diff --git a/src/VTKWriter_unit_tests.hpp b/src/VTKWriter_unit_tests.hpp
index a9d79f63959a6da3a7acb319a4fff0a4ca82d7ad..c34568a66a60e2712ba32d8a84e94e97c6f85f78 100644
--- a/src/VTKWriter_unit_tests.hpp
+++ b/src/VTKWriter_unit_tests.hpp
@@ -200,7 +200,7 @@ BOOST_AUTO_TEST_CASE( vtk_writer_use_graph3D )
 
 	// check that match
 
-	bool test = compare("vtk_graph_v2.vtk","vtk_graph_test.vtk");
+	bool test = compare("vtk_graph_v2.vtk","vtk_graph_v2_test.vtk");
 	BOOST_REQUIRE_EQUAL(true,test);
 }
 
@@ -278,7 +278,7 @@ BOOST_AUTO_TEST_CASE( vtk_writer_use_graph3D_edge )
 
 	// check that match
 
-	bool test = compare("vtk_graph_v4.vtk","vtk_graph_test.vtk");
+	bool test = compare("vtk_graph_v4.vtk","vtk_graph_v4_test.vtk");
 	BOOST_REQUIRE_EQUAL(true,test);
 }
 
@@ -363,7 +363,7 @@ BOOST_AUTO_TEST_CASE( vtk_writer_use_graph2D )
 
 	// check that match
 
-	bool test = compare("vtk_graph_v3.vtk","vtk_graph_test.vtk");
+	bool test = compare("vtk_graph_v3.vtk","vtk_graph_v3_test.vtk");
 	BOOST_REQUIRE_EQUAL(true,test);
 }
 
diff --git a/vtk_graph_test.vtk b/vtk_graph_test.vtk
index 4d9aa58f9f6e46fd29f87e915aab585624703661..10f1f680d1c7c73995d68850fbb7c276662943a0 100644
--- a/vtk_graph_test.vtk
+++ b/vtk_graph_test.vtk
@@ -138,3 +138,372 @@ LOOKUP_TABLE default
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diff --git a/vtk_graph_v2_test.vtk b/vtk_graph_v2_test.vtk
new file mode 100644
index 0000000000000000000000000000000000000000..a2a6d3ede4391ff95c3c04b4fa5b5a691b564fe0
--- /dev/null
+++ b/vtk_graph_v2_test.vtk
@@ -0,0 +1,458 @@
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+Graph
+ASCII
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+POINTS 8 float
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diff --git a/vtk_graph_v3_test.vtk b/vtk_graph_v3_test.vtk
new file mode 100644
index 0000000000000000000000000000000000000000..69044dc1e5167dccf31635b1862b5ae602fa37c4
--- /dev/null
+++ b/vtk_graph_v3_test.vtk
@@ -0,0 +1,118 @@
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diff --git a/vtk_graph_v4_test.vtk b/vtk_graph_v4_test.vtk
new file mode 100644
index 0000000000000000000000000000000000000000..7d0a1174f466e8a399ef3299e47cfe57f4a5e86d
--- /dev/null
+++ b/vtk_graph_v4_test.vtk
@@ -0,0 +1,227 @@
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