diff --git a/a4/src/APL/Monad.hs b/a4/src/APL/Monad.hs
index 8bdcce1..3bdf3f7 100644
--- a/a4/src/APL/Monad.hs
+++ b/a4/src/APL/Monad.hs
@@ -119,7 +119,7 @@ failure :: String -> EvalM a
 failure = Free . ErrorOp
 
 catch :: EvalM a -> EvalM a -> EvalM a
-catch = error "TODO"
+catch m1 m2 = Free $ TryCatchOp m1 m2
 
 evalKvGet :: Val -> EvalM Val
 evalKvGet = error "TODO"