diff --git a/exe/GarnetRs/Wrapped.hs b/exe/GarnetRs/Wrapped.hs
index cb4d44c..a7633db 100644
--- a/exe/GarnetRs/Wrapped.hs
+++ b/exe/GarnetRs/Wrapped.hs
@@ -21,6 +21,7 @@ import Foreign.C
 import GarnetRs qualified as Raw
 import GarnetRs.Safe qualified as Raw
 import HsBindgen.Runtime.PtrConst
+import System.IO.Unsafe
 
 data T = T
     { a :: Bool
@@ -65,5 +66,5 @@ helloShape = Raw.hello_shape . convertShape
 add :: Int64 -> Int64 -> Int64
 add = Raw.add
 
-sumTree :: BTree Int64 -> IO Int64
-sumTree = flip withBTree Raw.sum_tree
+sumTree :: BTree Int64 -> Int64
+sumTree = unsafePerformIO . flip withBTree Raw.sum_tree
diff --git a/exe/Main.hs b/exe/Main.hs
index 7e3bee8..e950324 100644
--- a/exe/Main.hs
+++ b/exe/Main.hs
@@ -10,4 +10,4 @@ main = do
     helloShape $ Circle 3.14
     helloShape $ Rectangle 10.0 5.0
     putStrLn $ "3 + 4 = " <> show (add 3 4)
-    putStrLn . ("Tree sum: " <>) . show =<< sumTree (Fork (Fork (Leaf 1) (Fork (Leaf 2) (Leaf 3))) (Leaf 4))
+    putStrLn $ "Tree sum: " <> show (sumTree (Fork (Fork (Leaf 1) (Fork (Leaf 2) (Leaf 3))) (Leaf 4)))