diff --git a/Doc/library/json.rst b/Doc/library/json.rst
index 5e8c452a5ab9a1f..ddd12a002f74163 100644
--- a/Doc/library/json.rst
+++ b/Doc/library/json.rst
@@ -261,6 +261,8 @@ Basic Usage
       into JSON and then back into a dictionary, the dictionary may not equal
       the original one. That is, ``loads(dumps(x)) != x`` if x has non-string
       keys.
+      *sort_keys* sorts the keys before they are coerced to strings,
+      so numeric keys are sorted by value, not by their string representation.
 
 .. function:: load(fp, *, cls=None, object_hook=None, parse_float=None, \
                    parse_int=None, parse_constant=None, \