diff --git a/gnuradio-runtime/lib/hier_block2.cc b/gnuradio-runtime/lib/hier_block2.cc
index 2211da8591..829a0d96e7 100644
--- a/gnuradio-runtime/lib/hier_block2.cc
+++ b/gnuradio-runtime/lib/hier_block2.cc
@@ -47,6 +47,7 @@ hier_block2::hier_block2(const std::string& name,
 
 hier_block2::~hier_block2()
 {
+    disconnect_all();
     gnuradio::detail::sptr_magic::cancel_initial_sptr(this);
 }