diff --git a/src/Data/Heap.hs b/src/Data/Heap.hs
index 177f608..44bcae3 100644
--- a/src/Data/Heap.hs
+++ b/src/Data/Heap.hs
@@ -64,8 +64,7 @@ adjust :: Addr -> (a -> a) -> Heap a -> Heap a
 adjust k f (Heap u m) = Heap u (M.adjust f k m)
 
 free :: Addr -> Heap a -> Heap a
-free k (Heap u m) = Heap (k:u) (M.delete k' m)
-    where k' = k -- trace ("free " <> show k) k
+free k (Heap u m) = Heap (k:u) (M.delete k m)
 
 hLookup :: Addr -> Heap a -> Maybe a
 hLookup k (Heap _ m) = m !? k
diff --git a/src/TIM.hs b/src/TIM.hs
index b883d82..43cd022 100644
--- a/src/TIM.hs
+++ b/src/TIM.hs
@@ -16,7 +16,6 @@ import System.IO                (Handle, hPutStr)
 import Text.Printf              (printf, hPrintf)
 import Data.Proxy               (Proxy(..))
 import Data.Monoid              (Endo(..))
-import Debug.Trace              (trace)
 import Lens.Micro
 import Lens.Micro.TH
 import Data.Pretty