diff --git a/documentation/reference-library-index.md b/documentation/reference-library-index.md
index 9a04a09f8..aba3a2c40 100644
--- a/documentation/reference-library-index.md
+++ b/documentation/reference-library-index.md
@@ -164,6 +164,8 @@ and a change here can break other maps.
   `import … from '@map/utils/embedBase.js'`
 - **geoUtils** — geoUtils.js — Geographic / GeoJSON Utility Functions  
   `import … from '@map/utils/geoUtils.js'`
+- **viewportScrim** — viewportScrim.js — make a position:fixed full-screen SCRIM actually cover the VIEWPORT,  
+  `import … from '@map/utils/viewportScrim.js'`
 
 ### Stores (Pinia — shared state)