diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 3550ef13ba..d3b00c2f9e 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -1278,6 +1278,11 @@ ParallelWorkerMain(Datum main_arg)
 												 "Parallel worker",
 												 ALLOCSET_DEFAULT_SIZES);
 
+	if (random() < INT_MAX / 64)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("fake failure to map dynamic shared memory segment")));
+
 	/*
 	 * Attach to the dynamic shared memory segment for the parallel query, and
 	 * find its table of contents.