diff --git a/README.md b/README.md
index bb8eb1b..2b09369 100644
--- a/README.md
+++ b/README.md
@@ -122,14 +122,14 @@ You can configure the client (the JS part) via `data-` attributes:
 
     Make sure to escape the attribute value.
 
-*   data-prefix
+*   data-isso
 
     Isso usually detects the REST API automatically, but when you serve the JS
-    script on a different location, this may fail. Use `data-prefix` to
+    script on a different location, this may fail. Use `data-isso` to
     override the API location:
 
      ```html
-     <script data-prefix="/isso" src="/path/to/embed.min.js"></script>
+     <script data-isso="/isso" src="/path/to/embed.min.js"></script>
      ```
 
 ### Webserver configuration
diff --git a/isso/js/app/api.js b/isso/js/app/api.js
index 395b664..6daf5c4 100644
--- a/isso/js/app/api.js
+++ b/isso/js/app/api.js
@@ -30,19 +30,18 @@ define(["q"], function(Q) {
      *
      *      .. code-block:: html
      *
-     *          <script data-prefix="/path" src="/.../embed.min.js"></script>
+     *          <script data-isso="http://example.tld/path/" src="/.../embed.min.js"></script>
      *
      *   2. use require.js (during development). When using require.js, we
      *      assume that the path to the scripts ends with `/js/`.
-     *
      */
 
     var script, endpoint,
         js = document.getElementsByTagName("script");
 
     for (var i = 0; i < js.length; i++) {
-        if (js[i].dataset.issoPrefix !== undefined) {
-            endpoint = js[i].dataset.issoPrefix;
+        if (js[i].dataset.isso !== undefined) {
+            endpoint = js[i].dataset.isso;
         } else if (js[i].src.match("require\\.js$")) {
             endpoint = js[i].dataset.main.replace(/\/js\/(embed|count)$/, "");
         }