--- lib/cmake/FindQt5Transitional.cmake
+++ lib/cmake/FindQt5Transitional.cmake
@@ -1,5 +1,8 @@
+option(WITH_Qt5 ON)
 
-find_package(Qt5Core QUIET)
+if (WITH_Qt5)
+  find_package(Qt5Core QUIET)
+endif()
 
 if (Qt5Core_FOUND)
   if (NOT Qt5Transitional_FIND_COMPONENTS)