diff --git a/CMakeLists.txt b/CMakeLists.txt
index a55999935daa27ffc48492043cac819e842b69c6..def276b350f26ff546a2d1f283389a14fa267492 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,7 +16,7 @@ endif()
 OPTION(PEDANTIC "Enable all compiler warnings" OFF)
 
 # Options (cmake -LH)
-OPTION(WITH_QT5 "Qt5 support" OFF)
+OPTION(WITH_QT5 "Use Qt 5 (disable to use Qt 4 instead)" ON)
 OPTION(WITH_TESTS "Run test cases from command line" ${COPYQ_DEBUG})
 OPTION(WITH_PLUGINS "Compile plugins" ON)
 # Linux-specific options
@@ -32,26 +32,23 @@ endif()
 
 set(CMAKE_AUTOMOC ON)
 
-# If Qt4 unavailable use Qt5.
-if (NOT WITH_QT5)
+if (WITH_QT5)
+    cmake_minimum_required(VERSION 2.8.8)
+    find_package(Qt5Widgets)
+    if (NOT Qt5Widgets_FOUND)
+        message(FATAL_ERROR "Qt 5 is unavailable. To compile with Qt 4 use -DWITH_QT5=OFF.")
+    endif()
+    message(STATUS "Building with Qt 5.")
+else()
     find_package(Qt4)
     if (NOT QT4_FOUND)
         # Try different executable name.
         set(QT_QMAKE_EXECUTABLE "qmake-qt4")
         find_package(Qt4)
         if (NOT QT4_FOUND)
-            message(FATAL_ERROR
-                    "Qt 4 is unavailable. To compile with Qt 5 use -DWITH_QT5=TRUE.\n"
-                    "Note: Qt version 5.0.2 and earlier can be unstable on some systems.")
+            message(FATAL_ERROR "Qt 4 is unavailable. To compile with Qt 5 use -DWITH_QT5=ON.")
         endif()
     endif()
-endif()
-
-if (WITH_QT5)
-    cmake_minimum_required(VERSION 2.8.8)
-    find_package(Qt5Widgets REQUIRED)
-    message(STATUS "Building with Qt 5.")
-else()
     message(STATUS "Building with Qt 4.")
 endif()
 
diff --git a/utils/appveyor/before_build.bat b/utils/appveyor/before_build.bat
index e0e06438905197c0fe3bbd51a4c5992e37192a9f..baa0daf687b41e6de48b2346ee3e16eb60ee9537 100644
--- a/utils/appveyor/before_build.bat
+++ b/utils/appveyor/before_build.bat
@@ -1 +1 @@
-cmake -H. -Bbuild -DCMAKE_BUILD_TYPE=Release -G "%CMAKE_GENERATOR%" -DWITH_QT5=ON -DWITH_TESTS=ON
+cmake -H. -Bbuild -DCMAKE_BUILD_TYPE=Release -G "%CMAKE_GENERATOR%" -DWITH_TESTS=ON
diff --git a/utils/gitlab/build-script.sh b/utils/gitlab/build-script.sh
index b1ec27a584acf0163756e49f8096830d4ce1b6ce..d5a5fb253f8f064d7689f584e964530f77357f8a 100755
--- a/utils/gitlab/build-script.sh
+++ b/utils/gitlab/build-script.sh
@@ -7,7 +7,6 @@ INSTALL_PREFIX=$(readlink -f "$INSTALL_PREFIX")
 
 cmake_args=(
     -DWITH_TESTS=TRUE
-    -DWITH_QT5=TRUE
     -DCMAKE_INSTALL_PREFIX="$INSTALL_PREFIX"
     ..
 )
diff --git a/utils/travis/script-linux.sh b/utils/travis/script-linux.sh
index 115f728430bc78040940974a7a806e25f2fb199c..2064b432de4fd6c4ef316b9d5aed2619b20f868b 100755
--- a/utils/travis/script-linux.sh
+++ b/utils/travis/script-linux.sh
@@ -10,7 +10,13 @@ cd build
 # Configure.
 if [ "$CC" == "gcc" ]; then
     # GCC build generates coverage.
-    cmake -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_COMPILER=$COMPILER -DCMAKE_CXX_FLAGS=--coverage -DCMAKE_C_FLAGS=--coverage ..
+    cmake \
+        -DCMAKE_BUILD_TYPE=Debug \
+        -DCMAKE_CXX_COMPILER=$COMPILER \
+        -DCMAKE_CXX_FLAGS=--coverage \
+        -DCMAKE_C_FLAGS=--coverage \
+        -DWITH_QT5=OFF \
+        ..
 else
     qmake CONFIG+=debug QMAKE_CXX=$COMPILER QMAKE_CXXFLAGS="-std=c++11" ..
 fi