diff -ub -purN a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt	2017-06-21 03:47:15.000000000 +0200
+++ b/CMakeLists.txt	2020-01-12 02:51:41.692331365 +0100
@@ -65,10 +65,10 @@ set(CMAKE_INCLUDE_CURRENT_DIR ON) # for
 # Instruct CMake to run moc automatically when needed.
 set(CMAKE_AUTOMOC ON)
 if(NOT CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
-  set(QTAV_INSTALL_HEADERS ${CMAKE_INSTALL_PREFIX}/include)
-  set(QTAV_INSTALL_LIBS ${CMAKE_INSTALL_PREFIX}/lib)
+  set(QTAV_INSTALL_HEADERS ${QT_INSTALL_HEADERS})
+  set(QTAV_INSTALL_LIBS ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR})
   set(QTAV_INSTALL_BINS ${CMAKE_INSTALL_PREFIX}/bin)
-  set(QTAV_INSTALL_QML ${CMAKE_INSTALL_PREFIX}/qml)
+  set(QTAV_INSTALL_QML ${QT_INSTALL_QML})
 else()
   set(CMAKE_INSTALL_PREFIX ${QT_INSTALL_PREFIX} CACHE PATH "default install path" FORCE)
   set(QTAV_INSTALL_HEADERS ${QT_INSTALL_HEADERS})