diff --git a/src/Data/RandomWalkSimilarity.hs b/src/Data/RandomWalkSimilarity.hs
index 0102b9b3f..44faa2d86 100644
--- a/src/Data/RandomWalkSimilarity.hs
+++ b/src/Data/RandomWalkSimilarity.hs
@@ -45,12 +45,12 @@ rws compare as bs
           (previous, unmappedA, unmappedB) <- get
           fromMaybe (insertion previous unmappedA unmappedB kv) $ do
             foundA@(UnmappedTerm i _ a) <- nearestUnmapped unmappedA kdas kv
-            let UnmappedTerm j' _ _ = KdTree.nearest kdbs foundA
+            foundB@(UnmappedTerm j' _ _) <- nearestUnmapped unmappedB kdbs foundA
             guard (j == j')
             guard (i >= previous)
             compared <- compare a b
             pure $! do
-              put (i, List.delete foundA unmappedA, List.delete kv unmappedB)
+              put (i, List.delete foundA unmappedA, List.delete foundB unmappedB)
               pure (i, compared)
         nearestUnmapped unmapped tree key = let UnmappedTerm i _ _ = KdTree.nearest tree key in
           find ((== i) . termIndex) unmapped