diff --git a/src/scala/com/twitter/simclusters_v2/scalding/KnownForSources.scala b/src/scala/com/twitter/simclusters_v2/scalding/KnownForSources.scala
index 217f521ac..5f96df6a5 100644
--- a/src/scala/com/twitter/simclusters_v2/scalding/KnownForSources.scala
+++ b/src/scala/com/twitter/simclusters_v2/scalding/KnownForSources.scala
@@ -102,23 +102,23 @@ object KnownForSources {
     TypedPipe
       .from(TextLine(textFile))
       .flatMap { str =>
-        if (!str.startsWith("#")) {
-          try {
+        str match {
+          case s"#$_" => None
+          case _ => try {
             val tokens = str.trim.split("\\s+")
-            val res = Array.newBuilder[(Int, Float)]
             val userId = tokens(0).toLong
-            for (i <- 1 until tokens.length) {
+            (1 until tokens.length).foldRight(Array.newBuilder[(Int, Float)])((i, r) => {
               val Array(cIdStr, scoreStr) = tokens(i).split(":")
               val clusterId = cIdStr.toInt
               val score = scoreStr.toFloat
               val newEntry = (clusterId, score)
-              res += newEntry
+              r += newEntry
+            }).result() match {
+              case (res) if res.nonEmpty => Some((userId, res.result()))
+                _ => None
             }
-            val result = res.result
-            if (result.nonEmpty) {
-              Some((userId, res.result()))
-            } else None
-          } catch {
+          }
+          catch {
             case ex: Throwable =>
               log.warning(
                 s"Error while loading knownFor from $textFile for line <$str>: " +
@@ -126,7 +126,7 @@ object KnownForSources {
               )
               None
           }
-        } else None
+        }
       }
   }