diff --git a/src/evhelper.cpp b/src/evhelper.cpp
index 8683a58..bdda230 100644
--- a/src/evhelper.cpp
+++ b/src/evhelper.cpp
@@ -98,12 +98,15 @@ struct evbase::Pvt : public epicsThreadRunable
         }
     }
 
-    virtual ~Pvt() {
+    virtual ~Pvt()
+    {
         join();
     }
 
     void join()
     {
+        if(worker.isCurrentThread())
+            log_err_printf(logerr, "evbase self-joining: %s\n", worker.getNameSelf());
         if(event_base_loopexit(base.get(), nullptr))
             log_crit_printf(logerr, "evbase error while interrupting loop for %p\n", base.get());
         worker.exitWait();