diff --git a/include/wx/msw/chkconf.h b/include/wx/msw/chkconf.h
index 3d421e5502..53059846ab 100644
--- a/include/wx/msw/chkconf.h
+++ b/include/wx/msw/chkconf.h
@@ -236,6 +236,7 @@
 #        ifdef wxABORT_ON_CONFIG_ERROR
 #            error "wxUSE_DIALUP_MANAGER requires wxUSE_DYNAMIC_LOADER."
 #        else
+#            undef wxUSE_DIALUP_MANAGER
 #            define wxUSE_DIALUP_MANAGER 0
 #        endif
 #    endif