diff --git a/CMakeLists.txt b/CMakeLists.txt
index 87664ac..0e73db2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,7 +2,6 @@ cmake_minimum_required( VERSION 2.8 )
 
 project(qtermwidget)
 
-option(USE_QT5 "Build using Qt5. Default OFF." OFF)
 option(BUILD_TEST "Build test application. Default OFF." OFF)
 
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake")
@@ -25,13 +24,8 @@ include_directories(
 add_definitions(-Wall)
 
 
-if(USE_QT5)
-    set(QTERMWIDGET_LIBRARY_NAME qtermwidget5)
-    include(qtermwidget5_use)
-else()
-    include(qtermwidget4_use)
-    set(QTERMWIDGET_LIBRARY_NAME qtermwidget4)
-endif()
+set(QTERMWIDGET_LIBRARY_NAME qtermwidget5)
+include(qtermwidget5_use)
 
 
 # main library
@@ -110,17 +104,9 @@ if(HAVE_UPDWTMPX)
     add_definitions(-DHAVE_UPDWTMPX)
 endif()
 
-
-if(USE_QT5)
-    qt5_wrap_cpp(MOCS ${HDRS})
-    qt5_wrap_ui(UI_SRCS ${UI})
-    set(PKG_CONFIG_REQ "Qt5Core, Qt5Xml, Qt5Widgets")
-else()
-    qt4_wrap_cpp(MOCS ${HDRS})
-    qt4_wrap_ui(UI_SRCS ${UI})
-    set(PKG_CONFIG_REQ "QtCore, QtXml")
-endif()
-
+qt5_wrap_cpp(MOCS ${HDRS})
+qt5_wrap_ui(UI_SRCS ${UI})
+set(PKG_CONFIG_REQ "Qt5Core, Qt5Xml, Qt5Widgets")
 
 add_library(${QTERMWIDGET_LIBRARY_NAME} SHARED ${SRCS} ${MOCS} ${UI_SRCS})
 target_link_libraries(${QTERMWIDGET_LIBRARY_NAME} ${QTERMWIDGET_QT_LIBRARIES})
diff --git a/INSTALL b/INSTALL
index e26c91a..1053de7 100644
--- a/INSTALL
+++ b/INSTALL
@@ -1,6 +1,6 @@
 Requirements:
 
-    Qt4 or Qt5
+    Qt >= 5.4
     cmake
 
 Supported (tested) platforms:
@@ -15,8 +15,7 @@ Build:
     http://www.cmake.org/Wiki/CMake_FAQ#Out-of-source_build_trees
 
     1) mkdir -p build && cd build
-    2a) cmake path/to/source -DUSE_QT5=true  # Qt 5
-    2b) cmake path/to/source  # Qt 4 only
+    2) cmake path/to/source
     3) make
     4) optional: make install
 
diff --git a/cmake/qtermwidget4-config.cmake.in b/cmake/qtermwidget4-config.cmake.in
deleted file mode 100644
index 7f3a10f..0000000
--- a/cmake/qtermwidget4-config.cmake.in
+++ /dev/null
@@ -1,47 +0,0 @@
-# - Find the QTermWidget include and library dirs and define a some macros
-#
-# The module defines the following variables
-#  QTERMWIDGET_FOUND         - Set to TRUE if all of the above has been found
-#
-#  QTERMWIDGET_INCLUDE_DIR   - The QTermWidget include directory
-#
-#  QTERMWIDGET_INCLUDE_DIRS  - The QTermWidget include directory
-#
-#  QTERMWIDGET_LIBRARIES     - The libraries needed to use QTermWidget
-#
-#  QTERMWIDGET_USE_FILE      - The variable QTERMWIDGET_USE_FILE is set which is the path
-#                              to a CMake file that can be included to compile qtermwidget
-#                              applications and libraries. It sets up the compilation
-#                              environment for include directories and populates a
-#                              QTERMWIDGET_LIBRARIES variable.
-#
-# QTERMWIDGET_QT_LIBRARIES   - The Qt libraries needed by QTermWidget
-#
-# Typical usage:
-#    option(USE_QT5 "Build using Qt5. Default off" OFF)
-#    if (USE_QT5)
-#        find_package(QTERMWIDGET4)
-#    else()
-#        find_package(QTERMWIDGET5)
-#    endif()
-#
-#    include(${QTERMWIDGET_USE_FILE})
-#    add_executable(foo main.cpp)
-#    target_link_libraries(foo ${QTERMWIDGET_QT_LIBRARIES} ${QTERMWIDGET_LIBRARIES})
-
-set(QTERMWIDGET_INCLUDE_DIR   @QTERMWIDGET_INCLUDE_DIR@)
-set(QTERMWIDGET_LIBRARY       @QTERMWIDGET_LIBRARY_NAME@)
-
-set(QTERMWIDGET_LIBRARIES     ${QTERMWIDGET_LIBRARY})
-set(QTERMWIDGET_INCLUDE_DIRS  "${QTERMWIDGET_INCLUDE_DIR}")
-
-set(QTERMWIDGET_USE_FILE      "${CMAKE_CURRENT_LIST_DIR}/qtermwidget4_use.cmake")
-set(QTERMWIDGET_FOUND 1)
-
-set(QTERMWIDGET_VERSION_MAJOR @QTERMWIDGET_VERSION_MAJOR@)
-set(QTERMWIDGET_VERSION_MINOR @QTERMWIDGET_VERSION_MINOR@)
-set(QTERMWIDGET_VERSION_PATCH @QTERMWIDGET_VERSION_PATCH@)
-set(QTERMWIDGET_VERSION @QTERMWIDGET_VERSION@)
-
-mark_as_advanced(QTERMWIDGET_LIBRARY QTERMWIDGET_INCLUDE_DIR)
-
diff --git a/cmake/qtermwidget5-config.cmake.in b/cmake/qtermwidget5-config.cmake.in
index 5f8edb9..83295e4 100644
--- a/cmake/qtermwidget5-config.cmake.in
+++ b/cmake/qtermwidget5-config.cmake.in
@@ -18,12 +18,7 @@
 # QTERMWIDGET_QT_LIBRARIES   - The Qt libraries needed by QTermWidget
 #
 # Typical usage:
-#    option(USE_QT5 "Build using Qt5. Default off" OFF)
-#    if (USE_QT5)
-#        find_package(QTERMWIDGET4)
-#    else()
-#        find_package(QTERMWIDGET5)
-#    endif()
+#    find_package(QTERMWIDGET5)
 #
 #    include(${QTERMWIDGET_USE_FILE})
 #    add_executable(foo main.cpp)
@@ -44,4 +39,3 @@ set(QTERMWIDGET_VERSION_PATCH @QTERMWIDGET_VERSION_PATCH@)
 set(QTERMWIDGET_VERSION @QTERMWIDGET_VERSION@)
 
