diff --git a/Tests/BaseLib/TestConfigTree.cpp b/Tests/BaseLib/TestConfigTree.cpp
index ff5568b9a97df4e8a76f888638effc9b2b9364fc..c75db7edcb4d7984841527b64480452f2a689930 100644
--- a/Tests/BaseLib/TestConfigTree.cpp
+++ b/Tests/BaseLib/TestConfigTree.cpp
@@ -120,7 +120,7 @@ TEST(BaseLibConfigTree, Get)
             "<vector_bad1>x 1 2a</vector_bad1>"
             "<vector_bad2>0 1 2a</vector_bad2>"
             ;
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     Callbacks cbs;
     {
@@ -256,7 +256,7 @@ TEST(BaseLibConfigTree, IncompleteParse)
             "<pt x=\"0.5\">1</pt>"
             "<pt2 x=\"0.5\" y=\"1.0\" z=\"2.0\" />"
             ;
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     Callbacks cbs;
     {
@@ -297,7 +297,7 @@ TEST(BaseLibConfigTree, CheckRange)
             "<int>0</int>"
             "<int>1</int>"
             "<int>2</int>";
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     Callbacks cbs;
     {
@@ -336,7 +336,7 @@ TEST(BaseLibConfigTree, GetSubtreeList)
             "<val><int>0</int></val>"
             "<val><int>1</int></val>"
             "<val><int>2</int></val>";
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     Callbacks cbs;
     {
@@ -368,7 +368,7 @@ TEST(BaseLibConfigTree, GetParamList)
             "<int>2</int>"
             "<int2 a=\"b\">3</int2>"
             "<int3>4<error/></int3>";
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     Callbacks cbs;
     {
@@ -419,7 +419,7 @@ TEST(BaseLibConfigTree, GetValueList)
             "<int>0</int>"
             "<int>1</int>"
             "<int>2</int>";
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     Callbacks cbs;
     {
@@ -454,7 +454,7 @@ TEST(BaseLibConfigTree, NoConversion)
             "<ign/>"
             "<ign2/><ign2/><ign2/>"
             ;
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     Callbacks cbs;
     {
@@ -506,7 +506,7 @@ TEST(BaseLibConfigTree, NoConversion)
 TEST(BaseLibConfigTree, BadKeynames)
 {
     const char xml[] = "";
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     Callbacks cbs;
     {
@@ -550,7 +550,7 @@ TEST(BaseLibConfigTree, StringLiterals)
     const char xml[] =
             "<s>test</s>"
             "<t>Test</t>";
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     Callbacks cbs;
     {
@@ -576,7 +576,7 @@ TEST(BaseLibConfigTree, MoveConstruct)
             "<s>test</s>"
             "<t>Test</t>"
             "<u>data</u>";
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     Callbacks cbs;
     {
@@ -620,7 +620,7 @@ TEST(BaseLibConfigTree, MoveAssign)
             "<s>test</s>"
             "<t>Test</t>"
             "<u>data</u>";
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     Callbacks cbs;
     {
diff --git a/Tests/MaterialLib/TestCapillaryPressureSaturationModel.cpp b/Tests/MaterialLib/TestCapillaryPressureSaturationModel.cpp
index 22824522f544c41fa3a2ef17f9906e1112c9d5b5..425953b2ff5c690c68a11d6d9a3dfc35c1e44c5b 100644
--- a/Tests/MaterialLib/TestCapillaryPressureSaturationModel.cpp
+++ b/Tests/MaterialLib/TestCapillaryPressureSaturationModel.cpp
@@ -28,7 +28,7 @@ using namespace MaterialLib::PorousMedium;
 std::unique_ptr<CapillaryPressureSaturation> createCapillaryPressureModel(
     const char xml[])
 {
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
     BaseLib::ConfigTree conf(ptree, "", BaseLib::ConfigTree::onerror,
                              BaseLib::ConfigTree::onwarning);
     auto const& sub_config = conf.getConfigSubtree("capillary_pressure");
diff --git a/Tests/MaterialLib/TestFluidDensity.cpp b/Tests/MaterialLib/TestFluidDensity.cpp
index 9e459749b2200aa6e4f9113bf741847f04297667..1b6bf024d9134721157dc1890820c23a631f0340 100644
--- a/Tests/MaterialLib/TestFluidDensity.cpp
+++ b/Tests/MaterialLib/TestFluidDensity.cpp
@@ -28,7 +28,7 @@ using ArrayType = MaterialLib::Fluid::FluidProperty::ArrayType;
 // Test density models.
 std::unique_ptr<FluidProperty> createTestFluidDensityModel(const char xml[])
 {
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
     BaseLib::ConfigTree conf(ptree, "", BaseLib::ConfigTree::onerror,
                              BaseLib::ConfigTree::onwarning);
     auto const& sub_config = conf.getConfigSubtree("density");
diff --git a/Tests/MaterialLib/TestFluidProperties.cpp b/Tests/MaterialLib/TestFluidProperties.cpp
index a09d31572bb7fcc91592ddaba77a7243c16a2e75..8d41ff57eabbe454d69232925a78db8d882439b3 100644
--- a/Tests/MaterialLib/TestFluidProperties.cpp
+++ b/Tests/MaterialLib/TestFluidProperties.cpp
@@ -30,7 +30,7 @@ using ArrayType = MaterialLib::Fluid::FluidProperty::ArrayType;
 
