diff --git a/docs/ref/models/constraints.txt b/docs/ref/models/constraints.txt
index 77b9ea9c3c..6d24f43f67 100644
--- a/docs/ref/models/constraints.txt
+++ b/docs/ref/models/constraints.txt
@@ -56,7 +56,7 @@ The name of the constraint.
 ``UniqueConstraint``
 ====================
 
-.. class:: UniqueConstraint(*, fields, name)
+.. class:: UniqueConstraint(*, fields, name, condition=None)
 
     Creates a unique constraint in the database.