diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index e60433ba0b..0a6314a642 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -4131,7 +4131,7 @@ CleanupBackupHistory(void)
 /*
  * Attempt to read an XLOG record.
  *
- * If RecPtr is not NULL, try to read a record at that position.  Otherwise
+ * If RecPtr is valid, try to read a record at that position.  Otherwise
  * try to read a record just after the last one previously read.
  *
  * If no valid record is available, returns NULL, or fails if emode is PANIC.