--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -2303,7 +2303,8 @@ ReorderBufferRestoreChange(ReorderBuffer
 		case REORDER_BUFFER_CHANGE_DELETE:
 			if (change->data.tp.oldtuple)
 			{
-				Size		tuplelen = ((HeapTuple) data)->t_len;
+				Size		tuplelen;
+				memcpy(&tuplelen, &((HeapTuple) data)->t_len, sizeof(uint32));
 
 				change->data.tp.oldtuple =
 					ReorderBufferGetTupleBuf(rb, tuplelen - offsetof(HeapTupleHeaderData, t_bits));
@@ -2324,7 +2325,8 @@ ReorderBufferRestoreChange(ReorderBuffer
 
 			if (change->data.tp.newtuple)
 			{
-				Size		tuplelen = ((HeapTuple) data)->t_len;
+				Size		tuplelen;
+				memcpy(&tuplelen, &((HeapTuple) data)->t_len, sizeof(uint32));
 
 				change->data.tp.newtuple =
 					ReorderBufferGetTupleBuf(rb, tuplelen - offsetof(HeapTupleHeaderData, t_bits));