diff --git a/src/assemblers.cc b/src/assemblers.cc
index f8485a49c7e98338f0625d676451230c168d7944..972c5512491b2e00e34efcdc283bead6def13e46 100644
--- a/src/assemblers.cc
+++ b/src/assemblers.cc
@@ -12,6 +12,10 @@
 
 #include "assemblers.hh"
 
+#include "enums.hh"
+#include "enum_parser.cc"
+#include "enum_model.cc"
+
 // Assembles Neumann boundary term in f
 template <class GridType, class GridView, class LocalVectorType, class FEBasis>
 void assemble_neumann(GridView const &gridView, FEBasis const &feBasis,
@@ -67,34 +71,32 @@ assemble_nonlinearity(
   auto normalStress = Dune::make_shared<SingletonVectorType>(size);
   *normalStress = parset.get<double>("normalstress");
 
-  std::string const friction_model = parset.get<std::string>("model");
-  if (friction_model == std::string("Ruina")) {
-    auto a = Dune::make_shared<SingletonVectorType>(size);
-    *a = parset.get<double>("ruina.a");
-
-    auto eta = Dune::make_shared<SingletonVectorType>(size);
-    *eta = parset.get<double>("eta");
-
-    auto b = Dune::make_shared<SingletonVectorType>(size);
-    *b = parset.get<double>("ruina.b");
-
-    auto L = Dune::make_shared<SingletonVectorType>(size);
-    *L = parset.get<double>("ruina.L");
-
-    return Dune::make_shared<
-        Dune::GlobalRuinaNonlinearity<VectorType, MatrixType> const>(
-        nodalIntegrals, a, mu, eta, normalStress, b, state, L, h);
-  } else if (friction_model == std::string("Laursen")) {
-    return
-        // TODO: take state and h into account
-        // FIXME: We should be using a quadratic rather than a linear function
-        // here!
-        Dune::make_shared<
-            Dune::GlobalLaursenNonlinearity<Dune::LinearFunction, VectorType,
-                                            MatrixType> const>(mu, normalStress,
-                                                               nodalIntegrals);
-  } else {
-    assert(false);
+  switch (parset.get<Config::model>("model")) {
+    case Config::Exponential: {
+      auto a = Dune::make_shared<SingletonVectorType>(size);
+      *a = parset.get<double>("ruina.a");
+
+      auto eta = Dune::make_shared<SingletonVectorType>(size);
+      *eta = parset.get<double>("eta");
+
+      auto b = Dune::make_shared<SingletonVectorType>(size);
+      *b = parset.get<double>("ruina.b");
+
+      auto L = Dune::make_shared<SingletonVectorType>(size);
+      *L = parset.get<double>("ruina.L");
+
+      return Dune::make_shared<
+          Dune::GlobalRuinaNonlinearity<VectorType, MatrixType> const>(
+          nodalIntegrals, a, mu, eta, normalStress, b, state, L, h);
+    }
+    case Config::Laursen:
+      return
+          // TODO: take state and h into account
+          // FIXME: We should be using a quadratic rather than a linear function
+          // here!
+          Dune::make_shared<Dune::GlobalLaursenNonlinearity<
+              Dune::LinearFunction, VectorType,
+              MatrixType> const>(mu, normalStress, nodalIntegrals);
   }
 }
 
diff --git a/src/enum_model.cc b/src/enum_model.cc
new file mode 100644
index 0000000000000000000000000000000000000000..1fd1bc1d525bc6ef678823c00487dfb66a2968bf
--- /dev/null
+++ b/src/enum_model.cc
@@ -0,0 +1,13 @@
+#include <dune/common/exceptions.hh>
+
+template <> struct StringToEnum<Config::model> {
+  static Config::model convert(std::string const &s) {
+    if (s == "Laursen")
+      return Config::Laursen;
+
+    if (s == "Exponential")
+      return Config::Exponential;
+
+    DUNE_THROW(Dune::Exception, "failed to parse enum");
+  }
+};
diff --git a/src/enums.hh b/src/enums.hh
index ce43a1f05d5575f2041c770b911c35373fa862ec..d182db67c7c5e6433fa61dbe741192747b31fdd4 100644
--- a/src/enums.hh
+++ b/src/enums.hh
@@ -1,4 +1,8 @@
 struct Config {
+  enum model {
+    Laursen,
+    Exponential
+  };
   enum state_model {
     Dieterich,
     Ruina
diff --git a/src/one-body-sample.parset b/src/one-body-sample.parset
index 58fa7b7968e0fbe8053b492eca340e172e5447c7..1e89999d0b571c28d8d9418228fce2e6c32fb4cb 100644
--- a/src/one-body-sample.parset
+++ b/src/one-body-sample.parset
@@ -68,7 +68,7 @@ normalstress = 0.1 # laursen depends a lot more on this
 #    http://earthquake.usgs.gov/research/physics/lab/prediction.pdf
 mu = 0.5
 eta = 1
-model = Ruina
+model = Exponential
 
 [boundary.friction.state]
 evolve = true