diff --git a/theories/Data/Monads/EitherMonad.v b/theories/Data/Monads/EitherMonad.v
index 8c9a53b..8c50460 100644
--- a/theories/Data/Monads/EitherMonad.v
+++ b/theories/Data/Monads/EitherMonad.v
@@ -90,12 +90,12 @@ Section except.
       | (inl l, _) => ret (inl l)
       | (inr a, t) => ret (inr (a, t))
     end)
-  ; pass := fun _ c => mkEitherT (
+  ; pass := fun _ c => mkEitherT (pass (
     x <- unEitherT c ;;
     match x with
-      | inl s => ret (inl s)
-      | inr (a,f) => pass (ret (inr a, f))
-    end)
+      | inl s => ret (inl s, fun x => x)
+      | inr (a, f) => ret (inr a, f)
+    end))
   }.
 
   Global Instance MonadFix_eitherT (MF : MonadFix m) : MonadFix eitherT :=
diff --git a/theories/Data/Monads/StateMonad.v b/theories/Data/Monads/StateMonad.v
index 2448584..73130bb 100644
--- a/theories/Data/Monads/StateMonad.v
+++ b/theories/Data/Monads/StateMonad.v
@@ -79,8 +79,8 @@ Section StateType.
   ; listen := fun _ c => mkStateT (fun s => bind (listen (runStateT c s))
     (fun x => let '(a,s,t) := x in
     ret (a,t,s)))
-  ; pass := fun _ c => mkStateT (fun s => bind (runStateT c s) (fun x =>
-    let '(a,t,s) := x in pass (ret ((a,s),t))))
+  ; pass := fun _ c => mkStateT (fun s => pass (bind (runStateT c s) (fun x =>
+    let '(a,t,s) := x in ret ((a,s),t))))
   }.
 
   Global Instance Exc_stateT T (MR : MonadExc T m) : MonadExc T stateT :=