diff --git a/externals/markex/abs~.c b/externals/markex/abs~.c
index 59b9666e7cf6a288f8b24532a605c755d3a02c37..2ca443e4ef5a5be50105fc9a277ceb3c0de968fb 100644
--- a/externals/markex/abs~.c
+++ b/externals/markex/abs~.c
@@ -47,6 +47,6 @@ void abs_tilde_setup(void)
     abs_class = class_new(gensym("abs~"), (t_newmethod)abs_new, 0,
     	sizeof(t_abs), 0, A_NULL);
     class_addmethod(abs_class, (t_method)nullfn, &s_signal, A_NULL);
-    class_addmethod(abs_class, (t_method)abs_dsp, gensym("dsp"), A_NULL);
+    class_addmethod(abs_class, (t_method)abs_dsp, gensym("dsp"), A_CANT, A_NULL);
 }
 
diff --git a/externals/markex/reson~.c b/externals/markex/reson~.c
index e5fead40fcd78a9b0a67356851b3027507933fcc..b5084b8d720d7a7935d3dbd68037500079306def 100644
--- a/externals/markex/reson~.c
+++ b/externals/markex/reson~.c
@@ -151,6 +151,6 @@ void reson_tilde_setup(void)
 	class_addfloat(sigreson_class, (t_method)sigreson_float);
 	class_addmethod(sigreson_class, (t_method)sigreson_ft1, gensym("ft1"), A_FLOAT, 0);
 	class_addmethod(sigreson_class, (t_method)nullfn, &s_signal, A_NULL);
-	class_addmethod(sigreson_class, (t_method)sigreson_dsp, gensym("dsp"), A_NULL);
+	class_addmethod(sigreson_class, (t_method)sigreson_dsp, gensym("dsp"), A_CANT, A_NULL);
 }