diff --git a/ProcessLib/ThermoMechanics/LocalAssemblerInterface.h b/ProcessLib/ThermoMechanics/LocalAssemblerInterface.h
new file mode 100644
index 0000000000000000000000000000000000000000..d76ebedadf84378d99a3e27ebc8876b7654b10cd
--- /dev/null
+++ b/ProcessLib/ThermoMechanics/LocalAssemblerInterface.h
@@ -0,0 +1,99 @@
+/**
+ * \copyright
+ * Copyright (c) 2012-2017, OpenGeoSys Community (http://www.opengeosys.org)
+ *            Distributed under a Modified BSD License.
+ *              See accompanying file LICENSE.txt or
+ *              http://www.opengeosys.org/project/license
+ *
+ */
+
+#pragma once
+
+#include <vector>
+
+#include "NumLib/Extrapolation/ExtrapolatableElement.h"
+#include "ProcessLib/LocalAssemblerInterface.h"
+
+namespace ProcessLib
+{
+namespace ThermoMechanics
+{
+struct ThermoMechanicsLocalAssemblerInterface
+    : public ProcessLib::LocalAssemblerInterface,
+      public NumLib::ExtrapolatableElement
+{
+    virtual std::vector<double> const& getIntPtSigmaXX(
+        const double /*t*/,
+        GlobalVector const& /*current_solution*/,
+        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
+        std::vector<double>& cache) const = 0;
+
+    virtual std::vector<double> const& getIntPtSigmaYY(
+        const double /*t*/,
+        GlobalVector const& /*current_solution*/,
+        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
+        std::vector<double>& cache) const = 0;
+
+    virtual std::vector<double> const& getIntPtSigmaZZ(
+        const double /*t*/,
+        GlobalVector const& /*current_solution*/,
+        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
+        std::vector<double>& cache) const = 0;
+
+    virtual std::vector<double> const& getIntPtSigmaXY(
+        const double /*t*/,
+        GlobalVector const& /*current_solution*/,
+        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
+        std::vector<double>& cache) const = 0;
+
+    virtual std::vector<double> const& getIntPtSigmaXZ(
+        const double /*t*/,
+        GlobalVector const& /*current_solution*/,
+        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
+        std::vector<double>& cache) const = 0;
+
+    virtual std::vector<double> const& getIntPtSigmaYZ(
+        const double /*t*/,
+        GlobalVector const& /*current_solution*/,
+        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
+        std::vector<double>& cache) const = 0;
+
+    virtual std::vector<double> const& getIntPtEpsilonXX(
+        const double /*t*/,
+        GlobalVector const& /*current_solution*/,
+        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
+        std::vector<double>& cache) const = 0;
+
+    virtual std::vector<double> const& getIntPtEpsilonYY(
+        const double /*t*/,
+        GlobalVector const& /*current_solution*/,
+        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
+        std::vector<double>& cache) const = 0;
+
+    virtual std::vector<double> const& getIntPtEpsilonZZ(
+        const double /*t*/,
+        GlobalVector const& /*current_solution*/,
+        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
+        std::vector<double>& cache) const = 0;
+
+    virtual std::vector<double> const& getIntPtEpsilonXY(
+        const double /*t*/,
+        GlobalVector const& /*current_solution*/,
+        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
+        std::vector<double>& cache) const = 0;
+
+    virtual std::vector<double> const& getIntPtEpsilonXZ(
+        const double /*t*/,
+        GlobalVector const& /*current_solution*/,
+        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
+        std::vector<double>& cache) const = 0;
+
+    virtual std::vector<double> const& getIntPtEpsilonYZ(
+        const double /*t*/,
+        GlobalVector const& /*current_solution*/,
+        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
+        std::vector<double>& cache) const = 0;
+};
+
+}  // namespace ThermoMechanics
+}  // namespace ProcessLib
diff --git a/ProcessLib/ThermoMechanics/ThermoMechanicsFEM.h b/ProcessLib/ThermoMechanics/ThermoMechanicsFEM.h
index f01984566ecc941f2e7a2d07afb17c028e2d9dc5..04541118cf996e3f297caa3d9fd05010f6dab727 100644
--- a/ProcessLib/ThermoMechanics/ThermoMechanicsFEM.h
+++ b/ProcessLib/ThermoMechanics/ThermoMechanicsFEM.h
@@ -99,83 +99,6 @@ struct SecondaryData
     std::vector<ShapeMatrixType, Eigen::aligned_allocator<ShapeMatrixType>> N;
 };
 
