diff --git a/api/v1beta2/git.go b/api/v1beta2/git.go
index 057e2fff..7fc647a6 100644
--- a/api/v1beta2/git.go
+++ b/api/v1beta2/git.go
@@ -70,6 +70,7 @@ type CommitSpec struct {
 
 	// MessageTemplateValues provides additional values to be available to the
 	// templating rendering.
+	// +optional
 	MessageTemplateValues map[string]string `json:"messageTemplateValues,omitempty"`
 }
 
diff --git a/docs/api/v1beta2/image-automation.md b/docs/api/v1beta2/image-automation.md
index 3ac1c78b..9ebf3ba9 100644
--- a/docs/api/v1beta2/image-automation.md
+++ b/docs/api/v1beta2/image-automation.md
@@ -78,6 +78,7 @@ map[string]string
 </em>
 </td>
 <td>
+<em>(Optional)</em>
 <p>MessageTemplateValues provides additional values to be available to the
 templating rendering.</p>
 </td>