diff --git a/dumux/common/boundarytypes.hh b/dumux/common/boundarytypes.hh
index dbce125fe98e807ca46820353c0b62a16ced8820..5a168b551dd5bfaf82f1393f5810f3c8d649aa44 100644
--- a/dumux/common/boundarytypes.hh
+++ b/dumux/common/boundarytypes.hh
@@ -143,8 +143,7 @@ public:
     }
 
     /*!
-     * \brief Set a Neumann boundary condition for a single a single
-     *        equation.
+     * \brief Set a Neumann boundary condition for a single equation.
      *
      * \param eqIdx The index of the equation
      */
@@ -176,8 +175,7 @@ public:
     }
 
     /*!
-     * \brief Set a Neumann boundary condition for a single a single
-     *        equation.
+     * \brief Set a Neumann boundary condition for a single equation.
      *
      * \param eqIdx The index of the equation on which the outflow
      *              condition applies.
diff --git a/dumux/common/variablesbackend.hh b/dumux/common/variablesbackend.hh
index f9e1d77d78e309e1ade02d98deb87963b3d73537..cb8ea9c7e8f3e740827ebbcb1772deef0caaaea2 100644
--- a/dumux/common/variablesbackend.hh
+++ b/dumux/common/variablesbackend.hh
@@ -84,7 +84,7 @@ public:
  *   - default-constructible
  *   - has size() member
  *   - has resize(0) member
- *   - has axpy(a, x) member 
+ *   - has axpy(a, x) member
  */
 template<class Vector>
 class DofBackend<Vector, false>
diff --git a/dumux/porousmediumflow/sequential/boundarytypes.hh b/dumux/porousmediumflow/sequential/boundarytypes.hh
index a00c06d417553c0adcc8f20c4d0bfb15b5859c91..24b43fe4ebcac0d2839fa4e1fb73e1cb5eaea8f1 100644
--- a/dumux/porousmediumflow/sequential/boundarytypes.hh
+++ b/dumux/porousmediumflow/sequential/boundarytypes.hh
@@ -75,9 +75,7 @@ public:
     }
 
     /*!
-     * \brief Set a Neumann boundary condition for a single a single
-     *        equation.
-     *
+     * \brief Set a Neumann boundary condition for a single equation.
      * \param eqIdx The index of the equation on which the outflow
      *              condition applies.
      */