diff --git a/inst/extdata/benchmarks/flow_free_expansion/flow_free_expansion.prj b/inst/extdata/benchmarks/flow_free_expansion/flow_free_expansion.prj
index f9be2056e7a7ecea20f2d3dbe9fe1d140718a630..3381a8267c0df692027d2d4d5a097242f85ebcf5 100644
--- a/inst/extdata/benchmarks/flow_free_expansion/flow_free_expansion.prj
+++ b/inst/extdata/benchmarks/flow_free_expansion/flow_free_expansion.prj
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="ISO-8859-1"?>
+<?xml version='1.0' encoding='ISO-8859-1'?>
 <OpenGeoSysProject>
     <mesh>cube_1x1x1_quad.vtu</mesh>
     <geometry>cube_1x1x1.gml</geometry>
@@ -18,14 +18,8 @@
                 <pressure>pressure</pressure>
             </process_variables>
             <secondary_variables>
-                <secondary_variable internal_name="sigma_xx" output_name="sigma_xx"/>
-                <secondary_variable internal_name="sigma_yy" output_name="sigma_yy"/>
-                <secondary_variable internal_name="sigma_zz" output_name="sigma_zz"/>
-                <secondary_variable internal_name="sigma_xy" output_name="sigma_xy"/>
-                <secondary_variable internal_name="epsilon_xx" output_name="epsilon_xx"/>
-                <secondary_variable internal_name="epsilon_yy" output_name="epsilon_yy"/>
-                <secondary_variable internal_name="epsilon_zz" output_name="epsilon_zz"/>
-                <secondary_variable internal_name="epsilon_xy" output_name="epsilon_xy"/>
+                <secondary_variable internal_name="sigma" output_name="sigma"/>
+                <secondary_variable internal_name="epsilon" output_name="epsilon"/>
                 <secondary_variable internal_name="velocity" output_name="velocity"/>
             </secondary_variables>
             <specific_body_force>0 0 0</specific_body_force>
@@ -56,25 +50,25 @@
                 <phase>
                     <type>Solid</type>
                     <properties>
-                        <property>
-                            <name>porosity</name>
-                            <type>Constant</type>
-                            <value>0.3</value>
-                        </property>
                         <property>
                             <name>density</name>
                             <type>Constant</type>
                             <value>1.43e3</value>
                         </property>
-                        <property>
-                            <name>biot_coefficient</name>
-                            <type>Constant</type>
-                            <value>0.6</value>
-                        </property>
                     </properties>
                 </phase>
             </phases>
             <properties>
+                <property>
+                    <name>porosity</name>
+                    <type>Constant</type>
+                    <value>0.3</value>
+                </property>
+                <property>
+                    <name>biot_coefficient</name>
+                    <type>Constant</type>
+                    <value>0.6</value>
+                </property>
                 <property>
                     <name>reference_temperature</name>
                     <type>Constant</type>
@@ -125,14 +119,8 @@
             <variables>
                 <variable>displacement</variable>
                 <variable>pressure</variable>
-                <variable>sigma_xx</variable>
-                <variable>sigma_yy</variable>
-                <variable>sigma_zz</variable>
-                <variable>sigma_xy</variable>
-                <variable>epsilon_xx</variable>
-                <variable>epsilon_yy</variable>
-                <variable>epsilon_zz</variable>
-                <variable>epsilon_xy</variable>
+                <variable>sigma</variable>
+                <variable>epsilon</variable>
                 <variable>velocity</variable>
             </variables>
             <suffix>_ts_{:timestep}_t_{:time}</suffix>
diff --git a/inst/extdata/benchmarks/flow_no_strain/flow_no_strain.prj b/inst/extdata/benchmarks/flow_no_strain/flow_no_strain.prj
index e4544f906e8a04754e9914661b7aca813c6cbb8c..e203ecc94ade7617327d643e96b7cf6179cd4678 100644
--- a/inst/extdata/benchmarks/flow_no_strain/flow_no_strain.prj
+++ b/inst/extdata/benchmarks/flow_no_strain/flow_no_strain.prj
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="ISO-8859-1"?>
+<?xml version='1.0' encoding='ISO-8859-1'?>
 <OpenGeoSysProject>
     <mesh>square_1x1_quad8_1e2.vtu</mesh>
     <geometry>square_1x1.gml</geometry>
@@ -18,14 +18,8 @@
                 <pressure>pressure</pressure>
             </process_variables>
             <secondary_variables>
-                <secondary_variable internal_name="sigma_xx" output_name="sigma_xx"/>
-                <secondary_variable internal_name="sigma_yy" output_name="sigma_yy"/>
-                <secondary_variable internal_name="sigma_zz" output_name="sigma_zz"/>
-                <secondary_variable internal_name="sigma_xy" output_name="sigma_xy"/>
-                <secondary_variable internal_name="epsilon_xx" output_name="epsilon_xx"/>
-                <secondary_variable internal_name="epsilon_yy" output_name="epsilon_yy"/>
-                <secondary_variable internal_name="epsilon_zz" output_name="epsilon_zz"/>
-                <secondary_variable internal_name="epsilon_xy" output_name="epsilon_xy"/>
+                <secondary_variable internal_name="sigma" output_name="sigma"/>
+                <secondary_variable internal_name="epsilon" output_name="epsilon"/>
                 <secondary_variable internal_name="velocity" output_name="velocity"/>
             </secondary_variables>
             <specific_body_force>0 0</specific_body_force>
@@ -56,25 +50,25 @@
                 <phase>
                     <type>Solid</type>
                     <properties>
-                        <property>
-                            <name>porosity</name>
-                            <type>Constant</type>
-                            <value>0.03</value>
-                        </property>
                         <property>
                             <name>density</name>
                             <type>Constant</type>
                             <value>2.17e3</value>
                         </property>
-                        <property>
-                            <name>biot_coefficient</name>
-                            <type>Constant</type>
-                            <value>0.6</value>
-                        </property>
                     </properties>
                 </phase>
             </phases>
             <properties>
+                <property>
+                    <name>porosity</name>
+                    <type>Constant</type>
+                    <value>0.03</value>
+                </property>
+                <property>
+                    <name>biot_coefficient</name>
+                    <type>Constant</type>
+                    <value>0.6</value>
+                </property>
                 <property>
                     <name>reference_temperature</name>
                     <type>Constant</type>
@@ -115,7 +109,7 @@
         </processes>
         <output>
             <type>VTK</type>
-            <prefix>flow_no_strain_pcs_{:process_id}</prefix>
+            <prefix>flow_no_strain</prefix>
             <timesteps>
                 <pair>
                     <repeat>1</repeat>
@@ -125,14 +119,8 @@
             <variables>
                 <variable>displacement</variable>
                 <variable>pressure</variable>
-                <variable>sigma_xx</variable>
-                <variable>sigma_yy</variable>
-                <variable>sigma_zz</variable>
-                <variable>sigma_xy</variable>
-                <variable>epsilon_xx</variable>
-                <variable>epsilon_yy</variable>
-                <variable>epsilon_zz</variable>
-                <variable>epsilon_xy</variable>
+                <variable>sigma</variable>
+                <variable>epsilon</variable>
                 <variable>velocity</variable>
             </variables>
             <suffix>_ts_{:timestep}_t_{:time}</suffix>