diff --git a/tests/composite_viscous_outputs.cc b/tests/composite_viscous_outputs.cc
index 866c7787bdf..0cec200924d 100644
--- a/tests/composite_viscous_outputs.cc
+++ b/tests/composite_viscous_outputs.cc
@@ -47,6 +47,7 @@ void f(const aspect::SimulatorAccess<dim> &simulator_access,
   composite_creep = std::make_unique<Rheology::CompositeViscoPlastic<dim>>();
   composite_creep->initialize_simulator (simulator_access.get_simulator());
   composite_creep->declare_parameters(prm);
+  prm.set("Viscosity averaging scheme", "isostrain");
   prm.set("Include diffusion creep in composite rheology", "true");
   prm.set("Include dislocation creep in composite rheology", "true");
   prm.set("Include Peierls creep in composite rheology", "true");
diff --git a/tests/composite_viscous_outputs_isostress.cc b/tests/composite_viscous_outputs_isostress.cc
index d7be34de6aa..a1dd2ad1697 100644
--- a/tests/composite_viscous_outputs_isostress.cc
+++ b/tests/composite_viscous_outputs_isostress.cc
@@ -50,7 +50,6 @@ void f(const aspect::SimulatorAccess<dim> &simulator_access,
   composite_creep = std::make_unique<Rheology::CompositeViscoPlastic<dim>>();
   composite_creep->initialize_simulator (simulator_access.get_simulator());
   composite_creep->declare_parameters(prm);
-
   prm.set("Viscosity averaging scheme", "isostress");
   prm.set("Include diffusion creep in composite rheology", "true");
   prm.set("Include dislocation creep in composite rheology", "true");
diff --git a/tests/composite_viscous_outputs_no_peierls.cc b/tests/composite_viscous_outputs_no_peierls.cc
index 4eb991845ac..6d3078eabb0 100644
--- a/tests/composite_viscous_outputs_no_peierls.cc
+++ b/tests/composite_viscous_outputs_no_peierls.cc
@@ -47,6 +47,7 @@ void f(const aspect::SimulatorAccess<dim> &simulator_access,
   composite_creep = std::make_unique<Rheology::CompositeViscoPlastic<dim>>();
   composite_creep->initialize_simulator (simulator_access.get_simulator());
   composite_creep->declare_parameters(prm);
+  prm.set("Viscosity averaging scheme", "isostrain");
   prm.set("Include diffusion creep in composite rheology", "true");
   prm.set("Include dislocation creep in composite rheology", "true");
   prm.set("Include Peierls creep in composite rheology", "false");