diff --git a/docs/src/main/tut/datatypes/state.md b/docs/src/main/tut/datatypes/state.md
index 1dc328c8d0..10f9682133 100644
--- a/docs/src/main/tut/datatypes/state.md
+++ b/docs/src/main/tut/datatypes/state.md
@@ -282,8 +282,8 @@ So, let's model our typed door:
 import cats.Eval
 import cats.data.IndexedStateT
 
-def open: IndexedStateT[Eval, Open.type, Closed.type, Unit] = IndexedStateT.set(Closed)
-def close: IndexedStateT[Eval, Closed.type, Open.type, Unit] = IndexedStateT.set(Open)
+def open: IndexedStateT[Eval, Closed.type, Open.type, Unit] = IndexedStateT.set(Open)
+def close: IndexedStateT[Eval, Open.type, Closed.type, Unit] = IndexedStateT.set(Closed)
 ```
 
 We can now reject, at compile time, sequences of `open` and `close` that are invalid:
@@ -305,3 +305,11 @@ val valid = for {
 ```
 
 Note that the inferred type of `valid` correctly models that this computation can be executed only with an initial `Closed` state.
+
+```tut:book:fail
+valid.run(Open)
+```
+
+```tut:book
+valid.run(Closed)
+```
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