diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -35,10 +35,9 @@
 function(qtc_option name doc def_val)
   if(DEFINED "${name}")
     set("${name}_DEFINED" On PARENT_SCOPE)
-    option("${name}" "${doc}" On)
   else()
     set("${name}_DEFINED" Off PARENT_SCOPE)
-    option("${name}" "${doc}" "${def_val}")
+    set("${name}" "${def_val}" ${doc} PARENT_SCOPE)
   endif()
 endfunction()
 function(qtc_variable name doc def_val)