 std::unique_ptr<FluidProperties> createTestFluidProperties(const char xml[])
 {
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
     BaseLib::ConfigTree conf(ptree, "", BaseLib::ConfigTree::onerror,
                              BaseLib::ConfigTree::onwarning);
     auto const& sub_config = conf.getConfigSubtree("fluid");
diff --git a/Tests/MaterialLib/TestFluidSpecificHeatCapacityModel.cpp b/Tests/MaterialLib/TestFluidSpecificHeatCapacityModel.cpp
index abb9d1e8af8766b57cdc547cd67a62d0d8635c79..6beeed8cceb19fab8d500c4e5da65a8ea6c9ee9c 100644
--- a/Tests/MaterialLib/TestFluidSpecificHeatCapacityModel.cpp
+++ b/Tests/MaterialLib/TestFluidSpecificHeatCapacityModel.cpp
@@ -30,7 +30,7 @@ using ArrayType = MaterialLib::Fluid::FluidProperty::ArrayType;
 std::unique_ptr<FluidProperty> createSpecificFluidHeatCapacityModel(
     const char xml[])
 {
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
     BaseLib::ConfigTree conf(ptree, "", BaseLib::ConfigTree::onerror,
                              BaseLib::ConfigTree::onwarning);
     auto const& sub_config = conf.getConfigSubtree("specific_heat_capacity");
diff --git a/Tests/MaterialLib/TestFluidThermalConductivityModel.cpp b/Tests/MaterialLib/TestFluidThermalConductivityModel.cpp
index 67b2e33cd72f3ab699d402f0d3c0e80043d61c74..eef10327548080885697c197cd4309323528ccab 100644
--- a/Tests/MaterialLib/TestFluidThermalConductivityModel.cpp
+++ b/Tests/MaterialLib/TestFluidThermalConductivityModel.cpp
@@ -31,7 +31,7 @@ using ArrayType = MaterialLib::Fluid::FluidProperty::ArrayType;
 std::unique_ptr<FluidProperty> createFluidThermalConductivityModel(
     const char xml[])
 {
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
     BaseLib::ConfigTree conf(ptree, "", BaseLib::ConfigTree::onerror,
                              BaseLib::ConfigTree::onwarning);
     auto const& sub_config = conf.getConfigSubtree("thermal_conductivity");
diff --git a/Tests/MaterialLib/TestFluidViscosity.cpp b/Tests/MaterialLib/TestFluidViscosity.cpp
index 3130935ec4e37cc37e402f1b65fd05f2db7fbad7..6a7bef22790ae714c7e55d56c589e2f3bb45a291 100644
--- a/Tests/MaterialLib/TestFluidViscosity.cpp
+++ b/Tests/MaterialLib/TestFluidViscosity.cpp
@@ -27,7 +27,7 @@ using ArrayType = MaterialLib::Fluid::FluidProperty::ArrayType;
 
 std::unique_ptr<FluidProperty> createTestViscosityModel(const char xml[])
 {
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
     BaseLib::ConfigTree conf(ptree, "", BaseLib::ConfigTree::onerror,
                              BaseLib::ConfigTree::onwarning);
     auto const& sub_config = conf.getConfigSubtree("viscosity");
diff --git a/Tests/MaterialLib/TestMPL.cpp b/Tests/MaterialLib/TestMPL.cpp
index 0dcb8795121036017dad61cc1dd003596f20de4e..7ed654f1689acac2e6bd1fb7a2bc8e53f3c23325 100644
--- a/Tests/MaterialLib/TestMPL.cpp
+++ b/Tests/MaterialLib/TestMPL.cpp
@@ -18,12 +18,13 @@
 #include "MaterialLib/MPL/CreateMedium.h"
 #include "MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.h"
 #include "ParameterLib/Parameter.h"
+#include "Tests/TestTools.h"
 
