diff --git a/docs/api.rst b/docs/api.rst
index 9d6cb81..323d5e6 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -144,4 +144,4 @@ Schema-Related
 
      Represents a value that will be dropped from the schema if it is missing
      during *deserialization*.  Passed as a value to the `missing` keyword
-     argument.
+     argument of :class:`SchemaNode`.