diff --git a/CMakeLists.txt b/CMakeLists.txt
index e4c7843e..7364d410 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.10)
 set(MOORDYN_MAJOR_VERSION 2)
 set(MOORDYN_MINOR_VERSION 6)
-set(MOORDYN_PATCH_VERSION 0)
+set(MOORDYN_PATCH_VERSION 1)
 set(MOORDYN_VERSION ${MOORDYN_MAJOR_VERSION}.${MOORDYN_MINOR_VERSION})
 project(Moordyn VERSION ${MOORDYN_VERSION})
 
diff --git a/tests/fortran_bindings.f90 b/tests/fortran_bindings.f90
index e1b689bd..79d9a3d5 100644
--- a/tests/fortran_bindings.f90
+++ b/tests/fortran_bindings.f90
@@ -50,7 +50,7 @@ program main
       stop 1
     end if
     do j = 1, 3
-      x(3 * i + j) = r(j)
+      x(3 * (i_point - 1) + (j - 1)) = r(j - 1)
     end do
   end do
 
diff --git a/tests/vtk.cpp b/tests/vtk.cpp
index 4d026c6a..6ff03f74 100644
--- a/tests/vtk.cpp
+++ b/tests/vtk.cpp
@@ -87,7 +87,7 @@ write_vtk_by_instances()
 		}
 		std::stringstream filepath;
 		filepath << fs::temp_directory_path().string() << "/"
-		         << "vtk_body_" << body_i << ".00000.vtu";
+		         << "vtk_body_" << body_i << ".00000.vtp";
 		std::cout << "***     Saving on '" << filepath.str().c_str() << "'..."
 		          << std::endl;
 
@@ -116,7 +116,7 @@ write_vtk_by_instances()
 		}
 		std::stringstream filepath;
 		filepath << fs::temp_directory_path().string() << "/"
-		         << "vtk_rod_" << rod_i << ".00000.vtu";
+		         << "vtk_rod_" << rod_i << ".00000.vtp";
 		std::cout << "***     Saving on '" << filepath.str().c_str() << "'..."
 		          << std::endl;
 
@@ -146,7 +146,7 @@ write_vtk_by_instances()
 		}
 		std::stringstream filepath;
 		filepath << fs::temp_directory_path().string() << "/"
-		         << "vtk_point_" << point_i << ".00000.vtu";
+		         << "vtk_point_" << point_i << ".00000.vtp";
 		std::cout << "***     Saving on '" << filepath.str().c_str() << "'..."
 		          << std::endl;
 
@@ -176,7 +176,7 @@ write_vtk_by_instances()
 		}
 		std::stringstream filepath;
 		filepath << fs::temp_directory_path().string() << "/"
-		         << "vtk_line_" << line_i << ".00000.vtu";
+		         << "vtk_line_" << line_i << ".00000.vtp";
 		std::cout << "***     Saving on '" << filepath.str().c_str() << "'..."
 		          << std::endl;