diff --git a/src/backend/storage/aio/aio_init.c b/src/backend/storage/aio/aio_init.c
index 885c3940c66..54ab84dd6f0 100644
--- a/src/backend/storage/aio/aio_init.c
+++ b/src/backend/storage/aio/aio_init.c
@@ -30,12 +30,8 @@
 static Size
 AioCtlShmemSize(void)
 {
-	Size		sz;
-
 	/* pgaio_ctl itself */
-	sz = offsetof(PgAioCtl, io_handles);
-
-	return sz;
+	return sizeof(PgAioCtl);
 }
 
 static uint32