diff --git a/docs/source/api_reference/param_est.rst b/docs/source/api_reference/param_est.rst
index 9bb1a2cdd07..be536d40995 100644
--- a/docs/source/api_reference/param_est.rst
+++ b/docs/source/api_reference/param_est.rst
@@ -41,6 +41,7 @@ Composition
     :template: class.rst
 
     PluginParamsForecaster
+    PluginParamsTransformer
 
 Naive
 ~~~~~