diff --git a/kde-modules/KDEInstallDirs.cmake b/kde-modules/KDEInstallDirs.cmake
--- a/kde-modules/KDEInstallDirs.cmake
+++ b/kde-modules/KDEInstallDirs.cmake
@@ -716,3 +716,7 @@
 if(KDE_INSTALL_PREFIX_SCRIPT)
     install(FILES ${CMAKE_CURRENT_BINARY_DIR}/prefix.sh DESTINATION ${CMAKE_INSTALL_PREFIX} PERMISSIONS OWNER_EXECUTE OWNER_WRITE OWNER_READ)
 endif()
+
+if(NOT KDE_INSTALL_USE_QT_SYS_PATHS)
+    message(NOTICE "Installing in ${CMAKE_INSTALL_PREFIX}, remember set the environment. See ${CMAKE_CURRENT_BINARY_DIR}/prefix.sh")
+endif()