diff --git a/Day1B.hs b/Day1B.hs
index 5c096ef..04db47a 100644
--- a/Day1B.hs
+++ b/Day1B.hs
@@ -5,9 +5,8 @@ import qualified Data.IntSet as S
 
 handle :: Int -> S.IntSet -> [Int] -> Int
 handle freq history (nextDelta:xs)
-  | (S.size s) == (S.size history) = freq  -- When the frequency is in the history set, return it
-  | otherwise                      = handle (freq + nextDelta) (S.insert freq history) xs  -- Recurse otherwise
-  where s = S.insert freq history
+  | S.member freq history = freq  -- When the frequency is in the history set, return it
+  | otherwise             = handle (freq + nextDelta) (S.insert freq history) xs  -- Recurse otherwise
 handle _ _ _ = error "xs should not be empty :("
 
 main :: IO ()