diff --git a/src/lib/data/html/marker.js b/src/lib/data/html/marker.js
index a92315a23..24fced20e 100644
--- a/src/lib/data/html/marker.js
+++ b/src/lib/data/html/marker.js
@@ -101,7 +101,7 @@
     }
 
     function generateKeys(markerContainer) {
-        let lettersString = "ASDTJHNELFI";
+        let lettersString = "ARSTDHNELFI";
         let letters = lettersString.split("");
         let nodeNum = markerContainer.children.length;
         let keyLen = nodeNum == 1 ? 1 : Math.ceil(Math.log(nodeNum)/Math.log(letters.length));