diff --git a/validate_special_target.cmake b/validate_special_target.cmake
index 638e3d7..ae22295 100644
--- a/validate_special_target.cmake
+++ b/validate_special_target.cmake
@@ -6,7 +6,7 @@
 
 set(DESKTOP_APP_SPECIAL_TARGET "" CACHE STRING "Use special platform target, like 'macstore' for Mac App Store.")
 
-option(DESKTOP_APP_QT6 "Build with Qt 6" OFF)
+option(DESKTOP_APP_QT6 "Build with Qt 6" ${UNIX})
 
 function(report_bad_special_target)
     if (NOT DESKTOP_APP_SPECIAL_TARGET STREQUAL "")