diff --git a/exercises/practice/parallel-letter-frequency/.approaches/config.json b/exercises/practice/parallel-letter-frequency/.approaches/config.json
index c36c194941..b2ef547535 100644
--- a/exercises/practice/parallel-letter-frequency/.approaches/config.json
+++ b/exercises/practice/parallel-letter-frequency/.approaches/config.json
@@ -12,7 +12,10 @@
       "blurb": "Use AsParallel() to parallelize counting characters.",
       "authors": [
         "erikschierboom"
-      ]
+      ],
+      "tags": {
+        "all": ["uses:Enumerable.AsParallel"]
+      }
     }
   ]
 }