diff --git a/dumux/porousmediumflow/1pncmin/model.hh b/dumux/porousmediumflow/1pncmin/model.hh
index 397f7079c6c2cdc8593be7b5fe23963a9be9e8b1..d0bf189ceddc30077687871a6fc0811d5cab7825 100644
--- a/dumux/porousmediumflow/1pncmin/model.hh
+++ b/dumux/porousmediumflow/1pncmin/model.hh
@@ -44,7 +44,7 @@ v = - \frac{k_{r}}{\mu} \mathbf{K}
 * The solid or mineral phases are assumed to consist of a single component.
 * Their mass balance consist only of a storage and a source term:
 * \f[
- \frac{\partial \varrho_\lambda \phi_\lambda )} {\partial t} = q_\lambda
+ \frac{\partial ( \varrho_\lambda \phi_\lambda )} {\partial t} = q_\lambda
 * \f]
 *
 * All equations are discretized using a vertex-centered finite volume (box)
diff --git a/dumux/porousmediumflow/2pncmin/model.hh b/dumux/porousmediumflow/2pncmin/model.hh
index 55264597a0bacdef12747db4e7449b683eac4f40..164a5dc8cf737aafe3afa607972a8dfb5f82ebb4 100644
--- a/dumux/porousmediumflow/2pncmin/model.hh
+++ b/dumux/porousmediumflow/2pncmin/model.hh
@@ -48,7 +48,7 @@
  *
  * The solid or mineral phases are assumed to consist of a single component.
  * Their mass balance consist only of a storage and a source term:
- *  \f$\frac{\partial \varrho_\lambda \phi_\lambda )} {\partial t}
+ *  \f$\frac{\partial ( \varrho_\lambda \phi_\lambda )} {\partial t}
  *  = q_\lambda\f$
  *
  * All equations are discretized using a vertex-centered finite volume (box)
diff --git a/dumux/porousmediumflow/mineralization/model.hh b/dumux/porousmediumflow/mineralization/model.hh
index 4891c330152b94467f963588f900f09336549d13..bccfc1a3692e6d004598e647d5016a85fa709a8a 100644
--- a/dumux/porousmediumflow/mineralization/model.hh
+++ b/dumux/porousmediumflow/mineralization/model.hh
@@ -25,7 +25,7 @@
  *
  * The solid or mineral phases are assumed to consist of a single component.
  * Their mass balance consist only of a storage and a source term:
- * \f$\frac{\partial \varrho_\lambda \phi_\lambda )} {\partial t} = q_\lambda\f$
+ * \f$\frac{\partial ( \varrho_\lambda \phi_\lambda )} {\partial t} = q_\lambda\f$
  */
 
 #ifndef DUMUX_MINERALIZATION_MODEL_HH