diff --git a/mbf_abstract_nav/include/mbf_abstract_nav/abstract_action_base.hpp b/mbf_abstract_nav/include/mbf_abstract_nav/abstract_action_base.hpp
index 3e009dba..f5bdbb8b 100644
--- a/mbf_abstract_nav/include/mbf_abstract_nav/abstract_action_base.hpp
+++ b/mbf_abstract_nav/include/mbf_abstract_nav/abstract_action_base.hpp
@@ -143,6 +143,7 @@ class AbstractActionBase
         // if there is already a plugin running on the same slot, cancel it
         slot_it->second.execution->cancel();
 
+        // TODO + WARNING: this will block the main thread for an arbitrary time during which we won't execute callbacks
         if (slot_it->second.thread_ptr->joinable()) {
           slot_it->second.thread_ptr->join();
         }