diff --git a/src/cfs_tpfa.h b/src/cfs_tpfa.h
new file mode 100644
index 00000000..716d3b6c
--- /dev/null
+++ b/src/cfs_tpfa.h
@@ -0,0 +1,65 @@
+/*
+  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_CFS_TPFA_HEADER_INCLUDED
+#define OPM_CFS_TPFA_HEADER_INCLUDED
+
+#include "grid.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct cfs_tpfa_impl;
+struct CSRMatrix;
+
+struct cfs_tpfa_data {
+    struct CSRMatrix     *A;
+    double               *b;
+    double               *x;
+
+    struct cfs_tpfa_impl *pimpl;
+};
+
+
+struct cfs_tpfa_data *
+cfs_tpfa_construct(grid_t *G);
+
+void
+cfs_tpfa_assemble(grid_t               *G,
+                  const double         *ctrans,
+                  const double         *P,
+                  const double         *src,
+                  struct cfs_tpfa_data *h);
+
+void
+cfs_tpfa_press_flux(grid_t               *G,
+                    const double         *trans,
+                    struct cfs_tpfa_data *h,
+                    double               *cpress,
+                    double               *fflux);
+
+void
+cfs_tpfa_destroy(struct cfs_tpfa_data *h);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* OPM_CFS_TPFA_HEADER_INCLUDED */