diff --git src/main/scala/io/radanalytics/equoid/topk.scala src/main/scala/io/radanalytics/equoid/topk.scala
index 25801e7..639071e 100644
--- src/main/scala/io/radanalytics/equoid/topk.scala
+++ src/main/scala/io/radanalytics/equoid/topk.scala
@@ -23,10 +23,13 @@ class TopK[V] (
     val ucms: CountMinSketch = ecms.mergeInPlace(this.cms)
     ucms.add(v, 1)
     val vf = ucms.estimateCount(v).toInt
-    val (utopk, ufmin) = if (topk.size < k) {
-      (topk + (v -> vf), math.min(vf, fmin))
+    val (utopk, ufmin) = if (topk.size < k || topk.contains(v)) {
+      (topk + (v -> vf), vf)
     } else if (vf <= fmin) (topk, fmin) else {
       val del = topk.minBy { case (_, f) => f }