diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 3550ef13ba..5f690393fc 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -1305,7 +1305,7 @@ ParallelWorkerMain(Datum main_arg)
 	/* Arrange to signal the leader if we exit. */
 	ParallelLeaderPid = fps->parallel_leader_pid;
 	ParallelLeaderBackendId = fps->parallel_leader_backend_id;
-	on_shmem_exit(ParallelWorkerShutdown, (Datum) 0);
+	before_shmem_exit(ParallelWorkerShutdown, PointerGetDatum(seg));
 
 	/*
 	 * Now we can find and attach to the error queue provided for us.  That's
@@ -1507,6 +1507,16 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
  * This guards against the case where we exit uncleanly without sending an
  * ErrorResponse to the leader, for example because some code calls proc_exit
  * directly.
+ *
+ * Also explicitly detach from dsm segment so that subsystems using
+ * on_dsm_detach() have a chance to send stats before the stats subsystem is
+ * shut down as as part of a before_shmem_exit() hook.
+ *
+ * One might think this could instead be solved by carefully ordering the
+ * attaching to dsm segments, so that the pgstats segments get detached from
+ * later than the parallel query one. That turns out to not work because the
+ * stats hash might need to grow which can cause new segments to be allocated,
+ * which then will be detached from earlier.
  */
 static void
 ParallelWorkerShutdown(int code, Datum arg)
@@ -1514,6 +1524,8 @@ ParallelWorkerShutdown(int code, Datum arg)
 	SendProcSignal(ParallelLeaderPid,
 				   PROCSIG_PARALLEL_MESSAGE,
 				   ParallelLeaderBackendId);
+
+	dsm_detach((dsm_segment *) DatumGetPointer(arg));
 }
 
 /*