diff --git a/CMakeLists.txt b/CMakeLists.txt
index 96a4dec..10725fc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,96 +1,96 @@
 project(kjumpingcube)
 
-cmake_minimum_required (VERSION 2.8.12 FATAL_ERROR)
+cmake_minimum_required (VERSION 3.5 FATAL_ERROR)
 set (QT_MIN_VERSION "5.7.0")
 set (KF5_MIN_VERSION "5.30.0")
 
 find_package(ECM ${KF5_MIN_VERSION} REQUIRED CONFIG)
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${ECM_MODULE_PATH} ${ECM_KDE_MODULE_DIR})
 
 find_package(Qt5 ${QT_MIN_VERSION} REQUIRED NO_MODULE COMPONENTS Widgets Svg)
 find_package(KF5 ${KF5_MIN_VERSION} REQUIRED COMPONENTS
     CoreAddons
     Config
     ConfigWidgets
     Crash
     DBusAddons
     DocTools
     KIO
     I18n
     XmlGui
     WidgetsAddons
 )
 
 find_package(KF5KDEGames 4.9.0 REQUIRED)
 
 include(FeatureSummary)
 include(ECMAddAppIcon)
 include(ECMInstallIcons)
 include(KDEInstallDirs)
 include(KDECompilerSettings NO_POLICY_SCOPE)
 include(KDECMakeSettings)
 include(ECMQtDeclareLoggingCategory)
 
 add_definitions(-DQT_USE_FAST_CONCATENATION -DQT_USE_FAST_OPERATOR_PLUS)
 add_definitions(-DQT_NO_URL_CAST_FROM_STRING)
 
 add_subdirectory(pics)
 add_subdirectory(doc)
 
 ########### next target ###############
 
 set(kjumpingcube_SRCS 
    kjumpingcube.cpp 
    kcubeboxwidget.cpp 
    main.cpp 
    kcubewidget.cpp 
    game.cpp
    ai_main.cpp
    ai_kepler.cpp
    ai_newton.cpp
    ai_box.cpp
 )
 
 ecm_qt_declare_logging_category(kjumpingcube_SRCS HEADER kjumpingcube_debug.h IDENTIFIER KJUMPINGCUBE_LOG CATEGORY_NAME org.kde.kjumpingcube)
 
 qt5_add_resources(kjumpingcube_SRCS kjumpingcube.qrc)
 ki18n_wrap_ui(kjumpingcube_SRCS settings.ui)
 
 kconfig_add_kcfg_files(kjumpingcube_SRCS prefs.kcfgc)
 
 file(GLOB ICONS_SRCS "${CMAKE_CURRENT_SOURCE_DIR}/*-apps-kjumpingcube.png")
 ecm_add_app_icon(kjumpingcube_SRCS ICONS ${ICONS_SRCS})
 add_executable(kjumpingcube ${kjumpingcube_SRCS})
 
 target_link_libraries(kjumpingcube
     KF5KDEGames
     KF5::CoreAddons
     KF5::Crash
     KF5::DBusAddons
     KF5::KIOWidgets
     KF5::XmlGui
     Qt5::Svg
 )
 
 install(TARGETS kjumpingcube  ${KDE_INSTALL_TARGETS_DEFAULT_ARGS})
 
 
 ########### install files ###############
 
 install(PROGRAMS org.kde.kjumpingcube.desktop  DESTINATION  ${KDE_INSTALL_APPDIR})
 install(FILES org.kde.kjumpingcube.appdata.xml DESTINATION  ${KDE_INSTALL_METAINFODIR})
 install(FILES kjumpingcube.kcfg  DESTINATION  ${KDE_INSTALL_KCFGDIR})
 
 ecm_install_icons(ICONS
     128-apps-kjumpingcube.png
     16-apps-kjumpingcube.png
     22-apps-kjumpingcube.png
     32-apps-kjumpingcube.png
     48-apps-kjumpingcube.png
     64-apps-kjumpingcube.png
     DESTINATION ${KDE_INSTALL_ICONDIR} THEME hicolor
 )
 
 install( FILES kjumpingcube.categories DESTINATION ${KDE_INSTALL_CONFDIR} )
 
 feature_summary(WHAT ALL INCLUDE_QUIET_PACKAGES FATAL_ON_MISSING_REQUIRED_PACKAGES)