diff --git a/gnuradio-runtime/lib/hier_block2_detail.h b/gnuradio-runtime/lib/hier_block2_detail.h
index 20f77b121a..8254720fc2 100644
--- a/gnuradio-runtime/lib/hier_block2_detail.h
+++ b/gnuradio-runtime/lib/hier_block2_detail.h
@@ -83,6 +83,7 @@ class GR_RUNTIME_API hier_block2_detail
     void set_parent(hier_block2* parent);
     void reset_parent(bool force = false);
     void reset_hier_blocks_parent();
+    void recursive_disconnect_all(hier_block2* caller);
 };
 
 } /* namespace gr */