diff --git a/source/sdk/flutter/realm-database/define-realm-object-schema.txt b/source/sdk/flutter/realm-database/define-realm-object-schema.txt
index 6addc569a4..22e03b017e 100644
--- a/source/sdk/flutter/realm-database/define-realm-object-schema.txt
+++ b/source/sdk/flutter/realm-database/define-realm-object-schema.txt
@@ -280,7 +280,16 @@ Indexed
 
 Add the `Indexed <https://pub.dev/documentation/realm_common/latest/realm_common/Indexed-class.html>`__ annotation
 to create an index on the field. Indexes slightly slow down insertion, but can greatly
-speed up queries.
+speed up queries. Indexes can be nullable.
+
+The following data types can be indexed:
+
+- ``bool``
+- ``int``
+- ``String``
+- ``ObjectId``
+- ``Uuid``
+- ``DateTime``
 
 .. literalinclude:: /examples/generated/flutter/schemas.snippet.property-annotations.dart
    :language: dart