diff --git a/doc/TutorialGeometry.dox b/doc/TutorialGeometry.dox
index b3c860d53..ef1c7a506 100644
--- a/doc/TutorialGeometry.dox
+++ b/doc/TutorialGeometry.dox
@@ -152,7 +152,7 @@ OpenGL compatibility \b 3D </td><td>\code
 glLoadMatrixf(t.data());\endcode</td></tr>
 <tr><td>
 OpenGL compatibility \b 2D </td><td>\code
-Transform3f aux(Transform3f::Identity);
+Transform3f aux(Transform3f::Identity());
 aux.linear().corner<2,2>(TopLeft) = t.linear();
 aux.translation().start<2>() = t.translation();
 glLoadMatrixf(aux.data());\endcode</td></tr>