diff --git a/src/backend/storage/aio/aio_funcs.c b/src/backend/storage/aio/aio_funcs.c
index d7977387b8f..75349ab872e 100644
--- a/src/backend/storage/aio/aio_funcs.c
+++ b/src/backend/storage/aio/aio_funcs.c
@@ -149,7 +149,7 @@ retry:
 		if (owner_pid != 0)
 			values[0] = Int32GetDatum(owner_pid);
 		else
-			nulls[0] = false;
+			nulls[0] = true;
 
 		/* column: IO's id */
 		values[1] = Int32GetDatum(ioh_id);