 namespace Tests
 {
 std::unique_ptr<MPL::Medium> createTestMaterial(std::string const& xml)
 {
-    auto const ptree = readXml(xml.c_str());
+    auto const ptree = Tests::readXml(xml.c_str());
     BaseLib::ConfigTree conf(ptree, "", BaseLib::ConfigTree::onerror,
                              BaseLib::ConfigTree::onwarning);
     auto const& config = conf.getConfigSubtree("medium");
@@ -41,7 +42,7 @@ std::unique_ptr<MaterialPropertyLib::Property> createTestProperty(
         BaseLib::ConfigTree const& config)>
         createProperty)
 {
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
     BaseLib::ConfigTree conf(ptree, "", BaseLib::ConfigTree::onerror,
                              BaseLib::ConfigTree::onwarning);
     auto const& sub_config = conf.getConfigSubtree("property");
diff --git a/Tests/MaterialLib/TestPorousMediumStorage.cpp b/Tests/MaterialLib/TestPorousMediumStorage.cpp
index 29bdda8b84fb8fc0d060b9bc7dcc2f056aea9ae1..bc475ed885c79afd13c1c3fac3b87aeb40a12447 100644
--- a/Tests/MaterialLib/TestPorousMediumStorage.cpp
+++ b/Tests/MaterialLib/TestPorousMediumStorage.cpp
@@ -24,7 +24,7 @@ using namespace MaterialLib::PorousMedium;
 
 std::unique_ptr<Storage> createTestStorageModel(const char xml[])
 {
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
     BaseLib::ConfigTree conf(ptree, "", BaseLib::ConfigTree::onerror,
                              BaseLib::ConfigTree::onwarning);
     auto const& sub_config = conf.getConfigSubtree("storage");
diff --git a/Tests/MaterialLib/TestRelativePermeabilityModel.cpp b/Tests/MaterialLib/TestRelativePermeabilityModel.cpp
index e69e43900b8e552e0509374cc51000438d1e268f..b4cae71a6f2fb006c83f00363e371fe690035dfe 100644
--- a/Tests/MaterialLib/TestRelativePermeabilityModel.cpp
+++ b/Tests/MaterialLib/TestRelativePermeabilityModel.cpp
@@ -28,7 +28,7 @@ using namespace MaterialLib::PorousMedium;
 std::unique_ptr<RelativePermeability> createRelativePermeabilityModel(
     const char xml[])
 {
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
     BaseLib::ConfigTree conf(ptree, "", BaseLib::ConfigTree::onerror,
                              BaseLib::ConfigTree::onwarning);
     auto const& sub_config = conf.getConfigSubtree("relative_permeability");
diff --git a/Tests/MathLib/TestLinearSolver.cpp b/Tests/MathLib/TestLinearSolver.cpp
index 417b49f512d910d8668dfa67bc9e1a7f23d691cd..b0a5cf497cccc911841b6f0002a9cfbfb9cb09f1 100644
--- a/Tests/MathLib/TestLinearSolver.cpp
+++ b/Tests/MathLib/TestLinearSolver.cpp
@@ -283,7 +283,7 @@ TEST(MPITest_Math, CheckInterface_PETSc_Linear_Solver_basic)
             "  </parameters>"
             "  <prefix>ptest1</prefix>"
             "</petsc>";
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     checkLinearSolverInterface<MathLib::PETScMatrix,
                                MathLib::PETScVector,
@@ -317,7 +317,7 @@ TEST(MPITest_Math, CheckInterface_PETSc_Linear_Solver_chebyshev_sor)
             "  </parameters>"
             "  <prefix>ptest2</prefix>"
             "</petsc>";
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     checkLinearSolverInterface<MathLib::PETScMatrix,
                                MathLib::PETScVector,
@@ -353,7 +353,7 @@ TEST(MPITest_Math, CheckInterface_PETSc_Linear_Solver_gmres_amg)
             "  </parameters>"
             "  <prefix>ptest3</prefix>"
             "</petsc>";
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
 
