diff --git a/static/js/ArrayExtensions.js b/static/js/ArrayExtensions.js
index 3a2725d1..0a67f5d0 100644
--- a/static/js/ArrayExtensions.js
+++ b/static/js/ArrayExtensions.js
@@ -6,4 +6,13 @@ if (!Array.prototype.findAsync) {
       }
     }
   }
+  if (!Array.prototype.findAllIndexes) {
+    Array.prototype.findAllIndexes = function (Callback) {
+      this.reduce(function(a, e, i) {
+        if (Callback(e))
+          a.push(i)
+        return a
+    }, [])
+    }
+  }
 }
\ No newline at end of file