diff --git a/documentation/wntr-api.rst b/documentation/wntr-api.rst
index b023e5b2e..b5ffe3bb0 100644
--- a/documentation/wntr-api.rst
+++ b/documentation/wntr-api.rst
@@ -27,6 +27,8 @@ API documentation
         wntr.utils
 
 .. toctree::
+    :caption: Appendices
+    :hidden:
 
     acronyms
     reference