diff --git a/docs/ref/models/expressions.txt b/docs/ref/models/expressions.txt
index fe7aecfbc01..ccd75d62a96 100644
--- a/docs/ref/models/expressions.txt
+++ b/docs/ref/models/expressions.txt
@@ -944,6 +944,9 @@ calling the appropriate methods on the wrapped expression.
         ``summarize`` is a boolean that, when ``True``, signals that the
         query being computed is a terminal aggregate query.
 
+        ``for_save`` is a boolean that, when ``True``, signals that the query
+        being executed is performing a create or update.
+
     .. method:: get_source_expressions()
 
         Returns an ordered list of inner expressions. For example::