diff --git a/include/wx/msw/chkconf.h b/include/wx/msw/chkconf.h
index 2143e21124..049bda1362 100644
--- a/include/wx/msw/chkconf.h
+++ b/include/wx/msw/chkconf.h
@@ -224,6 +224,7 @@
 #        ifdef wxABORT_ON_CONFIG_ERROR
 #            error "wxUSE_MS_HTML_HELP requires wxUSE_DYNAMIC_LOADER."
 #        else
+#            undef wxUSE_MS_HTML_HELP
 #            define wxUSE_MS_HTML_HELP 0
 #        endif
 #    endif