diff --git a/docs/src/main/tut/typeclasses/monad.md b/docs/src/main/tut/typeclasses/monad.md
index 73f6a520531..f3ba9032b1f 100644
--- a/docs/src/main/tut/typeclasses/monad.md
+++ b/docs/src/main/tut/typeclasses/monad.md
@@ -137,7 +137,13 @@ implicit def optionTMonad[F[_]](implicit F : Monad[F]) = {
         }
       }
     def tailRecM[A, B](a: A)(f: A => OptionT[F, Either[A, B]]): OptionT[F, B] =
-      defaultTailRecM(a)(f)
+      OptionT {
+        F.flatMap(f(a).value) {
+          case None => F.pure(None)
+          case Some(Right(b)) => F.pure(Some(b))
+          case Some(Left(a2)) => tailRecM(a2)(f).value
+        }
+      }
   }
 }
 ```