-struct ThermoMechanicsLocalAssemblerInterface
-    : public ProcessLib::LocalAssemblerInterface,
-      public NumLib::ExtrapolatableElement
-{
-    virtual std::vector<double> const& getIntPtSigmaXX(
-        const double /*t*/,
-        GlobalVector const& /*current_solution*/,
-        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
-        std::vector<double>& cache) const = 0;
-
-    virtual std::vector<double> const& getIntPtSigmaYY(
-        const double /*t*/,
-        GlobalVector const& /*current_solution*/,
-        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
-        std::vector<double>& cache) const = 0;
-
-    virtual std::vector<double> const& getIntPtSigmaZZ(
-        const double /*t*/,
-        GlobalVector const& /*current_solution*/,
-        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
-        std::vector<double>& cache) const = 0;
-
-    virtual std::vector<double> const& getIntPtSigmaXY(
-        const double /*t*/,
-        GlobalVector const& /*current_solution*/,
-        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
-        std::vector<double>& cache) const = 0;
-
-    virtual std::vector<double> const& getIntPtSigmaXZ(
-        const double /*t*/,
-        GlobalVector const& /*current_solution*/,
-        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
-        std::vector<double>& cache) const = 0;
-
-    virtual std::vector<double> const& getIntPtSigmaYZ(
-        const double /*t*/,
-        GlobalVector const& /*current_solution*/,
-        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
-        std::vector<double>& cache) const = 0;
-
-    virtual std::vector<double> const& getIntPtEpsilonXX(
-        const double /*t*/,
-        GlobalVector const& /*current_solution*/,
-        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
-        std::vector<double>& cache) const = 0;
-
-    virtual std::vector<double> const& getIntPtEpsilonYY(
-        const double /*t*/,
-        GlobalVector const& /*current_solution*/,
-        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
-        std::vector<double>& cache) const = 0;
-
-    virtual std::vector<double> const& getIntPtEpsilonZZ(
-        const double /*t*/,
-        GlobalVector const& /*current_solution*/,
-        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
-        std::vector<double>& cache) const = 0;
-
-    virtual std::vector<double> const& getIntPtEpsilonXY(
-        const double /*t*/,
-        GlobalVector const& /*current_solution*/,
-        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
-        std::vector<double>& cache) const = 0;
-
-    virtual std::vector<double> const& getIntPtEpsilonXZ(
-        const double /*t*/,
-        GlobalVector const& /*current_solution*/,
-        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
-        std::vector<double>& cache) const = 0;
-
-    virtual std::vector<double> const& getIntPtEpsilonYZ(
-        const double /*t*/,
-        GlobalVector const& /*current_solution*/,
-        NumLib::LocalToGlobalIndexMap const& /*dof_table*/,
-        std::vector<double>& cache) const = 0;
-};
-
 template <typename ShapeFunction, typename IntegrationMethod,
           int DisplacementDim>
 class ThermoMechanicsLocalAssembler
diff --git a/ProcessLib/ThermoMechanics/ThermoMechanicsProcess.h b/ProcessLib/ThermoMechanics/ThermoMechanicsProcess.h
index 23f8d0552cc18cd4edc14a1544ee3b73b2829351..b6c8f40acfe559df3ecc025ad30ca9d3461e71c6 100644
--- a/ProcessLib/ThermoMechanics/ThermoMechanicsProcess.h
+++ b/ProcessLib/ThermoMechanics/ThermoMechanicsProcess.h
@@ -11,7 +11,7 @@
 
 #include "ProcessLib/Process.h"
 
-#include "ThermoMechanicsFEM.h"
+#include "LocalAssemblerInterface.h"
 #include "ThermoMechanicsProcessData.h"
 
 namespace ProcessLib