diff --git a/ci/release/template/man/d2.1 b/ci/release/template/man/d2.1
index 80beb44d7..6000ffc56 100644
--- a/ci/release/template/man/d2.1
+++ b/ci/release/template/man/d2.1
@@ -66,6 +66,9 @@ Port listening address when used with
 .It Fl t , -theme Ar 0
 Set the diagram theme ID
 .Ns .
+.It Fl t , -dark-theme Ar 0
+the diagram dark theme ID. When left unset only the theme will be applied
+.Ns .
 .It Fl s , -sketch Ar false
 Renders the diagram to look like it was sketched by hand
 .Ns .