diff --git a/dumux/implicit/mpnc/energy/mpncindicesenergy.hh b/dumux/implicit/mpnc/energy/mpncindicesenergy.hh
index 29d12f8e2464256f7525d77be871e31a5a69e62e..9d76fce83cfabe2b13c96163bd42fe316d54c910 100644
--- a/dumux/implicit/mpnc/energy/mpncindicesenergy.hh
+++ b/dumux/implicit/mpnc/energy/mpncindicesenergy.hh
@@ -47,7 +47,10 @@ public:
      * \brief This module does not define any primary variables in the
      *        isothermal case.
      */
-    static const unsigned int NumPrimaryVars = 0;
+    static const unsigned int numPrimaryVars = 0;
+
+    DUNE_DEPRECATED_MSG("use numPrimaryVars (uncapitalized 'n') instead") 
+    static const unsigned int NumPrimaryVars = numPrimaryVars; //!< \deprecated
 };
 
 /*!
@@ -62,7 +65,10 @@ public:
     /*!
      * \brief This module defines one new primary variable.
      */
-    static const unsigned int NumPrimaryVars = 1;
+    static const unsigned int numPrimaryVars = 1;
+
+    DUNE_DEPRECATED_MSG("use numPrimaryVars (uncapitalized 'n') instead") 
+    static const unsigned int NumPrimaryVars = numPrimaryVars; //!< \deprecated
 
     /*!
      * \brief Index for the temperature in a vector of primary
diff --git a/dumux/implicit/mpnc/energy/mpncvolumevariablesenergy.hh b/dumux/implicit/mpnc/energy/mpncvolumevariablesenergy.hh
index 067068b9507728a83b1c6805d1802cfb000260b4..8a4113139075e5f7bf190f1ad991a3e19a63a129 100644
--- a/dumux/implicit/mpnc/energy/mpncvolumevariablesenergy.hh
+++ b/dumux/implicit/mpnc/energy/mpncvolumevariablesenergy.hh
@@ -119,7 +119,7 @@ class MPNCVolumeVariablesEnergy<TypeTag, /*enableEnergy=*/true, /*kineticEnergyT
     enum { numPhases        = GET_PROP_VALUE(TypeTag, NumPhases) };
     enum { numComponents    = GET_PROP_VALUE(TypeTag, NumComponents) };
     enum { temperatureIdx   = Indices::temperatureIdx };
-    enum { numEnergyEqs     = Indices::NumPrimaryEnergyVars};
+    enum { numEnergyEqs     = Indices::numPrimaryEnergyVars};
     enum { temperature0Idx = Indices::temperatureIdx };
 
     typedef typename GET_PROP_TYPE(TypeTag, FluidSystem) FluidSystem;
diff --git a/dumux/implicit/mpnc/mass/mpncindicesmass.hh b/dumux/implicit/mpnc/mass/mpncindicesmass.hh
index e4b97f7039b91d4326932da75f9635932ebfb2ee..24e723b70c1629aecbe7ee1298f043812b4539a9 100644
--- a/dumux/implicit/mpnc/mass/mpncindicesmass.hh
+++ b/dumux/implicit/mpnc/mass/mpncindicesmass.hh
@@ -51,7 +51,10 @@ public:
     /*!
      * \brief This module defines one new primary variable.
      */
-    static const unsigned int NumPrimaryVars = numComponents;
+    static const unsigned int numPrimaryVars = numComponents;
+
+    DUNE_DEPRECATED_MSG("use numPrimaryVars (uncapitalized 'n') instead") 
+    static const unsigned int NumPrimaryVars = numPrimaryVars; //!< \deprecated
 
     /*!
      * \brief Index for the fugacity of the first component in the
diff --git a/dumux/implicit/mpnc/mpncindices.hh b/dumux/implicit/mpnc/mpncindices.hh
index 277d0098ee7db7d3556a4faf77f1211f7cf399ba..5e7dc80aa9bfa294ad3d30e8d5e529bb0dfb093b 100644
--- a/dumux/implicit/mpnc/mpncindices.hh
+++ b/dumux/implicit/mpnc/mpncindices.hh
@@ -55,7 +55,7 @@ struct MPNCIndices :
                                TypeTag,
                                GET_PROP_VALUE(TypeTag, EnableKinetic) >,
         public MPNCEnergyIndices<BasePVOffset +
-                                 MPNCMassIndices<0, TypeTag, GET_PROP_VALUE(TypeTag, EnableKinetic) >::NumPrimaryVars,
+                                 MPNCMassIndices<0, TypeTag, GET_PROP_VALUE(TypeTag, EnableKinetic) >::numPrimaryVars,
                                  GET_PROP_VALUE(TypeTag, EnableEnergy),
                                  GET_PROP_VALUE(TypeTag, EnableKineticEnergy)>
 {
@@ -67,23 +67,29 @@ private:
             enum { numPhases = FluidSystem::numPhases };
 
