diff --git a/docs/src/main/tut/invariantmonoidal.md b/docs/src/main/tut/invariantmonoidal.md
index b2a54936c6..9137b3d38e 100644
--- a/docs/src/main/tut/invariantmonoidal.md
+++ b/docs/src/main/tut/invariantmonoidal.md
@@ -60,7 +60,7 @@ implicit val fooSemigroup: Semigroup[Foo] = (
 
 Our new Semigroup in action:
 
-```tut
+```tut:book
 Foo("Hello", List(0.0)) |+| Foo("World", Nil) |+| Foo("!", List(1.1, 2.2))
 ```
 
@@ -178,7 +178,7 @@ val fooCodec: CsvCodec[Foo] = (
 
 Finally let's verify out CsvCodec law with an example:
 
-```tut
+```tut:book
 val foo = Foo("foo", BinDec(10, 10), BinDec(20, 20))
 
 val fooCsv = fooCodec.write(foo)