diff --git a/common/predictive-text/index.ts b/common/predictive-text/index.ts
index 7b67d6acb4..e739569833 100644
--- a/common/predictive-text/index.ts
+++ b/common/predictive-text/index.ts
@@ -61,6 +61,15 @@ class LMLayer {
    * Converts the INSIDE of a function into a blob URI that can
    * be passed as a valid URI for a Worker.
    * @param fn Function whose body will be referenced by a URI.
+   * 
+   * This function makes the following possible:
+   * 
+   *    let worker = new Worker(LMLayer.asBlobURI(function myWorkerCode () {
+   *      postMessage('inside Web Worker')
+   *      function onmessage(event) {
+   *        // handle message inside Web Worker.
+   *      }
+   *    }));
    */
   static asBlobURI(fn: Function): string {
     let code = LMLayer.unwrap(fn);