diff --git a/2015/day07/day07.hs b/2015/day07/day07.hs
index ba042d4..8dcd381 100644
--- a/2015/day07/day07.hs
+++ b/2015/day07/day07.hs
@@ -45,4 +45,4 @@ part2 :: [(String, (Op, String, String))] -> Int -> Int
 part2 wires part1Answer = fst $ eval'' wires [("b", part1Answer)] "a"
 
 main :: IO ()
-main = aocMain' parseFile (passthrough . part1) part2
\ No newline at end of file
+main = aocMain' parseFile (dup . part1) part2
\ No newline at end of file
diff --git a/aoc.hs b/aoc.hs
index 8bc603e..b030b74 100644
--- a/aoc.hs
+++ b/aoc.hs
@@ -9,10 +9,10 @@ aocMain' parseFile part1 part2 = do
     let part2Answer = part2 input data'
     putStrLn $ "Part 2: " ++ show part2Answer
 
-passthrough :: a -> (a, a)
-passthrough a = (a, a)
+dup :: a -> (a, a)
+dup a = (a, a)
 
-aocMain :: Show p => ([String] -> p) -> (p -> Int) -> (p -> Int) -> IO ()
+aocMain :: (Show p, Show a) => ([String] -> p) -> (p -> a) -> (p -> a) -> IO ()
 aocMain parseFile part1 part2 = aocMain' parseFile ((,()) . part1) (const' part2)
 
 const' :: (a -> b) -> a -> c -> b
@@ -21,7 +21,7 @@ const' f a _ = f a
 enumerate :: [a] -> [(Int, a)]
 enumerate = zip [0..]
 
-unimplemented :: Show p => p -> Int
+unimplemented :: (Show p, Show a) => p -> a
 unimplemented = error . show
 
 pair :: [a] -> (a, a)