 mark_as_advanced(QTERMWIDGET_LIBRARY QTERMWIDGET_INCLUDE_DIR)
-
diff --git a/lib/Session.cpp b/lib/Session.cpp
index 7d2a773..42d93c3 100644
--- a/lib/Session.cpp
+++ b/lib/Session.cpp
@@ -121,42 +121,11 @@ Session::Session(QObject* parent) :
 
 WId Session::windowId() const
 {
-    // Returns a window ID for this session which is used
-    // to set the WINDOWID environment variable in the shell
-    // process.
-    //
-    // Sessions can have multiple views or no views, which means
-    // that a single ID is not always going to be accurate.
-    //
-    // If there are no views, the window ID is just 0.  If
-    // there are multiple views, then the window ID for the
-    // top-level window which contains the first view is
-    // returned
-	//
-	// On Qt5, requesting window IDs breaks QQuickWidget and the likes,
-	// for example, see the following bug reports:
-	//
-	// https://bugreports.qt-project.org/browse/QTBUG-41779
-	// https://bugreports.qt-project.org/browse/QTBUG-40765
-	// https://bugreports.qt-project.org/browse/QTBUG-41942
-
-#if QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)
-	return 0;
-#else
-    if ( _views.count() == 0 ) {
-        return 0;
-    } else {
-        QWidget * window = _views.first();
-
-        Q_ASSERT( window );
-
-        while ( window->parentWidget() != 0 ) {
-            window = window->parentWidget();
-        }
-
-        return window->winId();
-    }
-#endif
+    // On Qt5, requesting window IDs breaks QQuickWidget and the likes,
+    // for example, see the following bug reports:
+    // https://bugreports.qt.io/browse/QTBUG-40765
+    // https://codereview.qt-project.org/#/c/94880/
+    return 0;
 }
 
 void Session::setDarkBackground(bool darkBackground)
diff --git a/lib/TerminalDisplay.cpp b/lib/TerminalDisplay.cpp
index 18b0f47..ad8b94d 100644
--- a/lib/TerminalDisplay.cpp
+++ b/lib/TerminalDisplay.cpp
@@ -726,15 +726,11 @@ void TerminalDisplay::drawCharacters(QPainter& painter,
         // the application's default layout direction to be used instead of
         // the widget-specific layout direction, which should always be
         // Qt::LeftToRight for this widget
-    // This was discussed in: http://lists.kde.org/?t=120552223600002&r=1&w=2
+        // This was discussed in: http://lists.kde.org/?t=120552223600002&r=1&w=2
         if (_bidiEnabled)
             painter.drawText(rect,0,text);
         else
-#if QT_VERSION >= 0x040800
             painter.drawText(rect, Qt::AlignBottom, LTR_OVERRIDE_CHAR + text);
-#else
-            painter.drawText(rect, 0, LTR_OVERRIDE_CHAR + text);
-#endif
     }
 }