diff --git a/dune/tectonic/nicefunction.hh b/dune/tectonic/nicefunction.hh
index 95289ddd30ac0dc22b9448fdb66ec478d827b12a..eb9388030a0965439d604b3422ce77b51e084419 100644
--- a/dune/tectonic/nicefunction.hh
+++ b/dune/tectonic/nicefunction.hh
@@ -40,18 +40,18 @@ class NiceFunction {
 
 class RuinaFunction : public NiceFunction {
 public:
-  RuinaFunction(double coefficient, double a, double mu, double V0,
+  RuinaFunction(double coefficient, double a, double mu_0, double V_0,
                 double normalStress, double b, double state, double L)
       : NiceFunction(),
         a(a),
-        V0(V0),
+        V_0(V_0),
         coefficientProduct(coefficient * normalStress),
         // state is assumed to be logarithmic
-        K(mu + b * (state + std::log(V0 / L))),
+        K(mu_0 + b * (state + std::log(V_0 / L))),
         V_m(std::exp(-K / a)) {}
 
   double virtual evaluate(double V) const {
-    double const arg = V / V0;
+    double const arg = V / V_0;
     if (arg <= V_m)
       return 0;
 
@@ -60,7 +60,7 @@ class RuinaFunction : public NiceFunction {
   }
 
   double virtual leftDifferential(double V) const {
-    double const arg = V / V0;
+    double const arg = V / V_0;
     if (arg <= V_m)
       return 0;
 
@@ -74,8 +74,8 @@ class RuinaFunction : public NiceFunction {
 
   double virtual second_deriv(double V) const {
     assert(V >= 0);
-    assert(V0 > 0);
-    double const arg = V / V0;
+    assert(V_0 > 0);
+    double const arg = V / V_0;
     if (arg <= V_m)
       return 0;
 
@@ -84,8 +84,8 @@ class RuinaFunction : public NiceFunction {
 
   double virtual regularity(double V) const {
     assert(V >= 0);
-    assert(V0 > 0);
-    double const arg = V / V0;
+    assert(V_0 > 0);
+    double const arg = V / V_0;
     // TODO: Make this controllable
     if (std::abs(arg - V_m) < 1e-14)
       return std::numeric_limits<double>::infinity();
@@ -97,7 +97,7 @@ class RuinaFunction : public NiceFunction {
 
 private:
   double const a;
-  double const V0;
+  double const V_0;
   double const coefficientProduct;
   double const K;
   double const V_m;