diff --git a/uniquepoints.h b/uniquepoints.h
index 54ae0c37..867001d6 100644
--- a/uniquepoints.h
+++ b/uniquepoints.h
@@ -2,8 +2,9 @@
 #define UNIQUEPOINTS_H
 
 
-void finduniquepoints(const struct grdecl *g,  /* input */
-		      int                 *p,  /* for each z0 in zcorn, z0 = z[p0] */
-		      sparse_table_t      *z); /* list of uniq zcorn valules for each pillar*/
+int finduniquepoints(const struct grdecl *g,  /* input */
+		     int                 *p,  /* for each z0 in zcorn, z0 = z[p0] */
+		     sparse_table_t      *z); /* list of uniq zcorn valules for each pillar*/
 
 #endif
+