qjpcodecs)
-Q_IMPORT_PLUGIN(qtwcodecs)
-Q_IMPORT_PLUGIN(qkrcodecs)
+#if defined(QT_QPA_PLATFORM_MINIMAL)
+Q_IMPORT_PLUGIN(QMinimalIntegrationPlugin);
 #endif
+#if defined(QT_QPA_PLATFORM_XCB)
+Q_IMPORT_PLUGIN(QXcbIntegrationPlugin);
+#elif defined(QT_QPA_PLATFORM_WINDOWS)
+Q_IMPORT_PLUGIN(QWindowsIntegrationPlugin);
+#elif defined(QT_QPA_PLATFORM_COCOA)
+Q_IMPORT_PLUGIN(QCocoaIntegrationPlugin);
+#endif
+#endif
+
+extern void noui_connect();
 
 // This is all you need to run all the tests
 int main(int argc, char *argv[])
diff --git a/src/qt/transactionview.cpp b/src/qt/transactionview.cpp
index 2ce6c3c3a0e1..ae8b1785481d 100644
--- a/src/qt/transactionview.cpp
+++ b/src/qt/transactionview.cpp
@@ -89,7 +89,7 @@ TransactionView::TransactionView(QWidget* parent) : QWidget(parent), model(0), t
     typeWidget->addItem(tr("Sent to"), TransactionFilterProxy::TYPE(TransactionRecord::SendToAddress) | TransactionFilterProxy::TYPE(TransactionRecord::SendToOther));
 
 /* Obsolete Obfuscation entries. Remove once the corresponding TYPES are removed:
- * 
+ *
     typeWidget->addItem(tr("Obfuscated"), TransactionFilterProxy::TYPE(TransactionRecord::Obfuscated));
     typeWidget->addItem(tr("Obfuscation Make Collateral Inputs"), TransactionFilterProxy::TYPE(TransactionRecord::ObfuscationMakeCollaterals));
     typeWidget->addItem(tr("Obfuscation Create Denominations"), TransactionFilterProxy::TYPE(TransactionRecord::ObfuscationCreateDenominations));
@@ -112,15 +112,11 @@ TransactionView::TransactionView(QWidget* parent) : QWidget(parent), model(0), t
     hlayout->addWidget(typeWidget);
 
     addressWidget = new QLineEdit(this);
-#if QT_VERSION >= 0x040700
     addressWidget->setPlaceholderText(tr("Enter address or label to search"));
-#endif
     hlayout->addWidget(addressWidget);
 
     amountWidget = new QLineEdit(this);
-#if QT_VERSION >= 0x040700
     amountWidget->setPlaceholderText(tr("Min amount"));
-#endif
 #ifdef Q_OS_MAC
     amountWidget->setFixedWidth(97);
 #else
@@ -383,7 +379,7 @@ void TransactionView::exportClicked()
     if (fExport) {
         emit message(tr("Exporting Successful"), tr("The transaction history was successfully saved to %1.").arg(filename),
                      CClientUIInterface::MSG_INFORMATION);
-    } 
+    }
     else {
         emit message(tr("Exporting Failed"), tr("There was an error trying to save the transaction history to %1.").arg(filename),
                      CClientUIInterface::MSG_ERROR);
diff --git a/src/qt/winshutdownmonitor.cpp b/src/qt/winshutdownmonitor.cpp
index a3481f17bcc5..013f937754fb 100644
--- a/src/qt/winshutdownmonitor.cpp
+++ b/src/qt/winshutdownmonitor.cpp
@@ -5,7 +5,7 @@
 
 #include "winshutdownmonitor.h"
 
-#if defined(Q_OS_WIN) && QT_VERSION >= 0x050000
+#if defined(Q_OS_WIN)
 #include "init.h"
 #include "util.h"
 
diff --git a/src/qt/winshutdownmonitor.h b/src/qt/winshutdownmonitor.h
index f24f47e80c3c..4d72d0ff784b 100644
--- a/src/qt/winshutdownmonitor.h
+++ b/src/qt/winshutdownmonitor.h
@@ -9,7 +9,6 @@
 #include <QByteArray>
 #include <QString>
 
-#if QT_VERSION >= 0x050000
 #include <windef.h> // for HWND
 
 #include <QAbstractNativeEventFilter>
@@ -24,6 +23,5 @@ class WinShutdownMonitor : public QAbstractNativeEventFilter
     static void registerShutdownBlockReason(const QString& strReason, const HWND& mainWinId);
 };
 #endif
-#endif
 
 #endif // BITCOIN_QT_WINSHUTDOWNMONITOR_H