diff --git a/src/cfs_tpfa.c b/src/cfs_tpfa.c
index 90d58eeb3..0fea19f90 100644
--- a/src/cfs_tpfa.c
+++ b/src/cfs_tpfa.c
@@ -992,34 +992,48 @@ cfs_tpfa_assemble(grid_t                  *G,
 
 /* ---------------------------------------------------------------------- */
 void
-cfs_tpfa_press_flux(grid_t                 *G,
-                    flowbc_t               *bc,
-                    well_t                 *W,
-                    int                     np,
-                    const double           *trans,
-                    const double           *pmobf,
-                    const double           *gravcap_f,
-                    struct completion_data *wdata,
-                    struct cfs_tpfa_data   *h,
-                    double                 *cpress,
-                    double                 *fflux,
-                    double                 *wpress,
-                    double                 *wflux)
+cfs_tpfa_press_increment(grid_t               *G,
+                         well_t               *W,
+                         struct cfs_tpfa_data *h,
+                         double               *cpress_inc,
+                         double               *wpress_inc)
 /* ---------------------------------------------------------------------- */
 {
     /* Assign cell pressure directly from solution vector */
-    memcpy(cpress, h->x, G->number_of_cells * sizeof *cpress);
+    memcpy(cpress_inc, h->x, G->number_of_cells * sizeof *cpress_inc);
 
+    if (W != NULL) {
+        assert (wpress_inc != NULL);
+
+        /* Assign well BHP directly from solution vector */
+        memcpy(wpress_inc, h->x + G->number_of_cells,
+               W->number_of_wells * sizeof *wpress_inc);
+    }
+}
+
+
+/* ---------------------------------------------------------------------- */
+void
+cfs_tpfa_flux(grid_t                 *G,
+              flowbc_t               *bc,
+              well_t                 *W,
+              int                     np,
+              const double           *trans,
+              const double           *pmobf,
+              const double           *gravcap_f,
+              const double           *cpress,
+              const double           *wpress,
+              struct completion_data *wdata,
+              double                 *fflux,
+              double                 *wflux)
+/* ---------------------------------------------------------------------- */
+{
     compute_flux(G, bc, np, trans, pmobf, gravcap_f, cpress, fflux);
 
     if ((W != NULL) && (wdata != NULL)) {
         assert (wpress != NULL);
         assert (wflux  != NULL);
 
-        /* Assign well BHP directly from solution vector */
-        memcpy(wpress, h->x + G->number_of_cells,
-               W->number_of_wells * sizeof *wpress);
-
         compute_wflux(W, np, wdata, cpress, wpress, wflux);
     }
 }
diff --git a/src/cfs_tpfa.h b/src/cfs_tpfa.h
index acd809ea4..7cbec29a6 100644
--- a/src/cfs_tpfa.h
+++ b/src/cfs_tpfa.h
@@ -60,19 +60,25 @@ cfs_tpfa_assemble(grid_t                  *G,
                   struct cfs_tpfa_data    *h);
 
 void
-cfs_tpfa_press_flux(grid_t                 *G,
-                    flowbc_t               *bc,
-                    well_t                 *W,
-                    int                     np,
-                    const double           *trans,
-                    const double           *pmobf,
-                    const double           *gravcap_f,
-                    struct completion_data *wdata,
-                    struct cfs_tpfa_data   *h,
-                    double                 *cpress,
-                    double                 *fflux,
-                    double                 *wpress,
-                    double                 *wflux);
+cfs_tpfa_press_increment(grid_t               *G,
+                         well_t               *W,
+                         struct cfs_tpfa_data *h,
+                         double               *cpress_inc,
+                         double               *wpress_inc);
+
+void
+cfs_tpfa_flux(grid_t                 *G,
+              flowbc_t               *bc,
+              well_t                 *W,
+              int                     np,
+              const double           *trans,
+              const double           *pmobf,
+              const double           *gravcap_f,
+              const double           *cpress,
+              const double           *wpress,
+              struct completion_data *wdata,
+              double                 *fflux,
+              double                 *wflux);
 
 void
 cfs_tpfa_fpress(grid_t               *G,