diff --git a/cogl/cogl-quaternion.h b/cogl/cogl-quaternion.h
index b90fde8a1..1ec982593 100644
--- a/cogl/cogl-quaternion.h
+++ b/cogl/cogl-quaternion.h
@@ -258,6 +258,13 @@ void
 cogl_quaternion_init_from_euler (CoglQuaternion *quaternion,
                                  const CoglEuler *euler);
 
+/**
+ * cogl_quaternion_init_from_quaternion:
+ * @quaternion: A #CoglQuaternion
+ * @src: A #CoglQuaternion with which to initialize @quaternion
+ *
+ * Since: 2.0
+ */
 void
 cogl_quaternion_init_from_quaternion (CoglQuaternion *quaternion,
                                       CoglQuaternion *src);
diff --git a/doc/reference/cogl-2.0-experimental/cogl-2.0-experimental-sections.txt b/doc/reference/cogl-2.0-experimental/cogl-2.0-experimental-sections.txt
index 741bd7441..acc0eaec0 100644
--- a/doc/reference/cogl-2.0-experimental/cogl-2.0-experimental-sections.txt
+++ b/doc/reference/cogl-2.0-experimental/cogl-2.0-experimental-sections.txt
@@ -583,6 +583,7 @@ cogl_euler_free
 CoglQuaternion
 cogl_quaternion_init_identity
 cogl_quaternion_init
+cogl_quaternion_init_from_quaternion
 cogl_quaternion_init_from_angle_vector
 cogl_quaternion_init_from_array
 cogl_quaternion_init_from_x_rotation