diff --git a/Makefile.am b/Makefile.am
index 02146969..dd2937e9 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -8,6 +8,7 @@ cpgpreprocessdir = $(includedir)/cpgpreprocess
 
 cpgpreprocess_HEADERS = cgridinterface.h preprocess.h
 
+noinst_PROGRAMS = grid_io_demo
 
 lib_LTLIBRARIES = libcpgpreprocess.la
 noinst_LTLIBRARIES = libcpgpreprocess_noinst.la
@@ -28,3 +29,6 @@ uniquepoints.h
 
 libcpgpreprocess_noinst_la_SOURCES =            \
 $(libcpgpreprocess_la_SOURCES)
+
+grid_io_demo_SOURCES = test_readvector.cpp
+grid_io_demo_LDADD = libcpgpreprocess.la
\ No newline at end of file
diff --git a/grid.h b/grid.h
new file mode 100644
index 00000000..22a4211e
--- /dev/null
+++ b/grid.h
@@ -0,0 +1,60 @@
+/*
+  Copyright 2010 SINTEF ICT, Applied Mathematics.
+
+  This file is part of the Open Porous Media project (OPM).
+
+  OPM is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  OPM is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with OPM.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef OPM_GRID_HEADER_INCLUDED
+#define OPM_GRID_HEADER_INCLUDED
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+struct UnstructuredGrid {
+    int    dimensions;
+
+    int    number_of_cells;
+    int    number_of_faces;
+    int    number_of_nodes;
+
+    int    *face_nodes;
+    int    *face_nodepos;
+    int    *face_cells;
+
+    int    *cell_faces;
+    int    *cell_facepos;
+
+    double *node_coordinates;
+
+    double *face_centroids;
+    double *face_areas;
+    double *face_normals;
+
+    double *cell_centroids;
+    double *cell_volumes;
+};
+
+typedef struct UnstructuredGrid grid_t;
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* OPM_GRID_HEADER_INCLUDED */
diff --git a/test_readvector.cpp b/test_readvector.cpp
index b4cac3d1..b167582c 100644
--- a/test_readvector.cpp
+++ b/test_readvector.cpp
@@ -1,7 +1,9 @@
 #include <iostream>
 #include <vector>
-#include <cpgpreprocess/preprocess.h>
-#include <cpgpreprocess/cgridinterface.h>
+
+#include "grid.h"
+#include "preprocess.h"
+#include "cgridinterface.h"
 
 #include "readvector.hpp"