diff --git a/dune/dorie/model/richards/parameterization/scaling.hh b/dune/dorie/model/richards/parameterization/scaling.hh
index 5830cf93df532eecc89af9d91d2b295fb2d8239f..87dd0696f57bedd0556085e00aebba3385029ec1 100644
--- a/dune/dorie/model/richards/parameterization/scaling.hh
+++ b/dune/dorie/model/richards/parameterization/scaling.hh
@@ -151,7 +151,7 @@ protected:
  *  reference length scale of the medium.
  *
  *  \f{align*}{
- *      h_m &= h_m^* \cdot \xi \\
+ *      h_m &= h_m^* \cdot \xi^{-1} \\
  *      K &= K^* \cdot \xi^2
  *  \f}
  *