--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -1098,6 +1098,11 @@ PinBufferForBlock(Relation rel,
 
 	Assert(blockNum != P_NEW);
 
+	if (!(smgr_persistence == RELPERSISTENCE_TEMP ||
+		  smgr_persistence == RELPERSISTENCE_PERMANENT ||
+		  smgr_persistence == RELPERSISTENCE_UNLOGGED))
+		elog(WARNING, "unexpected relpersistence %d", smgr_persistence);
+
 	if (smgr_persistence == RELPERSISTENCE_TEMP)
 	{
 		io_context = IOCONTEXT_NORMAL;
====