     checkLinearSolverInterface<MathLib::PETScMatrix,
                                MathLib::PETScVector,
diff --git a/Tests/MathLib/TestPiecewiseLinearCurve.cpp b/Tests/MathLib/TestPiecewiseLinearCurve.cpp
index 750cbaaaf4245b83cdb635baf305482df84f8859..37bcef80f91d32edb69018b86bbd50ddd7a55433 100644
--- a/Tests/MathLib/TestPiecewiseLinearCurve.cpp
+++ b/Tests/MathLib/TestPiecewiseLinearCurve.cpp
@@ -24,7 +24,7 @@
 template <typename CurveType>
 std::unique_ptr<CurveType> createPiecewiseLinearCurve(const char xml[])
 {
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
     BaseLib::ConfigTree conf(ptree, "", BaseLib::ConfigTree::onerror,
                              BaseLib::ConfigTree::onwarning);
     auto const& sub_config = conf.getConfigSubtree("curve");
diff --git a/Tests/NumLib/TestODEInt.cpp b/Tests/NumLib/TestODEInt.cpp
index c216470fe0d3bfc839a619dee320b85aa0ce5e30..1e7e4467aa1f6be9119cbb7b5b9a1ae7609b5498 100644
--- a/Tests/NumLib/TestODEInt.cpp
+++ b/Tests/NumLib/TestODEInt.cpp
@@ -41,7 +41,7 @@ createLinearSolver()
         "<petsc><parameters>"
         "-ksp_type bcgs -pc_type sor -ksp_rtol 1e-24 -ksp_max_it 100 -ksp_initial_guess_nonzero false"
         "</parameters></petsc>";
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
     BaseLib::ConfigTree config(ptree, "", BaseLib::ConfigTree::onerror,
                                BaseLib::ConfigTree::onwarning);
     return std::make_unique<GlobalLinearSolver>("", &config);
diff --git a/Tests/NumLib/TestTimeSteppingEvolutionaryPIDcontroller.cpp b/Tests/NumLib/TestTimeSteppingEvolutionaryPIDcontroller.cpp
index 74d297a3c4b828944a86263357448373272e8f9e..81f00799763b1acb6995de952f93d244fd970f2d 100644
--- a/Tests/NumLib/TestTimeSteppingEvolutionaryPIDcontroller.cpp
+++ b/Tests/NumLib/TestTimeSteppingEvolutionaryPIDcontroller.cpp
@@ -25,7 +25,7 @@
 std::unique_ptr<NumLib::TimeStepAlgorithm> createTestTimeStepper(
     const char xml[])
 {
-    auto const ptree = readXml(xml);
+    auto const ptree = Tests::readXml(xml);
     BaseLib::ConfigTree conf(ptree, "", BaseLib::ConfigTree::onerror,
                              BaseLib::ConfigTree::onwarning);
     auto const& sub_config = conf.getConfigSubtree("time_stepping");
diff --git a/Tests/ParameterLib/Parameter.cpp b/Tests/ParameterLib/Parameter.cpp
index ababafa72d26265bf2b6da050bde886e4d25379a..b35966abb1d8599e5a97894a56e12b4871f604db 100644
--- a/Tests/ParameterLib/Parameter.cpp
+++ b/Tests/ParameterLib/Parameter.cpp
@@ -35,7 +35,7 @@ std::unique_ptr<Parameter<double>> constructParameterFromString(
              std::unique_ptr<MathLib::PiecewiseLinearInterpolation>> const&
         curves = {})
 {
-    auto const xml_ptree = readXml(xml.c_str());
+    auto const xml_ptree = Tests::readXml(xml.c_str());
     BaseLib::ConfigTree config_tree(xml_ptree, "", BaseLib::ConfigTree::onerror,
                                     BaseLib::ConfigTree::onwarning);
     auto parameter_base = createParameter(config_tree, meshes, curves);
diff --git a/Tests/TestTools.cpp b/Tests/TestTools.cpp
index ae7772f8b5869e8bf475ac40b02fa3fa20e7f1d4..98ff64c9484f76251c8c30dc9d1c12f5e19262d8 100644
--- a/Tests/TestTools.cpp
+++ b/Tests/TestTools.cpp
@@ -11,8 +11,9 @@
 
 #include "Tests/TestTools.h"
 
-boost::property_tree::ptree
-readXml(const char xml[])
+namespace Tests
+{
+boost::property_tree::ptree readXml(const char xml[])
 {
     boost::property_tree::ptree ptree;
     std::istringstream xml_str(xml);
@@ -22,3 +23,5 @@ readXml(const char xml[])
         boost::property_tree::xml_parser::trim_whitespace);
     return ptree;
 }
+
+}  // namespace Tests
diff --git a/Tests/TestTools.h b/Tests/TestTools.h
index 6a9bce301c5d90ba9bdacfff09cb414f80a0ed0c..f15110466d9ddc45c80ea02cb11dcbcd812fa898 100644
--- a/Tests/TestTools.h
+++ b/Tests/TestTools.h
@@ -24,6 +24,7 @@
 #define ASSERT_ARRAY_EQ(E,A,N)\
     for (std::size_t i=0; i<(unsigned)(N); i++) \
         ASSERT_EQ((E)[i], (A)[i]);
-
-boost::property_tree::ptree
-readXml(const char xml[]);
+namespace Tests
+{
+boost::property_tree::ptree readXml(const char xml[]);
+}  // namespace Tests