             typedef MPNCMassIndices<BasePVOffset, TypeTag, enableKinetic> MassIndices;
-            typedef MPNCEnergyIndices<BasePVOffset + MassIndices::NumPrimaryVars, enableEnergy, enableKineticEnergy> EnergyIndices;
+            typedef MPNCEnergyIndices<BasePVOffset + MassIndices::numPrimaryVars, enableEnergy, enableKineticEnergy> EnergyIndices;
 
 public:
     /*!
      * \brief The number of primary variables / equations.
      */
     // temperature + Mass Balance  + constraints for switch stuff
-    static const unsigned int NumPrimaryVars =
-        MassIndices::NumPrimaryVars +
-        EnergyIndices::NumPrimaryVars +
+    static const unsigned int numPrimaryVars =
+        MassIndices::numPrimaryVars +
+        EnergyIndices::numPrimaryVars +
         numPhases;
 
+    DUNE_DEPRECATED_MSG("use numPrimaryVars (uncapitalized 'n') instead") 
+    static const unsigned int NumPrimaryVars = numPrimaryVars; //!< \deprecated
+
     /*!
      * \brief The number of primary variables / equations of the energy module.
      */
-    static const unsigned int NumPrimaryEnergyVars =
-        EnergyIndices::NumPrimaryVars ;
+    static const unsigned int numPrimaryEnergyVars =
+        EnergyIndices::numPrimaryVars ;
+
+    DUNE_DEPRECATED_MSG("use numPrimaryEnergyVars (uncapitalized 'n') instead") 
+    static const unsigned int NumPrimaryEnergyVars = numPrimaryEnergyVars; //!< \deprecated
 
     /*!
      * \brief Index of the saturation of the first phase in a vector
@@ -93,8 +99,8 @@ public:
      * saturations for the phases [1, ..., numPhases - 1]
      */
     static const unsigned int s0Idx =
-        MassIndices::NumPrimaryVars +
-        EnergyIndices::NumPrimaryVars;
+        MassIndices::numPrimaryVars +
+        EnergyIndices::numPrimaryVars;
 
     DUNE_DEPRECATED_MSG("use s0Idx (uncapitalized 's') instead") 
     static const int S0Idx = s0Idx; //!< \deprecated index of the saturation of the first phase
@@ -104,8 +110,8 @@ public:
      *        primary variables.
      */
     static const unsigned int p0Idx =
-        MassIndices::NumPrimaryVars +
-        EnergyIndices::NumPrimaryVars +
+        MassIndices::numPrimaryVars +
+        EnergyIndices::numPrimaryVars +
         numPhases - 1;
 
     /*!
@@ -114,8 +120,8 @@ public:
      * The index for the remaining phases are consecutive.
      */
     static const unsigned int phase0NcpIdx =
-        MassIndices::NumPrimaryVars +
-        EnergyIndices::NumPrimaryVars;
+        MassIndices::numPrimaryVars +
+        EnergyIndices::numPrimaryVars;
 };
 
 }
diff --git a/dumux/implicit/mpnc/mpncpropertydefaults.hh b/dumux/implicit/mpnc/mpncpropertydefaults.hh
index c1b7115d9fe95951d8e4cffbdbe87b2e3eaa343e..96d4eb6b6fa8cec78e290d2319ef2d5ebc1023c2 100644
--- a/dumux/implicit/mpnc/mpncpropertydefaults.hh
+++ b/dumux/implicit/mpnc/mpncpropertydefaults.hh
@@ -87,7 +87,7 @@ private:
     typedef typename GET_PROP_TYPE(TypeTag, Indices) Indices;
 
 public:
-    static const unsigned int value = Indices::NumPrimaryVars;
+    static const unsigned int value = Indices::numPrimaryVars;
 };
 
 /*!