diff --git a/docs/book/src/cronjob-tutorial/testdata/project/internal/controller/cronjob_controller.go b/docs/book/src/cronjob-tutorial/testdata/project/internal/controller/cronjob_controller.go
index 1fb390bc66a..5b1adaa526e 100644
--- a/docs/book/src/cronjob-tutorial/testdata/project/internal/controller/cronjob_controller.go
+++ b/docs/book/src/cronjob-tutorial/testdata/project/internal/controller/cronjob_controller.go
@@ -60,7 +60,7 @@ type realClock struct{}
 
 func (_ realClock) Now() time.Time { return time.Now() }
 
-// clock knows how to get the current time.
+// Clock knows how to get the current time.
 // It can be used to fake out timing for testing.
 type Clock interface {
 	Now() time.Time
diff --git a/hack/docs/internal/cronjob-tutorial/controller_implementation.go b/hack/docs/internal/cronjob-tutorial/controller_implementation.go
index fed8c7c55b3..7bb03aad4a4 100644
--- a/hack/docs/internal/cronjob-tutorial/controller_implementation.go
+++ b/hack/docs/internal/cronjob-tutorial/controller_implementation.go
@@ -57,7 +57,7 @@ type realClock struct{}
 
 func (_ realClock) Now() time.Time { return time.Now() }
 
-// clock knows how to get the current time.
+// Clock knows how to get the current time.
 // It can be used to fake out timing for testing.
 type Clock interface {
 	Now() time.Time