diff --git a/cmake/QtProcessConfigureArgs.cmake b/cmake/QtProcessConfigureArgs.cmake
index 24e8c64dc6b..c8a18fd6549 100644
--- a/cmake/QtProcessConfigureArgs.cmake
+++ b/cmake/QtProcessConfigureArgs.cmake
@@ -391,7 +391,7 @@ function(qt_commandline_addString arg val nextok)
     qtConfValidateValue("${arg}" "${val}" success)
     if(success)
         if(DEFINED command_line_option_${arg}_variable)
-            set(opt ${command_line_option_${arg}_variable)
+            set(arg ${command_line_option_${arg}_variable})
         endif()
         set_property(GLOBAL APPEND PROPERTY "INPUT_${arg}" "${val}")
         set_property(GLOBAL APPEND PROPERTY CONFIG_INPUTS ${arg})