diff --git a/src/assemblers.cc b/src/assemblers.cc
index 63de8a59312fdb0f6008e4a8c2c64390eb9fefb0..3b5d298bb4d22dda6d63dc282d113a2a53a68a82 100644
--- a/src/assemblers.cc
+++ b/src/assemblers.cc
@@ -59,8 +59,8 @@ assemble_nonlinearity(
 
   typedef Dune::BlockVector<Dune::FieldVector<double, 1>> SingletonVectorType;
   // {{{ Assemble terms for the nonlinearity
-  SingletonVectorType mu(size);
-  mu = parset.get<double>("mu");
+  SingletonVectorType mu0(size);
+  mu0 = parset.get<double>("mu0");
 
   SingletonVectorType a(size);
   a = parset.get<double>("a");
@@ -76,7 +76,7 @@ assemble_nonlinearity(
 
   return Dune::make_shared<
       Dune::GlobalRuinaNonlinearity<MatrixType, VectorType> const>(
-      nodalIntegrals, a, mu, V0, normalStress, b, state, L);
+      nodalIntegrals, a, mu0, V0, normalStress, b, state, L);
 }
 
 #include "assemblers_tmpl.cc"